Damping Technology

[Robert Taylor]

Hello Kiwi Bikers!

My name is Max McAllister, and I am President of Traxxion Dynamics, Inc.

:yes:

I know many of you are familiar with our name and our products. Robert T did an exceptional job of representing our products for several years, and he sold dozens and dozens of NZ racers and bikers our AK-20 Axxion Cartridge Kits.

I know that dozens of races and several NZ National Championships were won using Traxxion AK-20s, at least through 2005.

It was only through reading here that I learned our parts were "in the bin", and "direct rip offs of Ohlins Products", and "consigned to history" in NZ.

I am saddened to hear this!

I will accept the statement that my design is a "copy/ ripoff of Ohlins 98 model Superbike pistons with Race Tech size porting" as a compliment of sorts...

For certain, we have never copied anything Ohlins has ever made, to this day. They still have not made any piston, of any diameter, that looks like our parts. Ohlins Superbike forks use 25mm internals, and we don't use or believe in, use, or recommend 25mm cartridges unless you are stuck with them.

A copy is a copy...

I was the first to marry a valve high-flow (Typically Showa, but also modeled by Race Tech) piston with a digressive external ring into a single part. Both OEM Showa and Race Tech made a high flow linear piston, and the Ohlins SB piston was digressive only on the low speed side (dishing shim stack)... the tiny ports in the Ohlins piston (high speed) are actually progressive, which is one key area where bump harshness comes from. Anyplace that has bumps will appreciate having these removed. I have heard through the grapevine you have some bumps in NZ!

So if taking facets of other designs and combining them into a fashion that no other company had ever done, makes me a rip-off artist... then I guess I am guilty. I thought I was being inventive...:cool:

Anyway, as far as our products being "consigned to history"... I can't see how our kits were good enough for Tony Rees to win a championship with in 2005, and in 2006 or 7 they are "in the bin".

Our products have not stopped winning races elsewhere in the world!

In fact, we are the 1st, and only company in the world to have a fully Supersport Legal, bolt in, gas-charged fork cartridge kit, the AK-Gas. We have sold scores of sets of these around the world. Their quality and function is unmatched. At least one other major suspension manufacturer in the world will be selling them under a private label in 2008.

AMA Privateer Jake Holden (Jordan Motorsports) used our AK-Gas cartridges on his GSXR1000 Superstock Bike to stand on the box many times in 2007, consistently outqualifying and beating the factory teams. At the final race of the year at Laguna Seca, he Set Pole, won the race, and Set the Lap Record.
(PS, he did this without a single valving change or adjustment during the entire 2007 racing season...).

Consigned to History?

In the Bin?

I don't think so. ;)


One thing I have found to be fact: Suspension tuners in every country on Earth think there is something special and hard to work with at the tracks in their country, and they convince their local racers of the same. A bump is a bump, a hole is a hole, a crack is a crack. They all exist in tracks all over the world. :weird:

I do undertand that your bumps are pointing down from the earth and ours point up here in the States... but your bikes should weigh less, and hit the bumps with less force since you are hangin' off the bottom of the earth...:killingme ... seriously, though...

I have worked at racetracks in the USA, Canada, Japan, Austrailia, Qatar, England, France, Italy, and Spain. It's not the black magic it's cracked up to be.

I have only seen one track in the world that was so bad, I wasn't sure any brand of suspension mattered, and that was Shubenacadie, in Nova Scotia, far Eastern Canada... the snow and ice that's there for months on end destroys the pavement, LITERALLY. Other than that... there's not been any track I have seen that required anything mystical to make a bike go around it.

We have gone to great lengths to make products that work for racers at all levels, that don't require constant rework (never mind having to be reworked before you even use them) and the constant attention of an expert tuner. Couple that with our pricing which is far below that of any comparable product, and I think you will find Traxxion products to be a winning choice, and they will add great value to your racing program.

If you have any questions, please email me, max@traxxion.com .

Sincerely,

Max McAllister
President
Traxxion Dynamics, Inc.

You know Max I got to thinking in the middle of the night about the relative merits of bending shim stack type mid-valves as opposed to fixed / limited stroke mid valves.
Lets be clear that this is a tech discussion devoid of politics and if any ''third party'' posts trivialising or patronising what has been said then it abundantly proves a point.
As you well realise the conventional check plate type mid valve has a clearly definable area of ''dead stroke'', that being the check plate opening distance, because it is the first thing that moves when the fork is under compression. Most compression damping control is via the base compression pistons in the bottom of the cartridge.
In the bending shim stack type mid valve there isnt a sudden opening of a check plate but a modulated flow contolled by a shim stack. With a properly arranged / developed shim stack and port sizes it will modulate limited flow at small fork shaft velocities but with also lots of allowable deflection can move much greater volume of fluid ( than a checkplate type ) at higher fork velocities. Much less emphasis is therefore placed on the base compression pistons ( although they are by no means redundant ) and the fork damping action becomes much closer to a shock in action, albeit an emulsion shock.
I see that at least the basic principle ( not neccessarily the intended function and true benefits ) are appearing in more and more oem sportbike forks. In quoting my beloved viking cartridges the compression flow ports through what they now call the main piston ( also the rebound piston ) are huge in size with a very responsive shim stack with lots of allowable deflection. With the proper settings these forks ride the bumps quite well. I imagine K-Tech cartridges are similiar in principle.
Last season we were still using checkplate rebound pistons as we had no pre-testing time. These old pistons are now ''consigned to the bin'' !
I do agree that gas charged cartridges are the future, as with everything there is a ''gestation period'' for the market to accept it due to the extra cost. The set I purchased off you are still in circulation and will probably be raced with again this season and certainly when Craig Shirriffs used them he made very favourable comments.
Yes bumps are bumps and we have a very high ratio of circuits with them. I cannot answer for your circuits but we have a lot of emphasis on reducing excessive rear end acceleration squat off slow exit speed corners. Thats an area we work with lots with rear shocks. No shock out of the box be it WP, Penske or Ohlins has adequate squat control. In the case of your beloved Penskes your own piston addresses that problem nicely but my criticism is that the setting step changes are a little coarse. Thats where I think lots of shims rather than a few have benefit.
The shock Shaun refers to in code is a marriage of components that I put together. Ohlins 46mm body tube and shaft machined to accept a bullnose rebound needle, Traxxion piston adapted to fit, Ohlins top out spring system and hose reservoir accepted to fit Penske hi / lo speed end adjuster. Ohlins low friction rebound piston sourced from their automotive division. What Shaun doesnt know or realise is that amount of fluid the 46mm piston and 16mm shaft combination pushes is quite different to your setup within the Penske installation of around 43 - 44mm ( ? ) and 5/8 inch shaft. This took a lot of ( and I mean a lot ) of dyno runs to get right. The benefit of the hose reservoir is that the shock is now more readily adaptable to different bikes. I gained knowledge out of this exercise, but certainly recovered much much less than my true costs.
This shock works very well, but time doesnt stand still and I would have to say we have got the TTX36 working at another level with ongoing development. There are many ways to skin a cat and this is an interesting one. But like new products with new ways of working there are too many people working with them internationally with either a ham fisted approach and much less than adequate product knowledge. Working with suspension units I believe needs a solid background of having formally trained and worked in related trades requiring engineering precision, plus a clear head, at all times. Combine that with riders who can provide clear and concise feedback.
I am at odds with you though that suspension units can be made that dont need tuning from circuit to circuit. I think in the States there is a big problem in that many blue chip products are sold just as a ''tool'' and then the end user is left to find a tuner to optimise the base setting. If he is lucky he will find a good tuner. In my case I can at least sleep in the knowledge that we pre-optimise the product to the stated rider stats and speed as much as possible prior to sending out and then follow through from there. Especially the very top guys will always be looking to try something further and Shaun will vouch that I was always pulling things apart to attempt to make them work better.

[Robert Taylor]

That is kind of like saying, "I like my pants even if they are weird:scooter:








Rude of me again, sorry night Rob

Perhaps you werent spanked on the bottom hard enough when you were naughty as a child!

[tri boy]

That is kind of like saying, "I like my pants even if they are weird:scooter:


If you saw my clothing style, you would understand some of my thought patterns.:wacko:;)

[JD Racing]

As you well realise the conventional check plate type mid valve has a clearly definable area of ''dead stroke'', that being the check plate opening distance, because it is the first thing that moves when the fork is under compression. Most compression damping control is via the base compression pistons in the bottom of the cartridge.
In the bending shim stack type mid valve there isnt a sudden opening of a check plate but a modulated flow contolled by a shim stack. With a properly arranged / developed shim stack and port sizes it will modulate limited flow at small fork shaft velocities but with also lots of allowable deflection can move much greater volume of fluid ( than a checkplate type ) at higher fork velocities.

An interesting discussion guys:

Surely the dead stroke is determined by the spring force or preload on the checkplate, this can be tuned to give any characteristics, yes it's opening can be abrupt but there are ways around this.
I don't understand how you determine that a midvalve will be able to flow more than a check plate at higher shaft velocities, most check plates that I have seen move a sufficeint distance that means any restriction to flow is purely determined by the port dimensions.

[Shaun Harris]

If you saw my clothing style, you would understand some of my thought patterns.:wacko:;)



If you saw my skinny arse and mouth without teeth, you would know why all say that I am an ugly bugger:eek: but who really cares eh

[Mental Trousers]

If you saw my skinny arse and mouth without teeth, you would know why all say that I am an ugly bugger:eek: but who really cares eh
Mate, you were ugly before.

[Shaun]

Mate, you were ugly before.


Prick, and morning to you as well mate

[Shaun]

The shock Shaun refers to in code is a marriage of components that I put together. Ohlins 46mm body tube and shaft machined to accept a bullnose rebound needle, Traxxion piston adapted to fit, Ohlins top out spring system and hose reservoir accepted to fit Penske hi / lo speed end adjuster. ( So a copy):niceone:


Rob, could you please define your understanding of "copyrite" that you continiously mention! and please explain what you mean when you refer to " People who copy others idea's" aka above!

( A big part of why I used to love working with you, WE used to try a lot of different parts for me to give you a reasnable opinion from a rider's point of view on how the worked)



I gained knowledge out of this exercise, but certainly recovered much much less than my true costs.

Same here Rob. it used to cost me a lot of money to go to a race track to test and develop these units, ie petrol for travel, a day off work, petrol for bike, tyres for bike, wear and tear on the bike, track rental fee;s etc etc:Oi:
1 test day, approx $ 750-00 :devil2:


and Shaun will vouch that I was always pulling things apart to attempt to make them work better.

As per every time I refer to you, and your true skill:niceone: in your set up surgery required for the Ohlin's work and development that you do here Robert, you are bloody brilliant in this role, thanks for your enthusiasm and commitment, and I would want to use you again to work on the Ohlin's shock, if I ever was to use one ever again:apint:

[Robert Taylor]

An interesting discussion guys:

Surely the dead stroke is determined by the spring force or preload on the checkplate, this can be tuned to give any characteristics, yes it's opening can be abrupt but there are ways around this.
I don't understand how you determine that a midvalve will be able to flow more than a check plate at higher shaft velocities, most check plates that I have seen move a sufficeint distance that means any restriction to flow is purely determined by the port dimensions.

It is indeed very interesting and there is no textbook material about it! The Ohlins 25mm piston used in their cartridges has huge flow area and no restrictor stop plate for the shim stack. Its flow rate is greater than the previous check plate piston arrangement. BUT, it also modulates the flow by opening the door only as much as is required, not its open by this amount and thats what youve got!

The spring force on that checkplate can indeed be tuned ( within the limitations of such a system )but you are always having to be mindful of introducing harshness. As you will know, we often remove midvalves and fit check plates in mx stuff to give more compliance etc. In road and road race stuff there is only a third of the travel than mx so the damping has to ''build'' right away, not a mm or so later when the train is already runaway.

When in the Ohlins cartridges we ''binned'' the old style pistons and went to the ''mid valve'' type the rider feedback and lap times improved.

[Robert Taylor]

An interesting discussion guys:

Surely the dead stroke is determined by the spring force or preload on the checkplate, this can be tuned to give any characteristics, yes it's opening can be abrupt but there are ways around this.
I don't understand how you determine that a midvalve will be able to flow more than a check plate at higher shaft velocities, most check plates that I have seen move a sufficeint distance that means any restriction to flow is purely determined by the port dimensions.

Max if he has time to reply may well come back with a plausible argument totally different to mine and I would respect him about it.

[Robert Taylor]

As per every time I refer to you, and your true skill:niceone: in your set up surgery required for the Ohlin's work and development that you do here Robert, you are bloody brilliant in this role, thanks for your enthusiasm and commitment, and I would want to use you again to work on the Ohlin's shock, if I ever was to use one ever again:apint:

There has been a bunch of shocks ( and steering dampers ) coming out of Thailand that are a blatant rip off of Ohlins ( even a plagiarised name ) Made out of sawdust and very very poor function. Made for volume sale and commercial gain. A world away from a one off special. Over and out, Ive got serious work to do.

[Shaun Harris]

Max if he has time to reply may well come back with a plausible argument totally different to mine and I would respect him about it.


Hope so!

This place is so cool now that you and Max are here, ( But Max is from the USA and does have a huge customer base there and europe, and is talking to his customers a lot already, so may not get here very often at all) you guys can inform as many as you can on the engineering/testing/theory/development side of things, as this is an area that you re both experts, :headbang: perhaps Max a little more due to his engineering/manufacturing side of his proven buisness:love:


I will just carry on selling people the product that they choose to buy through me, ( Even Ohlin's again, if you want me to Robert) as well as continue to advise on set up and so on for them, ( As I am a rider, who has proven to be reasnoable at his TRADE/CRAFT Which is riding a bike and setting it up to be ridden, from a riders point of view)

Sorry Rob, but even FROSTY could kick your arse on a bike bahahaha, way cool, all riders now have the so called experts at there service:headbang:

[Pancakes]

Yes much of what you have said is fair. But NZ does seem to be a place ( for many reasons ) where many people automatically think cheap is best and forego thought about longevity problems that almost always occur.

Totally agree! There is a culture in NZ where anything that has above average cost is often viewed as a rip off, not as the high end product it may well be. There will always be a place for safe and well functioning but maybe not as good products that cost a bit less for people lacking the budget to splash out or who don't use their bike or whatever enough to justify it. (Or who's wife feels they need to spend all the money first!)

I used to coach climbing and was often asked to train and outfit people or groups to expeditions. There were times when advice for one peice of gear might be spend as little as possible for that peice of equiptment so you can trash it or leave it without much worry. At other times I would advise that they should buy the best or lightest unit out there or not bother as the difference was massive. Comes down to people like You and Max etc who know not just what but why and how.

Still intersted to see if this YSS stuff might be half as good at half the price or not worth looking at.

[vifferman]

Still intersted to see if this YSS stuff might be half as good at half the price or not worth looking at.
For Joe Average, if it's better'n WotTheyGotNow, and cheaper'n WhatThey'dReallyLikeButSeeAsTooExpensiveToJustify, then it's a win for them. A Bargain, in fact!

Trouble is, there's no real history for YSS to consider and balance against the risk, so for the punter it's just a shot in the dark, hoping for a bargain but risking wasting their money.

[cowpoos]

For Joe Average, if it's better'n WotTheyGotNow, and cheaper'n WhatThey'dReallyLikeButSeeAsTooExpensiveToJustify, then it's a win for them. A Bargain, in fact!

Trouble is, there's no real history for YSS to consider and balance against the risk, so for the punter it's just a shot in the dark, hoping for a bargain but risking wasting their money.
how would you know its better than what you have now??

[xwhatsit]

how would you know its better than what you have now??

I've got 27-year old Honda FVQs. Of course they'll be better.

Will have to investigate these further.

[cowpoos]

Ohlins Superbike forks use 25mm internals, and we don't use or believe in, use, or recommend 25mm cartridges unless you are stuck with them.



excuse my ignorance. on this subject at times..but why is it you do not recommend use of 25mm cartridges?? I realise your AK20 kits are a 20mm cartridges [I use them on my racebike for the record]...but surely with the larger diameter you are displacing more oil per mm of travel through the piston allowing damping to build faster..I also realise the design of and the tuning has alot to do with performance..but I'm only repleying to the genralised comment you made about size...

another thing...because with the larger piston...you would be able to use larger shims...would the larger diameter shims provide a less sudden spring back under direction changes..and more progressive bending?

[vifferman]

how would you know its better than what you have now??
It's a matter of trust, until they're actually fitted and fettled and tested. So it's a risk until that happens (even with a reputable brand, which may have been set up wrongly).
Unless your current shock is totally farkt, in which case almost anything will be better.

The trust comes in a couple of flavours, the most basic of which is, "Well, I've forked out more Shekeldollarz than it would have cost me to have my existing suspension overhauled, so it stands to reason it'll be better. I hope..."
The second is, "These guys have a good reputation, one which they want to keep and enhance, so I'm paying good coin knowing that if for any reason this shock isn't what I'd hoped for, they'll put it right." This is typically right, but may not be the case if you've overstated your ability or requirements, and ended up with an oversprung, overdamped shock set up for RacerX, and with insufficient adjustment in it to make it workable for the riding you really do, which is commuting, with the occasional gentle open-road ride on shitty bumpy roads.

[Robert Taylor]

excuse my ignorance. on this subject at times..but why is it you do not recommend use of 25mm cartridges?? I realise your AK20 kits are a 20mm cartridges [I use them on my racebike for the record]...but surely with the larger diameter you are displacing more oil per mm of travel through the piston allowing damping to build faster..I also realise the design of and the tuning has alot to do with performance..but I'm only repleying to the genralised comment you made about size...

another thing...because with the larger piston...you would be able to use larger shims...would the larger diameter shims provide a less sudden spring back under direction changes..and more progressive bending?

As far as relative displacement of oil goes for any given distance of fork movement the Traxxion 12.5mm rod in its 20mm tube is the winner, at least on that score. Arguably ( and Max will beg to differ ) the response of 22mm od shims against 17mm is better. I have already seperately detailed what I see as the virtues of the bending shim stack mid valve. Then theres top out springs which we played a hell of a lot with last season, settings now adopted by Ohlins.

Sam Smith NZ600 No1 was the first to race with these cartridges and had previously raced with Traxxion that he was very happy with. He tried the Ohlins and instantly liked them better ( sorry Max ) and the settings almost one year later are better again, because Ohlins and ourselves never stop refining. There is no perfect setting!

If anyone would care to see just how incredibly easy it is to change fork springs with the Ohlins cartridges I will happily show them, this is one of the many detail features that is way cool, eliminating the pain in the butt nonsense of fiddling around with the top cap standard nonsense. No worries about setting the cap distance to equalise side to side and ensure the right range of rebound clicks etc, it winds down onto a shoulder, perfect and quick everytime. Very very well thought out and almost worth it on that score alone. Race bike suspension is also not only about performance, it is also about the ease of being able to make setting changes quickly and effortlessly.

TTX concept gas charged Ohlins cartridges in the future. Ohlins work at the very highest level of MotoGP and this technology is slowly trickling through to production.

[Mental Trousers]

The only thing you didn't roll out there are the Ohlins girls. Nice plug Robert.

[JD Racing]

It is indeed very interesting and there is no textbook material about it! The Ohlins 25mm piston used in their cartridges has huge flow area and no restrictor stop plate for the shim stack. Its flow rate is greater than the previous check plate piston arrangement. BUT, it also modulates the flow by opening the door only as much as is required, not its open by this amount and thats what youve got!

The spring force on that checkplate can indeed be tuned ( within the limitations of such a system )but you are always having to be mindful of introducing harshness. As you will know, we often remove midvalves and fit check plates in mx stuff to give more compliance etc. In road and road race stuff there is only a third of the travel than mx so the damping has to ''build'' right away, not a mm or so later when the train is already runaway.

When in the Ohlins cartridges we ''binned'' the old style pistons and went to the ''mid valve'' type the rider feedback and lap times improved.

I think it's possible to come up with just as good a solution using a different approach, if you think of how the Ohlins PRX valve works and apply that to the midvalve setting you have something that builds cartridge pressure rapidly without a harsh blow off. A shim stack midvalve needs a large shim deflection to prevent harshness at high shaft velocities, this puts a lot of strain on the shims which can lead to them taking a permanent set.

[Robert Taylor]

The only thing you didn't roll out there are the Ohlins girls. Nice plug Robert.

Not intended as a plug as such, stating the relative merits. And yes many of the native Scandinavian women are not very ugly

[JD Racing]

Yes bumps are bumps and we have a very high ratio of circuits with them. I cannot answer for your circuits but we have a lot of emphasis on reducing excessive rear end acceleration squat off slow exit speed corners. Thats an area we work with lots with rear shocks. .

A lot of the problems associated with this can be alleviated by the rider getting wise with his gearing and his engine mapping, most racers think the thing has to be screaming it's nuts off to go fast, lots of engine tuners and dyno operators spend all their time looking at the wrong end of the graph, get that sorted and the thing will drive rather than wanting to wheelie and spin up.

[Pancakes]

....................... And yes many of the native Scandinavian women are not very ugly

and when you post up some pics we can see if your lying or not. heheheheh

[Robert Taylor]

I think it's possible to come up with just as good a solution using a different approach, if you think of how the Ohlins PRX valve works and apply that to the midvalve setting you have something that builds cartridge pressure rapidly without a harsh blow off. A shim stack midvalve needs a large shim deflection to prevent harshness at high shaft velocities, this puts a lot of strain on the shims which can lead to them taking a permanent set.

Yes that is so but most particularly in mx application where they use very thin shims with little support on huge ports. A racing cartridge using this principle would ideally be serviced twice a season anyway and any sacked out shims replaced. A shim stack will modulate flow in a more controlled fashion than a spring. Note that the poppet on the PRX valve has nose shims that give a smooth transition from bypass bleed choke off to opening, compensating for the semi abrupt opening of a spring.

Thick less compliant nose shims give an abrupt ''knee'' on a dyno curve, thin compliant shims give a rounded knee.

Note that the Penske high speed compression adjuster is a preloadable shim stack, in all fairness a very nice piece of kit with a wide response range.

I will talk about high speed compression adjusters at another time, recent Ohlins technology with the TTX36 range has rendered their fitment almost academic.

Moderators any chance of moving the last few posts to a new thread entitled ''Damping Technology''? It has all strayed off the original subject and I think it needs to pick up from my second response to Max.

[JD Racing]

The secret lies in using a shim to allow initial deflection opening the ports a little before the whole assembly lifts.

I wouldn't be so quick to consign high speed adjusters to your bin just yet, the TTX 36 with it's limited fitment range is the only high end shock on the market to do this. I would imagine that the through shaft TTX as used by the Yamaha factory teams in GP's and WSB will eventually filter it's way down to the street market then we'll be using high and low speed compression and rebound.

[Robert Taylor]

A lot of the problems associated with this can be alleviated by the rider getting wise with his gearing and his engine mapping, most racers think the thing has to be screaming it's nuts off to go fast, lots of engine tuners and dyno operators spend all their time looking at the wrong end of the graph, get that sorted and the thing will drive rather than wanting to wheelie and spin up.

Agreed, but also ( logically ) the engine delivery shouldnt be so softened that it is over-compensating for lack of rear shock low speed damping squat control.

[Robert Taylor]

The secret lies in using a shim to allow initial deflection opening the ports a little before the whole assembly lifts.

I wouldn't be so quick to consign high speed adjusters to your bin just yet, the TTX 36 with it's limited fitment range is the only high end shock on the market to do this. I would imagine that the through shaft TTX as used by the Yamaha factory teams in GP's and WSB will eventually filter it's way down to the street market then we'll be using high and low speed compression and rebound.

No they are not in the bin as such, its just that the basic incarnation of the TTX36 does alleviate a good part of the need for it, at least in a mass market situation where you dont have a highly skilled factory technician to hand. The TTX concept is the future for Ohlins and will filter through to other models, as much was stated at the recent Ohlins distributor conference.

Already we have been building TTX36 to order for models such as SV650 on the back of Glen Williams stunning results at the recent Greymouth street races.

The through rod damper such as TTX40 is a stunning piece of kit but does require a high level of set up skill. We adapted one to fit into one of Craig Shirriffs race bikes and won races with it.

I will elaborate further about the reality of this technology when I have a little more time. The application, costs and ability of end users to understand tuning are THE overriding factors about what ends up in the marketplace for such aftermarket products.

[Coyote]

Most of this just flew over my head.

Where do you go to learn this jargon? Do you have to take an engineering course at uni or something?

[F5 Dave]

Great thread.
Amateur side question: So shims have a service life? Presumably more so in MX applications & certain arrangements more than others (light shims mentioned). How would the punter know? How does the tech know to replace?, presumably they take a set like a worn set of reeds?

[enigma51]

I think we need to test this in practice any one want to long term "borrow" me a set for the 750 I will give all my feedback exclusively to the internet

I am more than happy to test road and track usage and you will get the benefit of an average slowish rider :p

[Pancakes]

Most of this just flew over my head.

Where do you go to learn this jargon? Do you have to take an engineering course at uni or something?


They are building stuff that might not have been made in that configuration before so they get to make up the name too. I'm sending RT a case of Becks and have a feeling the "Pancake Valve" will be released in time for the 2009 European season!

[Shaun Harris]

I think we need to test this in practice any one want to long term "borrow" me a set for the 750 I will give all my feedback exclusively to the internet

I am more than happy to test road and track usage and you will get the benefit of an average slowish rider :p


DONE

I will lend you a set of forks all set up, totally built by RobT not ever touched since he last worked on them! ( If Rob wants them first for service reason's etc, A OK ) with full ohlin"s and Rob's Skill put into them for (a year ago give or take a month or 3 for these ones) for a week or so in January 08- OK ? They bolt in, no worries at all, In fact, I will fit FOC!

Then, swap them out for a set that I spoke about at the start of this thread, for you to try! And comment on.

Then, try the gear I will be working with next year, again FOC, and you have your say man, a bumps a bumps as you know I am sure:girlfight:

I do and have sold all 3, so, why not

[Robert Taylor]

Most of this just flew over my head.

Where do you go to learn this jargon? Do you have to take an engineering course at uni or something?

You first have to become a distributor of a leading suspension brand ( there are only 3 ) after years of learning the basics and proving yourself. You work at it for a decade or two. You spend literally tens of thousands of dollars in overseas travel to attend seminars. Such seminars are in depth distributor level, not something you can just buy into.You develop a very good relationship with the engineers. You must not be afraid to do very long hours and to test many things that wont work so well, but learn from it. You totally stay away from illegal substances that slowly destroy your brain.You invest 100k or so in test equipment and tooling to provide a full and proper service.

This doesnt happen overnight. Like Max said this is not black magic, but it is a lot of hard work.

A uni course in fluid dynamics would be a good start, but the real rewards are overseas.

[Robert Taylor]

Great thread.
Amateur side question: So shims have a service life? Presumably more so in MX applications & certain arrangements more than others (light shims mentioned). How would the punter know? How does the tech know to replace?, presumably they take a set like a worn set of reeds?

Yes they do develop a set and allow the forks to ''ride low'' and blow through their stroke too readily

[JD Racing]

You know Max I got to thinking in the middle of the night about the relative merits of bending shim stack type mid-valves as opposed to fixed / limited stroke mid valves.
Lets be clear that this is a tech discussion devoid of politics and if any ''third party'' posts trivialising or patronising what has been said then it abundantly proves a point.
As you well realise the conventional check plate type mid valve has a clearly definable area of ''dead stroke'', that being the check plate opening distance, because it is the first thing that moves when the fork is under compression. Most compression damping control is via the base compression pistons in the bottom of the cartridge.
In the bending shim stack type mid valve there isnt a sudden opening of a check plate but a modulated flow contolled by a shim stack. With a properly arranged / developed shim stack and port sizes it will modulate limited flow at small fork shaft velocities but with also lots of allowable deflection can move much greater volume of fluid ( than a checkplate type ) at higher fork velocities. Much less emphasis is therefore placed on the base compression pistons ( although they are by no means redundant ) and the fork damping action becomes much closer to a shock in action, albeit an emulsion shock.
I see that at least the basic principle ( not neccessarily the intended function and true benefits ) are appearing in more and more oem sportbike forks. In quoting my beloved viking cartridges the compression flow ports through what they now call the main piston ( also the rebound piston ) are huge in size with a very responsive shim stack with lots of allowable deflection. With the proper settings these forks ride the bumps quite well. I imagine K-Tech cartridges are similiar in principle.
Last season we were still using checkplate rebound pistons as we had no pre-testing time. These old pistons are now ''consigned to the bin'' !
I do agree that gas charged cartridges are the future, as with everything there is a ''gestation period'' for the market to accept it due to the extra cost. The set I purchased off you are still in circulation and will probably be raced with again this season and certainly when Craig Shirriffs used them he made very favourable comments.


Max is in a position where he pretty much has to use a check plate, using a 20mm cartridge and a 12.5mm damper rod the pressure drop across the rebound piston is far greater than with a 25mm cartridge and a 12mm rod, this pressure drop makes the piston more susceptible to cavitation if a mid valve shim stack is used.
The oem manufacturers can get away with a light stack as they use a 10mm rod and add bleeds to the piston so cavitation doesn't become an issue.
The 25mm cartridge has a much larger area and swept volume, the larger area means that to achieve the same damping force less pressure has to build in the cartridge so there is less pressure differential across the piston so a shim stack could be used without the risk of cavitation. The much larger swept volume means that the ports need to be much larger to achieve the desired flow rate and that the shims will have to deflect further to give the desired increase in valve open area. Shims are only effective at low lifts beyond this their bending characteristics change, so here a check plate can also be desirable.
Adding a shim stack to the midvalve increases the overall damping coefficient of the forks, to prevent the forks becoming too hard often the base valve then needs to be softened to compensate. Softening the base valve can lead to having a less powerfull compression adjuster.
You can't soften the base valve too much or add too much stiffness to the midvalve as it then becomes difficult to build pressure in the cartridge, this can lead to a pulsing in the cartridge at the top of the stroke. As the forks start to compress there is insufficient air pressure within the forks so the rebound piston instead of flowing through the oil pushes a slug of oil in front of it, the base valve faced with 4 times the volumetric flow rate it's designed for generates 16 times the resistance, the forks stop for a fraction of a second then the midvalve opens, the pressure drops and the above is repeated, if your hard on the brakes the forks will continue to dive the internal air pressure will rise and the forks will start to work efficiently. If you'd just brushed the brakes to check your speed you'd feel this pulsing through the bars, this was very common when Ohlins were using a massive stack of wave washers or a real heavy duty check plate spring.
The strong point about a 25mm cartridge tends to be they offer more support on the brakes, at these shaft velocities the overall damping coefficient of the 2 stacks really kicks in, providing of course that's what you want. How riders like the forks to compress on the brakes varies as much as braking styles, some riders like to brake progressively others like to wait till the very last second then grab a huge handfull of brake. Some riders like the forks to compress quickly and load the front tyre so they can get maximum feel and turn in real easy, others like a slower dive with the forks operating higher in the stroke through the turn. A lot of riders don't know what the hell they want they just use what the guy is winning uses, sometimes this is a backward step as often the guy who is winning usually has the talent to ride around on anything.

Phew, I somehow managed to write all that without being an importer of the top 3's products, how the hell did that happen.

[Ixion]

Y..

A uni course in fluid dynamics would be a good start, but the real rewards are overseas.

I did that, and this is still over my head. Is there an ABC anywher eon the web? I *think* I sort of understand what you are saying (without of course having the faintest notion who is right - two of a trade never agree!) But a little basic cramming would be good. Bear in mind that I have still not fully recovered from the abandonment of girder forks. I understood those.

[Sensei]

I have been lucky enough to try Roberts handy work on a friends bike which was used as a test bed for the AK20 kits & the Traxtion gear as well as the Ohlins internals & I can say that all of these products are such aleap ahead of the standard stuff that come in the Jap bikes that it tranforms them to where they meet their motor performance . The ins & outs of making it work tho is a skill in its self & take my hat off to Robert & others that can do this . Even better when they live in my home town . :banana:

[JD Racing]

I did that, and this is still over my head. Is there an ABC anywher eon the web? I *think* I sort of understand what you are saying (without of course having the faintest notion who is right - two of a trade never agree!) But a little basic cramming would be good. Bear in mind that I have still not fully recovered from the abandonment of girder forks. I understood those.

I don't think there is any such thing as being right, most in the trade have their own agenda and argue from that stand point, all your doing is controlling the dynamic behaviour of a sprung mass, if you spend enough time looking at something, testing, doing something for the hell of it you can make pretty much anything work and work well.

[Robert Taylor]

Max is in a position where he pretty much has to use a check plate, using a 20mm cartridge and a 12.5mm damper rod the pressure drop across the rebound piston is far greater than with a 25mm cartridge and a 12mm rod, this pressure drop makes the piston more susceptible to cavitation if a mid valve shim stack is used.
The oem manufacturers can get away with a light stack as they use a 10mm rod and add bleeds to the piston so cavitation doesn't become an issue.
The 25mm cartridge has a much larger area and swept volume, the larger area means that to achieve the same damping force less pressure has to build in the cartridge so there is less pressure differential across the piston so a shim stack could be used without the risk of cavitation. The much larger swept volume means that the ports need to be much larger to achieve the desired flow rate and that the shims will have to deflect further to give the desired increase in valve open area. Shims are only effective at low lifts beyond this their bending characteristics change, so here a check plate can also be desirable.
Adding a shim stack to the midvalve increases the overall damping coefficient of the forks, to prevent the forks becoming too hard often the base valve then needs to be softened to compensate. Softening the base valve can lead to having a less powerfull compression adjuster.
You can't soften the base valve too much or add too much stiffness to the midvalve as it then becomes difficult to build pressure in the cartridge, this can lead to a pulsing in the cartridge at the top of the stroke. As the forks start to compress there is insufficient air pressure within the forks so the rebound piston instead of flowing through the oil pushes a slug of oil in front of it, the base valve faced with 4 times the volumetric flow rate it's designed for generates 16 times the resistance, the forks stop for a fraction of a second then the midvalve opens, the pressure drops and the above is repeated, if your hard on the brakes the forks will continue to dive the internal air pressure will rise and the forks will start to work efficiently. If you'd just brushed the brakes to check your speed you'd feel this pulsing through the bars, this was very common when Ohlins were using a massive stack of wave washers or a real heavy duty check plate spring.
The strong point about a 25mm cartridge tends to be they offer more support on the brakes, at these shaft velocities the overall damping coefficient of the 2 stacks really kicks in, providing of course that's what you want. How riders like the forks to compress on the brakes varies as much as braking styles, some riders like to brake progressively others like to wait till the very last second then grab a huge handfull of brake. Some riders like the forks to compress quickly and load the front tyre so they can get maximum feel and turn in real easy, others like a slower dive with the forks operating higher in the stroke through the turn. A lot of riders don't know what the hell they want they just use what the guy is winning uses, sometimes this is a backward step as often the guy who is winning usually has the talent to ride around on anything.

Phew, I somehow managed to write all that without being an importer of the top 3's products, how the hell did that happen.

Actually Id like to see Max answer that one as it is the best description I have seen yet re the 20mm versus 25mm schools of thought, especially with respect to pressure balance.

My description of how you become conversant with suspension to a high level ( that you have clearly demonstrated ) cited clear examples of one route to do so. Add to that time overseas ( for example ) with top level race teams, not as a ''parts fitter'' but clearly involved in the deep end of working with suspension internals. This takes considerable time and years of hands on experience plus a ''touch'' that is focused towards very pedantic assembly precision. Not a job for those with a sledgehammer and ''she'll be right'' mentality. Doing a course or two does not make one an instant suspension guru.

As Ohlins has very large prescence and respect in the racing world I am assuming that you have worked with it overseas?

[Robert Taylor]

DONE

I will lend you a set of forks all set up, totally built by RobT not ever touched since he last worked on them! ( If Rob wants them first for service reason's etc, A OK ) with full ohlin"s and Rob's Skill put into them for (a year ago give or take a month or 3 for these ones) for a week or so in January 08- OK ? They bolt in, no worries at all, In fact, I will fit FOC!

Then, swap them out for a set that I spoke about at the start of this thread, for you to try! And comment on.

Then, try the gear I will be working with next year, again FOC, and you have your say man, a bumps a bumps as you know I am sure:girlfight:

I do and have sold all 3, so, why not

Bear in mind though that the pistons in these forks are for the old check plate mid valve system. And the top caps are oem which are a pain to work with compared to the Ohlins caps. All Ohlins cartridges for sportbikes are now delivered with ''bending shim stack'' mid valve type pistons, and base valves to match. So unless the very latest stuff is tested such a test would not be totally subjective. Time and technology is relentless.

[Robert Taylor]

I don't think there is any such thing as being right, most in the trade have their own agenda and argue from that stand point, all your doing is controlling the dynamic behaviour of a sprung mass, if you spend enough time looking at something, testing, doing something for the hell of it you can make pretty much anything work and work well.

Have you looked at the cartridges in the 07 ZX6? Pretty much we cant do anything with this, the cost cutting is unbeleivable and I would reasonably guess that the other manufacturers will follow suit. The market for quality aftermarket cartridges looks pretty good

[Robert Taylor]

Max is in a position where he pretty much has to use a check plate, using a 20mm cartridge and a 12.5mm damper rod the pressure drop across the rebound piston is far greater than with a 25mm cartridge and a 12mm rod, this pressure drop makes the piston more susceptible to cavitation if a mid valve shim stack is used.
The oem manufacturers can get away with a light stack as they use a 10mm rod and add bleeds to the piston so cavitation doesn't become an issue.
The 25mm cartridge has a much larger area and swept volume, the larger area means that to achieve the same damping force less pressure has to build in the cartridge so there is less pressure differential across the piston so a shim stack could be used without the risk of cavitation. The much larger swept volume means that the ports need to be much larger to achieve the desired flow rate and that the shims will have to deflect further to give the desired increase in valve open area. Shims are only effective at low lifts beyond this their bending characteristics change, so here a check plate can also be desirable.
Adding a shim stack to the midvalve increases the overall damping coefficient of the forks, to prevent the forks becoming too hard often the base valve then needs to be softened to compensate. Softening the base valve can lead to having a less powerfull compression adjuster.
You can't soften the base valve too much or add too much stiffness to the midvalve as it then becomes difficult to build pressure in the cartridge, this can lead to a pulsing in the cartridge at the top of the stroke. As the forks start to compress there is insufficient air pressure within the forks so the rebound piston instead of flowing through the oil pushes a slug of oil in front of it, the base valve faced with 4 times the volumetric flow rate it's designed for generates 16 times the resistance, the forks stop for a fraction of a second then the midvalve opens, the pressure drops and the above is repeated, if your hard on the brakes the forks will continue to dive the internal air pressure will rise and the forks will start to work efficiently. If you'd just brushed the brakes to check your speed you'd feel this pulsing through the bars, this was very common when Ohlins were using a massive stack of wave washers or a real heavy duty check plate spring.
The strong point about a 25mm cartridge tends to be they offer more support on the brakes, at these shaft velocities the overall damping coefficient of the 2 stacks really kicks in, providing of course that's what you want. How riders like the forks to compress on the brakes varies as much as braking styles, some riders like to brake progressively others like to wait till the very last second then grab a huge handfull of brake. Some riders like the forks to compress quickly and load the front tyre so they can get maximum feel and turn in real easy, others like a slower dive with the forks operating higher in the stroke through the turn. A lot of riders don't know what the hell they want they just use what the guy is winning uses, sometimes this is a backward step as often the guy who is winning usually has the talent to ride around on anything.

Phew, I somehow managed to write all that without being an importer of the top 3's products, how the hell did that happen.

Further to my first reply to your excellent description

1) I would add that it is easier to make 25mm components with more exacting tolerances and therefore less unintentional bleed ( Max is sure to disagree! )

2) Funnily enough in recent testing we have gone to progressively softer compression specs to aid corner entry / turn in. There was an initial reluctance on my part to do this because experience with the 20mm cartridges is that they tended to ( in comparison ) ''drop their lunch'' and we would ultimately perhaps have worked in the direction of stroke restrictors. So many combinations, so little time.... The better inherent brake dive control in the 25mm cartridges appears to allow more latitude to go to softer setting specs

3)The TTX cartridge stuff when it becomes available for volume commercial resale is going to be interesting. On sale very soon for MX but the road race and road guys are going to have to wait a little longer.

Sincere thanks for the stimulation!

[White trash]

Although I can offer no technical expertise to this thread, it's gotta be one of the most enjoyable and interesting articles KB has to offer.

God bless Rob, JD Racing, Max and of course our resident protaganist Shaun for joining KB.

It's an interesting website again.

[JD Racing]

Further to my first reply to your excellent description

1) I would add that it is easier to make 25mm components with more exacting tolerances and therefore less unintentional bleed ( Max is sure to disagree! )

2) Funnily enough in recent testing we have gone to progressively softer compression specs to aid corner entry / turn in. There was an initial reluctance on my part to do this because experience with the 20mm cartridges is that they tended to ( in comparison ) ''drop their lunch'' and we would ultimately perhaps have worked in the direction of stroke restrictors. So many combinations, so little time.... The better inherent brake dive control in the 25mm cartridges appears to allow more latitude to go to softer setting specs

3)The TTX cartridge stuff when it becomes available for volume commercial resale is going to be interesting. On sale very soon for MX but the road race and road guys are going to have to wait a little longer.

Sincere thanks for the stimulation!

The 20mm cartridge certainly takes a lot of work to get right, port dimensions and shimming are extremely critical, I never understood how WP had so much success with their 21mm set up and the new closed cartridge although bigger is not a lot better, now that is one set up that sits up on the brakes.

I'd heard tha Broc Parkes was testing the TTX cartridges at Losail, I'd like to see how that's packaged.

[White trash]

Excuse my ignorance but how do the TTX cartridges differ? And can I be placed on the "I want some" short list please Robert.

[Shaun]

Bear in mind though that the pistons in these forks are for the old check plate mid valve system. And the top caps are oem which are a pain to work with compared to the Ohlins caps. All Ohlins cartridges for sportbikes are now delivered with ''bending shim stack'' mid valve type pistons, and base valves to match. So unless the very latest stuff is tested such a test would not be totally subjective. Time and technology is relentless.



OK OK, so do you want me to lend you a set of forks as well, so you can set up the very latest Ohlin's ( Now 95% owned by Ohlin's again) product you can supply for our test rider above?

Only trying to help the customer net work here to make there own opinion after a test report, from a stranger to you and me.

What would you like to do here Robert?

PS, just as well you never did fill yourself with illegal product stuff in your life ever mate, other wise you may not have made it eh:beer: Good on ya:buggerd:

[Shaun]

Bear in mind though that the pistons in these forks are for the old check plate mid valve system. And the top caps are oem which are a pain to work with compared to the Ohlins caps. All Ohlins cartridges for sportbikes are now delivered with ''bending shim stack'' mid valve type pistons, and base valves to match. So unless the very latest stuff is tested such a test would not be totally subjective. Time and technology is relentless.




Sorry mate, but just to clarify here, the Ohlin's fork caps you mentioned above, are they the style You showed me in your work shop the other day that were jamming/seizing up, if the exact Ohlin's tool was not used on them?

[cowpoos]

Max is in a position where he pretty much has to use a check plate, using a 20mm cartridge and a 12.5mm damper rod the pressure drop across the rebound piston is far greater than with a 25mm cartridge and a 12mm rod, this pressure drop makes the piston more susceptible to cavitation if a mid valve shim stack is used.
The oem manufacturers can get away with a light stack as they use a 10mm rod and add bleeds to the piston so cavitation doesn't become an issue.
The 25mm cartridge has a much larger area and swept volume, the larger area means that to achieve the same damping force less pressure has to build in the cartridge so there is less pressure differential across the piston so a shim stack could be used without the risk of cavitation. The much larger swept volume means that the ports need to be much larger to achieve the desired flow rate and that the shims will have to deflect further to give the desired increase in valve open area. Shims are only effective at low lifts beyond this their bending characteristics change, so here a check plate can also be desirable.
Adding a shim stack to the midvalve increases the overall damping coefficient of the forks, to prevent the forks becoming too hard often the base valve then needs to be softened to compensate. Softening the base valve can lead to having a less powerfull compression adjuster.
You can't soften the base valve too much or add too much stiffness to the midvalve as it then becomes difficult to build pressure in the cartridge, this can lead to a pulsing in the cartridge at the top of the stroke. As the forks start to compress there is insufficient air pressure within the forks so the rebound piston instead of flowing through the oil pushes a slug of oil in front of it, the base valve faced with 4 times the volumetric flow rate it's designed for generates 16 times the resistance, the forks stop for a fraction of a second then the midvalve opens, the pressure drops and the above is repeated, if your hard on the brakes the forks will continue to dive the internal air pressure will rise and the forks will start to work efficiently. If you'd just brushed the brakes to check your speed you'd feel this pulsing through the bars, this was very common when Ohlins were using a massive stack of wave washers or a real heavy duty check plate spring.
The strong point about a 25mm cartridge tends to be they offer more support on the brakes, at these shaft velocities the overall damping coefficient of the 2 stacks really kicks in, providing of course that's what you want. How riders like the forks to compress on the brakes varies as much as braking styles, some riders like to brake progressively others like to wait till the very last second then grab a huge handfull of brake. Some riders like the forks to compress quickly and load the front tyre so they can get maximum feel and turn in real easy, others like a slower dive with the forks operating higher in the stroke through the turn. A lot of riders don't know what the hell they want they just use what the guy is winning uses, sometimes this is a backward step as often the guy who is winning usually has the talent to ride around on anything.

Phew, I somehow managed to write all that without being an importer of the top 3's products, how the hell did that happen.

:scooter:


Actually Id like to see Max answer that one as it is the best description I have seen yet re the 20mm versus 25mm schools of thought, especially with respect to pressure balance.

My description of how you become conversant with suspension to a high level ( that you have clearly demonstrated ) cited clear examples of one route to do so. Add to that time overseas ( for example ) with top level race teams, not as a ''parts fitter'' but clearly involved in the deep end of working with suspension internals. This takes considerable time and years of hands on experience plus a ''touch'' that is focused towards very pedantic assembly precision. Not a job for those with a sledgehammer and ''she'll be right'' mentality. Doing a course or two does not make one an instant suspension guru.

As Ohlins has very large prescence and respect in the racing world I am assuming that you have worked with it overseas?

okay boys.....how about some pictures.... you just can't find a picture or schmeatic of a midvalve,etc on the internet!!

this is a brillent tech article...keep it up guys. very interesting!!

ps: robert...why is it the the TTX system doesn't allow for high speed adjustment externally...is the engineering to hard?

Pps: its obvious in WSBK,BSB,MotoGP,AMA etc that ohlins have gas cartridge front forks,because of the external gas resivors...are Showa,whitepower,etc use gas cartridges as well?? or just high end forks with normal [but obviously high end] cartridges inside?

[Mental Trousers]

.... lots of technical stuff ....

Phew, I somehow managed to write all that without being an importer of the top 3's products, how the hell did that happen.

Geek :innocent:

I'd also like to say it's a pleasure having Robert, Max, Shaun & JD Racing here. This is one of the few threads where I've read every post and been fascinated by the entire thread. It's fantastic stuff.

[Robert Taylor]

Sorry mate, but just to clarify here, the Ohlin's fork caps you mentioned above, are they the style You showed me in your work shop the other day that were jamming/seizing up, if the exact Ohlin's tool was not used on them?

Yes, but what is your point? I will let readers draw their own conclusions.
BTW, an adjustable pin spanner does the job and in any event undoing a fork cap irrespective of brand should be done at the fork cap, NOT the preload adjuster. Much of the oem stuff can also jam in such a way with a ham fisted approach.

[Robert Taylor]

Geek :innocent:

I'd also like to say it's a pleasure having Robert, Max, Shaun & JD Racing here. This is one of the few threads where I've read every post and been fascinated by the entire thread. It's fantastic stuff.

I wouldnt neccessarily count on Max posting prolifically as he is a busy man and is probably well over some of the nonsense and brazen mind games that can go on. ''JD'' has certainly offered some stimulation.

But hey thanks. My workload is about to go ballistic so posts will be sporadic.
One point of interest is that I have been contracted by Ohlins to help with World Superbike and Supersport pre season suspension tests at Phillip Island early next month. Any points of interest that I pick up on that are not subject to embargo I will post.

[Shaun]

Yes, but what is your point? I will let readers draw their own conclusions.
BTW, an adjustable pin spanner does the job and in any event undoing a fork cap irrespective of brand should be done at the fork cap, NOT the preload adjuster. Much of the oem stuff can also jam in such a way with a ham fisted approach.


Simply curious to the fact, that is all Rob, Relax mate, you are far to young to be so stressed dude

[Robert Taylor]

OK OK, so do you want me to lend you a set of forks as well, so you can set up the very latest Ohlin's ( Now 95% owned by Ohlin's again) product you can supply for our test rider above?

Only trying to help the customer net work here to make there own opinion after a test report, from a stranger to you and me.

What would you like to do here Robert?

PS, just as well you never did fill yourself with illegal product stuff in your life ever mate, other wise you may not have made it eh:beer: Good on ya:buggerd:

1) I fit the upgrade parts and charge you the going rate which I think would be around $800 to $90 all up. I.e you pay. I throw the old parts in the bin.

2) You then lend the forks to the guy foc.

i.e this is very similiar to the deal you had with me for many years, I paid for the bits and labour, you used foc.

I have sold LOTS of these cartridges and therefore have no reason to expend more time and money to prove further.

Yes a clear head is indeed an asset.

[Mental Trousers]

I wouldnt neccessarily count on Max posting prolifically as he is a busy man and is probably well over some of the nonsense and brazen mind games that can go on. ''JD'' has certainly offered some stimulation.

But hey thanks. My workload is about to go ballistic so posts will be sporadic.
One point of interest is that I have been contracted by Ohlins to help with World Superbike and Supersport pre season suspension tests at Phillip Island early next month. Any points of interest that I pick up on that are not subject to embargo I will post.
I've had an email from Max saying as much. Still, he's extremely knowledable and articulate so his input, sporadic as it may be, is definitely welcome.

Look forward to hearing what the big boys are doing with their suspension at Phillip Island. It's an interesting track; high speed but bumpy with some steep changes in height and a couple of very slow, technical corners.

[Robert Taylor]

Simply curious to the fact, that is all Rob, Relax mate, you are far to young to be so stressed dude

Maybe you are far better at comedy than me, it is the ham fisted approach of many that is the stress raiser.

[DEATH_INC.]

okay boys.....how about some pictures.... you just can't find a picture or schmeatic of a midvalve,etc on the internet!!

this is a brillent tech article...keep it up guys. very interesting!!


I'm with Poo's, I need a pic/diagram to get my head around what it is excatly you are describing.....

[Coyote]

You first have to become a distributor of a leading suspension brand ( there are only 3 ) after years of learning the basics and proving yourself. You work at it for a decade or two. You spend literally tens of thousands of dollars in overseas travel to attend seminars. Such seminars are in depth distributor level, not something you can just buy into.You develop a very good relationship with the engineers. You must not be afraid to do very long hours and to test many things that wont work so well, but learn from it. You totally stay away from illegal substances that slowly destroy your brain.You invest 100k or so in test equipment and tooling to provide a full and proper service.

This doesnt happen overnight. Like Max said this is not black magic, but it is a lot of hard work.

A uni course in fluid dynamics would be a good start, but the real rewards are overseas.
:shit:

Well I haven't been doing drugs at least, that's a start. Don't quite have the cash to go to the South Island let alone anywhere else across water :p

I might read some stuff on wikipedia to get a vague idea...

[Shaun]

1) I fit the upgrade parts and charge you the going rate which I think would be around $800 to $90 all up. I.e you pay. I throw the old parts in the bin.

2) You then lend the forks to the guy foc.

i.e this is very similiar to the deal you had with me for many years, I paid for the bits and labour, you used foc.

I have sold LOTS of these cartridges and therefore have no reason to expend more time and money to prove further.

Yes a clear head is indeed an asset.



100% Agree to all points!

apart from the old parts in the BIN!

They are bloody good parts, and I just cannot do it, some one will be extremely happy with them, when I move them on for the same cost as standard ( Original) set up I will representing in the very near future:woohoo:

How about I just supply you with the same forks, that you know I have with the above Kit I have spoken of, (which is great):Police:

And you Just Fit! the latest spec Ohlins COMPLETE Kit, that you can, which you own! and get back after rider has hooned for a week? and then YOU FIT the next KIT? ( FOC)

Which will be my own cheap add hock bush fit parts, but worth a laugh mate:niceone:

[soundbeltfarm]

who are the big three you.s talk about?

and who is jd racing ?

[cowpoos]

ohlins,whitepower,penske or sachs [not sure about the last one..sachs I think make a shock with simialr function to the new ttx36 ohlins shocks..and am only presuming the three]

[Shaun Harris]

Maybe you are far better at comedy than me, it is the ham fisted approach of many that is the stress raiser.


Know what ya mean there Rob,

that is why I HAVE GOT, a couple of hard bastards that know how to Fight hard, to work on my customers gear, so I do not upset any one, ba hahahaha:clap:


Cheers Rob, see ya later mate:third:

[k14]

Look forward to hearing what the big boys are doing with their suspension at Phillip Island. It's an interesting track; high speed but bumpy with some steep changes in height and a couple of very slow, technical corners.
Lol, one thing, Philip Island is NOT bumpy what so ever. Manfeild, yes bumpy, Puke, yes bumpy, PI, not bumpy! :2thumbsup


Just out of curiosity Robert, you mention the new gas cartriges that some of the motogp bikes run in their front forks. Are these the second tube infront of the slider in the pic below? If not, what are they?

I'd very much like a picture or two if possible. I have no idea what you are talking about the great majority of time but some if is starting to make sense.

[Shaun Harris]

Lol, one thing, Philip Island is NOT bumpy what so ever. Manfeild, yes bumpy, Puke, yes bumpy, PI, not bumpy! :2thumbsup


Just out of curiosity Robert, you mention the new gas cartriges that some of the motogp bikes run in their front forks. Are these the second tube infront of the slider in the pic below? If not, what are they?

I'd very much like a picture or two if possible. I have no idea what you are talking about the great majority of time but some if is starting to make sense.


Some of what you just said made me fall over:buggerd:

[k14]

Some of what you just said made me fall over:buggerd:
Which part may that be?

[Shaun Harris]

Which part may that be?



I'd very much like a picture or two if possible. I have no idea what you are talking about the great majority of time but some if is starting to make sense.
Attached Thumbnails

[Shaun Harris]

Just being a smart ass as per man, I like a laugh:bash:

[k14]

I'd very much like a picture or two if possible. I have no idea what you are talking about the great majority of time but some if is starting to make sense.
Attached Thumbnails
There is an extra tube on the fork that points up infront of the fork slider. I've only seen these in motogp etc bikes, never road bikes. Are they some type of gas cartridge? Or something totally different?

Edit: I was referring to cowpoos and death asking robert for an internal pic of the ways in which fork internals work. Yeah get what you were meaning now, wasn't very well worded.

[cowpoos]

Lol, one thing, Philip Island is NOT bumpy what so ever. Manfeild, yes bumpy, Puke, yes bumpy, PI, not bumpy! :2thumbsup


Just out of curiosity Robert, you mention the new gas cartriges that some of the motogp bikes run in their front forks. Are these the second tube infront of the slider in the pic below? If not, what are they?

I'd very much like a picture or two if possible. I have no idea what you are talking about the great majority of time but some if is starting to make sense.
those second tubes are the gas resivour like a modern shock has..

[JD Racing]

If you look at the attached image the cut away cartridge shows the compression and rebound asemblies. In the centre of the picture is the rebound piston, on this picture the left hand side of the piston has a checkplate, if you replace this checkplate with a shim stack it is often termed a mid valve.

Robert I did take an 07 ZX6R cartridge apart partly because I was told it was impossible and partly because like most racers the guy was broke, as the thing is such a piece of junk from the outside I was expecting to find old early 90's ZXR400 style checkplate valving inside, however they do have the newer style Showa pistons, you need to get inventive with how to get the thing to hold together again though. I see for the new ZX10 they have decided to use the same submerged spring arrangement, I wonder if Kayaba have been instructed to make an equally poor cartridge.

[JD Racing]

Click on the link below, this downloads the Ohlins gas fork manual, in there you will find lots of schematic diagrams.

http://www.ohlins.com/Portals/0/documents/manuals/07280-07.pdf

[DEATH_INC.]

Here's a pic from racetech...looks like the same setup as a crappy old twin-tube car shock....
Now, if I get you correctly, you're adding a second compression stack to the top of the rebound piston in this pic?

[Mental Trousers]

Lol, one thing, Philip Island is NOT bumpy what so ever. Manfeild, yes bumpy, Puke, yes bumpy, PI, not bumpy! :2thumbsup

Never been there myself but I was talking to a friend who had raced there about Phillip Island a while back and reckons the secret to a good time was to figure out where there weren't bumps. I guess the tracks much smoother since the last time he was there.

[k14]

Never been there myself but I was talking to a friend who had raced there about Phillip Island a while back and reckons the secret to a good time was to figure out where there weren't bumps. I guess the tracks much smoother since the last time he was there.
Yeah it could just be all relativity. I'm used to the crappy and bumpy NZ tracks I prob didn't notice it. But the only bumpy bits I can remember are the ripple strips.

[Robert Taylor]

If you look at the attached image the cut away cartridge shows the compression and rebound asemblies. In the centre of the picture is the rebound piston, on this picture the left hand side of the piston has a checkplate, if you replace this checkplate with a shim stack it is often termed a mid valve.

Robert I did take an 07 ZX6R cartridge apart partly because I was told it was impossible and partly because like most racers the guy was broke, as the thing is such a piece of junk from the outside I was expecting to find old early 90's ZXR400 style checkplate valving inside, however they do have the newer style Showa pistons, you need to get inventive with how to get the thing to hold together again though. I see for the new ZX10 they have decided to use the same submerged spring arrangement, I wonder if Kayaba have been instructed to make an equally poor cartridge.

Thats what I expected from looking at the damping curve, its not overly progressive.

[F5 Dave]

For those interested but still at kindergarten level here are a couple of books worth the read that contain drawings with explanations.

These are aimed at general public but will progress you to primary school level. Captivating reading for the Christmas break, even all the MX sort of stuff in the first book is worth the read to absorb the style of thinking.

Both avail from Real Groovy (NZ based) or from your local shop on order. $50 well spent.

Eric Gorr's book (http://www.realgroovy.co.nz/Product/231380/Motocross-and-Off-road-Performance-Handbook)

Kevin Cameron book (http://www.realgroovy.co.nz/Product/1088465/Sportbike-Performance-Handbook)

[Robert Taylor]

There are many ways of skinning a cat! A conventional ''single tube'' damper relies on shaft displacement to move fluid to create damping. The problem is that the damping reaction is actually not instantaneous, although there have been many clever ways of minimising delay in damping response.
A through rod damper such as the car specific Ohlins TTX40 and I beleive some high level Sachs ''builds damping'' instantaneously the very moment the damper moves. Ohlins TTX40 has independent externally adjustable high speed / low speed compression and rebound damping. The really cool thing about it is it comes with a valving reference program. On your pc you can input your current settings and it shows you the damping graph. You can then input your new desired settings and it will show you the new graph(s) overlayed against the original. Before you have physically made a change.This technology though does ideally rely on suspension data logging so you can interface what is happening, plus a high level of set up knowledge and experience.
The motorcycle specific TTX36 shock absorber is not a true through rod damper as it is difficult to fit into a ''given'' recess intended for a conventional damper. But it does rely a whole lot less on shaft displacement, confirmed by its 14mm shaft size. Of internal twin tube design it recirculates the oil internally through check valved chambers and has five times the flow rate through its external adjusters than a conventional displacement damper. Its much much more instant damping control means that the damping force on both compression and rebound is a lot softer, and I have confirmed this myself with comparitive dyno runs.
There is no textbook on this and it may be subject to some argument but it appears that with conventional shaft displacement dampers the internal shim stacks are more stiff than they ideally need to be, in order to maintain decent ride height control, and in especially the case of a superbike, adequate acceleration squat control. If damping doesnt occur right now but a few milliseconds later then effectively the train has already run away. Therefore a little more force is required to arrest it, whereas a lot less force would have been required to arrest it instantly. An added external HIGH SPEED COMPRESSION adjuster will allow the user to adjust its reaction to abrupt edge bumps because it is compensating for too much damping force. Essentially it is an adjustable DUMP VALVE to bypass the main shim stacks. Usually these are arranged in the reservoir ( Ohlins 46PRX / WP / Penske ) but the best result is arguably via a main shaft adjuster ( Ohlins TT44 ) or latterly on the high response adjusters on TTX40 / TTX36.
Because the TTX36 doesnt need anything like the damping force levels of a conventional damper there is arguably rather less need for external high speed adjusters, although these technically are now available as parts taken from the second generation of TTX40.
Also consider that many or most struggle to understand high speed compression ( let alone rebound ) adjusters and how they should be tuned. Cost is also another issue, its all very well to have the bells and whistles but are you going to implicitly understand how to get the best out of it and what will be the comparitive bang for buck ratio?
Some oem forks and shocks have external high speed adjusters but it is arguable that they are installed more for marketing than function. In the case of the R6 front forks the high speed adjusters have an abysmal to no response range if the low speed adjuster is more than 6 - 7 clicks out, simply because there is then so much bypass bleed happening that it lessens the pressure applied to the internal high speed spring and hat.
Because the design of the through rod / twin chamber type dampers means that you dont have the compression adjuster regulating flow into a reservoir the damper is inherently better ''pressure balanced'' internally than a conventional damper. A damper always has to have its gas charging pressure set just high enough to preclude cavitation. With conventional Ohlins 46PRX / WP / Penske / Showa etc that pressure has to be around 150 to 210 psi. More pressure equals more seal friction and that is not something to be unconcerned about. TTX36 gas charge pressure is 88 psi.
This shock is a new design and with ongoing development from Ohlins huge R&D facility it will just get better and better. Second generation test parts we fitted to Andrew Strouds race bike yesterday have certainly confirmed that.
At the coalface of working with this stuff it is highly interesting. Cowpoos was about yesterday to help ( and ask incessant questions, some of them actually sensible ) He will I am sure testify how much work is actually involved and I would like to recite his memorable quote ''its about achieving the perfect compromise''. I think we did a little better than that but all credit to him for such a statement.

[Robert Taylor]

Excuse my ignorance but how do the TTX cartridges differ? And can I be placed on the "I want some" short list please Robert.

Gas charged and same damping principle as TTX rear. That means they will be great!

[boomer]

And I still managed to Kick Stroudys arse yesterday!!

[enigma51]

DONE

I will lend you a set of forks all set up, totally built by RobT not ever touched since he last worked on them! ( If Rob wants them first for service reason's etc, A OK ) with full ohlin"s and Rob's Skill put into them for (a year ago give or take a month or 3 for these ones) for a week or so in January 08- OK ? They bolt in, no worries at all, In fact, I will fit FOC!

Then, swap them out for a set that I spoke about at the start of this thread, for you to try! And comment on.

Then, try the gear I will be working with next year, again FOC, and you have your say man, a bumps a bumps as you know I am sure:girlfight:

I do and have sold all 3, so, why not

sweeeet sounds like a deal to me :niceone:

[enigma51]

And I still managed to Kick Stroudys arse yesterday!!

Dont forget jimmy's ass you kicked

[boomer]

Dont forget jimmy's ass you kicked

Everyone kicked Jimmies ass... remember.....DNF's Don't count!

[enigma51]

Well from the weekend i can only say that a 1098s with ohlins felt great around puke no bumps upset it even forgeting that there is no slippery clutch and getting the rear wheel to bounce like a rabbit did it feel out of shape.
but then I was not pushing it (it aint mine) so cant really comment.

So the following is my feeling on ohlins on a 1098s

I felt it could go faster just didnt feel fast on it even though i was doing similar speed through some of the corners and can actually see the speed. I was doing 178 where you straiten it up at the top of the hill and on the 750 I was doing 188 and 200 average by the end of the day. The left right up the hill did not feel bumpy and neither did the sweeper or the groove on the back straight where the 750 was getting a bit loose.

The 750 stock feels great for me the only time i feel like I needed ohlins is when i was behind boomer up the hill (puke) and he was throttling through the bumps with no rear wheel spin and no bouncing about. The ohlins was much nicer to his rear than the stock shock on the 750 granted we have different riding styles.

[JD Racing]

A through rod damper such as the car specific Ohlins TTX40 and I beleive some high level Sachs ''builds damping'' instantaneously the very moment the damper moves..................

There is no textbook on this and it may be subject to some argument but it appears that with conventional shaft displacement dampers the internal shim stacks are more stiff than they ideally need to be, in order to maintain decent ride height control, and in especially the case of a superbike, adequate acceleration squat control. If damping doesnt occur right now but a few milliseconds later then effectively the train has already run away. Therefore a little more force is required to arrest it, whereas a lot less force would have been required to arrest it instantly.


These statement that there is no damper lag in a TTX shock can only be true if there is absolutely no free bleed in the system, unless you run your TTX shock with the adjusters closed this can't be true as there is a continuous free bleeed path through the compression and rebound needles therefore the further out you run your adjusters the greater the lag.

Is instantaneous damper response strictly necesary when you have 2 big ugly spring elements in the whole system one of which needs a bit of free time to key in to the pavement surface. I have never had a big problem with shocks squatting under acceleration and certainly not to the extent that I felt a complete re-design of the whole shock was necessary.

[cowpoos]

These statement that there is no damper lag in a TTX shock can only be true if there is absolutely no free bleed in the system, unless you run your TTX shock with the adjusters closed this can't be true as there is a continuous free bleeed path through the compression and rebound needles therefore the further out you run your adjusters the greater the lag.

Is instantaneous damper response strictly necesary when you have 2 big ugly spring elements in the whole system one of which needs a bit of free time to key in to the pavement surface. I have never had a big problem with shocks squatting under acceleration and certainly not to the extent that I felt a complete re-design of the whole shock was necessary.
there is instant resistance though...at some level?

but if you have a softer valving spec...by not needing to have such a agressive spec for anti squat of a thousand....would that not net more side grip?

[JD Racing]

For there to be resistance the shock needs to move a sufficient volume of fluid through the bleed to create a damping force, the volume of displaced fluid in relation to the area of the bleed is large but you will still get some lag.

Many factors determine squat under accleration, c of g, swing arm angle, swing arm length, gearing, sprocket sizes, spring rate, fuel mapping, rider body positioning and style to name a few. If you look at the shock and how it builds damping it's more than possible to tune out squat without having to touch the main stack.

With the TTX you significantly reduce the amount of variables within the system to produce damping force, this makes it very difficult to isolate specific problems.
With a normal shock it's possible to tune for good grip without having to resort to stiff damping on the main stack. The forces fed to the shock associated with finding grip are not of a significant enough amplitude to generate damping from the main stack, with regard grip on the edge of the tyre, swing arm and chassis flex have a more significant influence.

[Mental Trousers]

With the TTX you significantly reduce the amount of variables within the system to produce damping force, this makes it very difficult to isolate specific problems.

Everything else makes sense except for that. I thought fewer variables means isolating problems is easier.

[boomer]

Everything else makes sense except for that. I thought fewer variables means isolating problems is easier.

less variables means there is a lesser ability to isolate a specific issue; all potential specific issues are now consolidated..which prevents identifying the specific issue ;)

analogy.. the more probes or reference material the greater the ability to pinpoint an issue.


Fewer variables could mean less maintenance ;)


give me :beer:

[boomer]

The 750 stock feels great for me the only time i feel like I needed ohlins is when i was behind boomer up the hill (puke) and he was throttling through the bumps with no rear wheel spin and no bouncing about. The ohlins was much nicer to his rear than the stock shock on the 750 granted we have different riding styles.

if nothing else, the shit sure does look good whilst making me look good too!

[Kornholio]

if nothing else, the shit sure does look good whilst making me look good too!


God knows, you need as much help as you can get :p :buggerd:

Merry Xmas.............

[Robert Taylor]

For there to be resistance the shock needs to move a sufficient volume of fluid through the bleed to create a damping force, the volume of displaced fluid in relation to the area of the bleed is large but you will still get some lag.

Many factors determine squat under accleration, c of g, swing arm angle, swing arm length, gearing, sprocket sizes, spring rate, fuel mapping, rider body positioning and style to name a few. If you look at the shock and how it builds damping it's more than possible to tune out squat without having to touch the main stack.

With the TTX you significantly reduce the amount of variables within the system to produce damping force, this makes it very difficult to isolate specific problems.
With a normal shock it's possible to tune for good grip without having to resort to stiff damping on the main stack. The forces fed to the shock associated with finding grip are not of a significant enough amplitude to generate damping from the main stack, with regard grip on the edge of the tyre, swing arm and chassis flex have a more significant influence.

While you have been surmising about relative benefits ( and your viewpoints / empirical knowledge is interesting ) TTX has comprehensively been at the very front at Wanganui Boxing Day races. There must be some merit in the principles given very strong presence in MotoGP and a very strong second half of Superbike etc. And dont forget Le Mans, German Touring car champs and a whole host of other series where TTX is very strong )We have not seen the best of TTX yet as development is relentless.
Its interesting to note that your posts are from a position of semi anonymity and I wonder aloud that if you were offered the Ohlins distribution if you would turn it down flat or accept it? ( I have thus far appreciated your candid comments.)
With respect to ''damping lag'' are we not talking about relativity? Suffice to also say that there is some compressibility in the oil ( the bleeding of air being a variable ) and flex in internal damper components but TTX ( and high level Sachs ) significantly reduces the other variables. I think it is ''standard fare'' that someone who favours another product ( or is pushing someone elses agenda ) will use all weapons at his ( their ) disposal to discredit when a competing product with new technology enters the marketplace in force. As for making it hard to isolate specific problems I simply dont agree, and bear in mind also that the variables we have to work with in production racing are limited by the rules.
Full and honest clarification of your position would be interesting.

[JD Racing]

I think that Ohlins have made some fantastic products and continue to do so, I don't think that everything they do is brilliant though and there are areas where they have been behind other manufacturers.
With regard the TTX it's a simple factor of I'm yet to be convinced, I've not seen a technical argument put forward to convince me that it's without doubt the way forward. The FG470's were supposed to be the way forward but no end of riders struggled with those, they didn't really get better over their production run through to the FG670's and many superbike teams teams were using the TTX 25's, now they've all been canned for the TTX 20. Although I never got to use one the technology of TT44 impressed me more, shit the manual alone was a work of art.

If Honda manage to sort out their tyre and engine woes in Moto GP I don't think their old school Showa shocks will be far away next year, they certainly did ok in the AMA, Toseland did ok with his WP's, he was pushed by Haga but then he's not using customer spec Ohlins.

[Robert Taylor]

I think that Ohlins have made some fantastic products and continue to do so, I don't think that everything they do is brilliant though and there are areas where they have been behind other manufacturers.
With regard the TTX it's a simple factor of I'm yet to be convinced, I've not seen a technical argument put forward to convince me that it's without doubt the way forward. The FG470's were supposed to be the way forward but no end of riders struggled with those, they didn't really get better over their production run through to the FG670's and many superbike teams teams were using the TTX 25's, now they've all been canned for the TTX 20. Although I never got to use one the technology of TT44 impressed me more, shit the manual alone was a work of art.

If Honda manage to sort out their tyre and engine woes in Moto GP I don't think their old school Showa shocks will be far away next year, they certainly did ok in the AMA, Toseland did ok with his WP's, he was pushed by Haga but then he's not using customer spec Ohlins.
Yep! Of course at the factory level its all in house race department stuff anyway. The TT44 I have been privileged to work with and it is a lovely piece of kit. We had a set working very well on a local race car and have since changed to TTX40,the guy loves them and is going better. Craig Shirriffs won the 600cc Sports Production champs here using one a couple of seasons back etc.
You can identify shortcomings with anyones product, for instance the coarse adjustment steps on a Penske, the less than stellar performance of WP PDS, the 4 click compression adjusters on the older Ohlins adjustable twin shocks etc.

[Shaun Harris]

Its interesting to note that your posts are from a position of semi anonymity and I wonder aloud that if you were offered the Ohlins distribution if you would turn it down flat or accept it? ( I have thus far appreciated your candid comments.)



ummmmmm, that's like the offer you made to me via a text on the 22nd of December 07, subject to Ohlin's approvale of course?

Do I now ignore that offer?

[Shaun Harris]

You can identify shortcomings with anyones product, for instance the coarse adjustment steps on a Penske, the less than stellar performance of WP PDS, the 4 click compression adjusters on the older Ohlins adjustable twin shocks etc.

etc etc etc If some one had not stood up so tall, and said there product is the best and others junk, you would not need to be on here Robert, you could acctually be doing all the re valving that you need to do to an ohlins to win races:scooter:

Keep up the good work mate

[JD Racing]

I'll reiterate what I said earlier, I'm not here to bash Ohlins I'm more interested in learning through discussion how something is the best, I'm not good at blindly following.

I'm interested in your opinion of the Penske having coarse adjustment steps, I'm guessing your refering to the stack recommendations laid out in the manual. I have always used those as a basic guide, you can insert a god few stages in between each one. Otherwise it's a pretty awesome shock, it's a shame their marketing department sucks, sorry that makes it sound like they have one.

[Robert Taylor]

Its interesting to note that your posts are from a position of semi anonymity and I wonder aloud that if you were offered the Ohlins distribution if you would turn it down flat or accept it? ( I have thus far appreciated your candid comments.)



ummmmmm, that's like the offer you made to me via a text on the 22nd of December 07, subject to Ohlin's approvale of course?

Do I now ignore that offer?

No, no anonymity as it was a reply to one of your trademark texts and you had no problem replying to it reasonably quickly. As I recall you would be interested in such an opportunity. Suffice that Ohlins requirements ( and those of their customers ) are very rigid and in my previous location it wasnt really up to the expected standard. The capital investment to meet their standards is very substanial.

[Robert Taylor]

etc etc etc If some one had not stood up so tall, and said there product is the best and others junk, you would not need to be on here Robert, you could acctually be doing all the re valving that you need to do to an ohlins to win races:scooter:

Keep up the good work mate

Historical recall comes in handy, as does some consistency in opinions. It wasnt so very long ago that I heard bleating about the standard delivered settings in Traxxion Dynamics AK20 cartridges. To that I reacted and worked and worked on an alternative spec. Good enough for at least a couple of national championships and Max told me at one stage that he had adopted our compression spec as a standard delivered setting. But we have now moved on to the 25mm Ohlins cartridges. Frankly they are working appreciably better, are better toleranced and have a longer service life.

For anyone to infer that there is a shock or cartridge on the market that ''magically'' doesnt need revalving, well that frankly is a fairy tale.

Even that Traxxion piston fitted into Penskes has a setting bank of alternative valving specs according to customer height, weight and speed etc. If you want to change the bypass bleed in the piston ( probably neccessary for low grip winter series racing ) it is then about drilling more bleed holes in the piston. So you need spare pistons at more cost. I am not saying that this is a bad system, but it is a reality.

As for my habit of revalving at races I am guilty, guilty, guilty. Gareth Jones came to me first thing in the morning at Wanganui yesterday saying there was a little too much acceleration squat in the rear end of his Bernard Racing R6. It had a setting spec that worked well with Sam Smith ( similiar height and weight ) and his Dunlop tyres. But Bernard racing runs Pirellis which load the suspension rather differently. Following a trackside revalve and some ongoing optimisation of fork spring rate, preload and oil level the job was done. Guilty and charged.

Craig Shirriffs started his test season earlier than most of the top runners and we have relentlessly refined settings since with about 5, maybe 6 revalves. That he was able to walk away with all the wins at Boxing day races yesterday is testament to his undoubted ability and also finding a valving spec that so far is working pretty damn well. But we will continue on, THERE IS NO PERFECT SETTING and anyone who thinks so is in denial.

[Robert Taylor]

I'll reiterate what I said earlier, I'm not here to bash Ohlins I'm more interested in learning through discussion how something is the best, I'm not good at blindly following.

I'm interested in your opinion of the Penske having coarse adjustment steps, I'm guessing your refering to the stack recommendations laid out in the manual. I have always used those as a basic guide, you can insert a god few stages in between each one. Otherwise it's a pretty awesome shock, it's a shame their marketing department sucks, sorry that makes it sound like they have one.

Yes, your posts are great and I hear what you are saying about not blindly following, Im like that with politics!

The Penske is indeed a clever piece of kit but like any high level shock does take some knowledge ( and committment! ) to get the best out of it. As you know they use rather less shims than an Ohlins ( and I suspect WP? ) so the setting steps are coarse, even with suppliers who fit another piston. So as you have inferred it is then a case of developing your own finer incremental steps.

In any event you have confirmed to other readers that revalving to optimise is a reality.

[DEATH_INC.]

A conventional ''single tube'' damper relies on shaft displacement to move fluid to create damping.
Not sure I follow this, wouldn't that be a twin tube? It would need displacement to push oil through the 'footvalve', whereas the monotube just pushes the piston through the oil?
Sorry for going back to the basics....

[DEATH_INC.]

the ttx damping setup soooo reminds me of the old TL shock, just with a piston instead of that big flat rotaty thing.....

[JD Racing]

Ha haa, Mr Death I hadn't thought of that but yes the principal is the same.

This discussion has certainly got me intrigued about the TTX, we have already established that on a 20mm cartridge with a 12mm damper rod the high pressure drop across the piston is difficult to regulate effectively, the TTX shock having what is effectively a 36mm damper rod displaces 3x that amount of fluid through what I'm guessing is around a 20mm piston, this must be a massive pressure drop and would need huge ports to cope with the volumetric flowrate. If it is a 20mm piston then you would be limited in your shim stack height, perhaps 5-6 shims.

Therefore if Penske's have coarse adjustments using 4-8 shims with a much larger leverage ratio then it must follow that the TTX must be worse, if a 20mm piston with a high pressure drop is difficult to regulate, how is it possible for the TTX to offer far superior tuning capabilities than anything else on the market?

[Robert Taylor]

Ha haa, Mr Death I hadn't thought of that but yes the principal is the same.

This discussion has certainly got me intrigued about the TTX, we have already established that on a 20mm cartridge with a 12mm damper rod the high pressure drop across the piston is difficult to regulate effectively, the TTX shock having what is effectively a 36mm damper rod displaces 3x that amount of fluid through what I'm guessing is around a 20mm piston, this must be a massive pressure drop and would need huge ports to cope with the volumetric flowrate. If it is a 20mm piston then you would be limited in your shim stack height, perhaps 5-6 shims.

Therefore if Penske's have coarse adjustments using 4-8 shims with a much larger leverage ratio then it must follow that the TTX must be worse, if a 20mm piston with a high pressure drop is difficult to regulate, how is it possible for the TTX to offer far superior tuning capabilities than anything else on the market?

If you send me your respective e-mail addresses I am more than happy to forward copies of the wide range of alternative damping settings and graphs. The damping graphs dont directly correlate to the ''conventional '' type shocks. In practice this has worked out to be very very good and second generation pistons and settings are currently in development. The side loading compression / rebound pistons have approximately 5 times the flow rate of a normal reservoir type valve so is easier to regulate. The pressure balance is much better than in a conventional shock allowing a much lower gas pressure ( 87 psi versus 150 - 180 ) creating much less seal drag and therefore better damper response.

[Robert Taylor]

Ha haa, Mr Death I hadn't thought of that but yes the principal is the same.

This discussion has certainly got me intrigued about the TTX, we have already established that on a 20mm cartridge with a 12mm damper rod the high pressure drop across the piston is difficult to regulate effectively, the TTX shock having what is effectively a 36mm damper rod displaces 3x that amount of fluid through what I'm guessing is around a 20mm piston, this must be a massive pressure drop and would need huge ports to cope with the volumetric flowrate. If it is a 20mm piston then you would be limited in your shim stack height, perhaps 5-6 shims.

Therefore if Penske's have coarse adjustments using 4-8 shims with a much larger leverage ratio then it must follow that the TTX must be worse, if a 20mm piston with a high pressure drop is difficult to regulate, how is it possible for the TTX to offer far superior tuning capabilities than anything else on the market?

BTW the piston is much bigger than 20mm, I will measure the size tommorrow. Ohlins thinking is that it can be more difficult to achieve damping within precise tolerances with 20mm system, plus you are right about the huge differential there would be. Prompt me tommorrow ( someone ) to measure the piston size. First sealing shim od is 22mm.

[Robert Taylor]

Ha haa, Mr Death I hadn't thought of that but yes the principal is the same.

This discussion has certainly got me intrigued about the TTX, we have already established that on a 20mm cartridge with a 12mm damper rod the high pressure drop across the piston is difficult to regulate effectively, the TTX shock having what is effectively a 36mm damper rod displaces 3x that amount of fluid through what I'm guessing is around a 20mm piston, this must be a massive pressure drop and would need huge ports to cope with the volumetric flowrate. If it is a 20mm piston then you would be limited in your shim stack height, perhaps 5-6 shims.

Therefore if Penske's have coarse adjustments using 4-8 shims with a much larger leverage ratio then it must follow that the TTX must be worse, if a 20mm piston with a high pressure drop is difficult to regulate, how is it possible for the TTX to offer far superior tuning capabilities than anything else on the market?

Yes in a funny way the rotary damper thing on the TLs was very similiar in principle. But it is hard to define how much of the damping was created by friction!
I have now measured the od of the TTX valves, 26mm. Maximum of 12 shims able to be fitted.

[Shaun]

PS Rob, Very good job on Craig Shirrifs bike it and he, looked very very good at Wanganui the other day:bye:

[DEATH_INC.]

Yes in a funny way the rotary damper thing on the TLs was very similiar in principle. But it is hard to define how much of the damping was created by friction!
I have now measured the od of the TTX valves, 26mm. Maximum of 12 shims able to be fitted.
The biggest problem I found when playing with a TL shock was the pitiful sized and shaped ports the oil had to flow through.....
Mr jd does have a point, surely it would be a lot to ask of even a 26mm valve to cope with that much oil flow.....have you found the point that you start to get resistance without the valving (shims) being the restrictor? Would it be low enough velocity to reach in the real world?

[JD Racing]

As for my habit of revalving at races I am guilty, guilty, guilty. Gareth Jones came to me first thing in the morning at Wanganui yesterday saying there was a little too much acceleration squat in the rear end of his Bernard Racing R6. It had a setting spec that worked well with Sam Smith ( similiar height and weight ) and his Dunlop tyres. But Bernard racing runs Pirellis which load the suspension rather differently. Following a trackside revalve and some ongoing optimisation of fork spring rate, preload and oil level the job was done. Guilty and charged.

Craig Shirriffs started his test season earlier than most of the top runners and we have relentlessly refined settings since with about 5, maybe 6 revalves. That he was able to walk away with all the wins at Boxing day races yesterday is testament to his undoubted ability and also finding a valving spec that so far is working pretty damn well. But we will continue on, THERE IS NO PERFECT SETTING and anyone who thinks so is in denial.

The fact that you would need to revalve your shock should you swap between Dunlop and Pirelli I find both surprising and quite alarming. Geometry changes yes but a revalve? :eek:
I'm also surprised that it would need 5 or 6 revalves before the season has even started, the picture is building up here of a shock that has an extremely limited adjustment range.

[cowpoos]

The fact that you would need to revalve your shock should you swap between Dunlop and Pirelli I find both surprising and quite alarming. Geometry changes yes but a revalve? :eek:
I'm also surprised that it would need 5 or 6 revalves before the season has even started, the picture is building up here of a shock that has an extremely limited adjustment range.
tyres are essentually part of suspension action...especially at lean angles where suspension is less effective...so when swaping brands with majorly different carcus make up [ie:very stiff sidewalls on dunlops with steep profile..pirelli's...softer side walls and more progressive profile...which I'm sure your aware of?] it would definatly alter how the hydralics on the shock need to act/re-act...much the same way if your ride ate 10kgs worth of pies for breakfast...it would alter how the suspension re-acts/act from the opposite side...so why would you not want to optimise it?? reguardless of the tool being used...Geometry changes won't always work...especially with 190hp trying to tie a rearend in knots hard on the power...

[JD Racing]

tyres are essentually part of suspension action...especially at lean angles where suspension is less effective...so when swaping brands with majorly different carcus make up [ie:very stiff sidewalls on dunlops with steep profile..pirelli's...softer side walls and more progressive profile...which I'm sure your aware of?] it would definatly alter how the hydralics on the shock need to act/re-act...much the same way if your ride ate 10kgs worth of pies for breakfast...it would alter how the suspension re-acts/act from the opposite side...so why would you not want to optimise it?? reguardless of the tool being used...Geometry changes won't always work...especially with 190hp trying to tie a rearend in knots hard on the power...

I understand all that, but then what purpose do the knobs at the top of the shock serve? Do I need an Ohlins technician with me at all times to revalve my shock for every time I raise or lower my tyre pressures, swap brands of tyre, go to a different track?

[cowpoos]

I understand all that, but then what purpose do the knobs at the top of the shock serve? Do I need an Ohlins technician with me at all times to revalve my shock for every time I raise or lower my tyre pressures, swap brands of tyre, go to a different track?
ummm...most adjustments are done with low speed damping after the fact...which the TTX has... out of interest...last weekend while I was doing my best to get in Roberts way while I was spannering for Mr Stroud...I did ask Robert if theres a reason why the TTX does not have highspeed compression adjustment on the shock...he did say you can have it...but he also explain why its not there...and I'll leave that for him to explain.

and maybe if robert feels like it...he could reiterate Andrews reaction to a straight shock change between brands...with a much lower spring rate.

[JD Racing]

ummm...most adjustments are done with low speed damping after the fact...which the TTX has... out of interest...last weekend while I was doing my best to get in Roberts way while I was spannering for Mr Stroud...I did ask Robert if theres a reason why the TTX does not have highspeed compression adjustment on the shock...he did say you can have it...but he also explain why its not there...and I'll leave that for him to explain.

and maybe if robert feels like it...he could reiterate Andrews reaction to a straight shock change between brands...with a much lower spring rate.

The difference in sidewall stiffness and it's impacts upon the shaft velocites attained by the shock can be adressed with a low speed adjuster, it has one of those.

[cowpoos]

The difference in sidewall stiffness and it's impacts upon the shaft velocites attained by the shock can be adressed with a low speed adjuster, it has one of those.
high speed shaft velocites aswell?

[TDC]

I understand all that, but then what purpose do the knobs at the top of the shock serve? Do I need an Ohlins technician with me at all times to revalve my shock for every time I raise or lower my tyre pressures, swap brands of tyre, go to a different track?

Its not brand specific (damper that is). As you are obviously aware the bleed is a bypass to direct fluid away from the shim stack, thus giving you a range of adjustability. What you are really doing is balancing the action of shim stack / piston combination against the bypass flow, assuming that the shim stack is close to perfect for a given set of conditions you would need little if any bleed / bypass and would have a good level of control at all flow rates.

Unfortunately the effect of the common bleed adjuster is most pronounced at low shaft speeds / flow rates, having less effect at the shaft speeds increase.

We really have no cost reasonable mechanism for adjusting the basic characteristics of the shim stack piston combination. We can adjust the low speed response by the bleed adjuster to a point, but we quickly end up in the undesirable place of having to compromise the damping response at one shoft speed to effect the target area, not ideal.

Hence we are forced regardless of brand of device to re-valve to suite the rider (including weight, height, what he she had for breakfast, style, and sometimes how they are feeling on the day), tyre, machine (including geometry, linkage ratios, weight distribution, etc) track, and conditions.....

It is only by getting the response profile of the stack / piston combination right in the first instance that we can approach ideal (or fastest for a given bike rider track combo). As progress is made the dampers like the Ohlins TTX40 and the Sachs equivalent as fitted to the MV Senna are beginning to allow us to have better high speed adjustability (when compared to the blow off valves of some) but the problem of balance between the low speed and mid speed response has not been adequately dealt with by anybody to date.

So until somebody produces a damper with adjustments that effect the various parts of the speed range with no adverse effects to other shaft speeds other than the target range, I guess we are stuck with with optimizing what we have by the only means available (read re-valve). But then again it would be entertaining watching the greater percentage of the population try to set up a shock with say 3 or 4 adjusters each for comp and bump, but at least we wouldn't have to re-valve very often......

Simply you can't tune in to a shock via the external adjusters performance that wasn't in there in the first place, regardless of brand, so you have to get your hands dirty.....

[cowpoos]

The difference in sidewall stiffness and it's impacts upon the shaft velocites attained by the shock can be adressed with a low speed adjuster, it has one of those.
I'm actully thinking...maybe you might need to have a play with one of these TTX36 shockies to try and find its virtues for your own interest???

[TDC]

The difference in sidewall stiffness and it's impacts upon the shaft velocites attained by the shock can be adressed with a low speed adjuster, it has one of those.

As you open up the adjuster you loose a measure of control at the wheel. The stopwatch would strongly suggest that better result can be had by keeping the bleed flows small and having a shim stack with the correct characteristics for the given conditions.

I was personally skeptical and largely held your view point for quite some time, but RT has demonstrated to me in convincing fashion that he was right all along.....

[JD Racing]

As you open up the adjuster you loose a measure of control at the wheel. The stopwatch would strongly suggest that better result can be had by keeping the bleed flows small and having a shim stack with the correct characteristics for the given conditions.

I was personally skeptical and largely held your view point for quite some time, but RT has demonstrated to me in convincing fashion that he was right all along.....

If it was squatting too much you would surely close up the adjuster.
MY point though is that one this shocks main selling points in all the promotional material fromOhlins is the performance of external adjustment, what your telling me is that if you use this adjuster you'll loose rear wheel control.

[TDC]

If it was squatting too much you would surely close up the adjuster.
MY point though is that one this shocks main selling points in all the promotional material fromOhlins is the performance of external adjustment, what your telling me is that if you use this adjuster you'll loose rear wheel control.

If the bike was squatting too much I would probably look at the rear geometry (read ride height) first, I don't believe that you can control squat especially on liter class bikes by hydraulic action alone.

However, the action of the compression adjuster is rather good, certainly a wider range of useful settings than a lot of other designs. But if you want the best out of it, it does respond rather well to a bit of tweaking / optimization.

Poos is right you really should try one, I would be very surprised if you were not very impressed!

[JD Racing]

What I'm looking for is someone to give me a proper technical explanation of why I should drop that amount of dollars on a new shock, not just spend the money and you'll arrive at the promised land.
Perhaps if you have one you can enlighten me a little.
I read in a magazine a quote from Ohlins press office about how when Rossi first tried the shock he didn't want it taken out of his bike... that was it, nothing else, we'll overlook the fact that it's a completely different shock, but to me my first question would be WHY???
What does it do that the previous shock didn't?
What can I expect to feel during the transitional phases of a turn?
How will it impact upon my tyre conservation during a race?

My questioning so far has led me to believe that it's a very sensitive to tyre choice with a poor range of adjustment, prove me wrong, give me a good reason to lever these dollars out of my pocket before the wife spends the money on shoes.

[cowpoos]

My questioning so far has led me to believe that it's a very sensitive to tyre choice with a poor range of adjustment, prove me wrong, give me a good reason to lever these dollars out of my pocket before the wife spends the money on shoes.


no that would be your selective comprehension...


I think maybe...your either taking the piss...or your trying to discredit people?

[TDC]

What I'm looking for is someone to give me a proper technical explanation of why I should drop that amount of dollars on a new shock, not just spend the money and you'll arrive at the promised land.
Perhaps if you have one you can enlighten me a little.
I read in a magazine a quote from Ohlins press office about how when Rossi first tried the shock he didn't want it taken out of his bike... that was it, nothing else, we'll overlook the fact that it's a completely different shock, but to me my first question would be WHY???
What does it do that the previous shock didn't?
What can I expect to feel during the transitional phases of a turn?
How will it impact upon my tyre conservation during a race?

My questioning so far has led me to believe that it's a very sensitive to tyre choice with a poor range of adjustment, prove me wrong, give me a good reason to lever these dollars out of my pocket before the wife spends the money on shoes.

When I first put a TTX36 on my ZX10 last year (displacing a very well sorted 46 PRXLS) I was immediately impressed, actually stunned would be a better description.

As for the technical reason, the method of operation suggests that because of the full flow design this shock will build damping faster, that is with a smaller amount of shaft travel. I have seen you quite rightly point out if the shock has bleed it can't have instantaneous damping (not to mention compressibility of the working fluid etc). While it has bleed like a (dare I say) conventional shaft displacement device when you think about the percentage of flow that goes through the bleed assembly on this style of shock to the percentage of flow on a TTX bleed, the TTX has a significantly lower percentage of bleed.

Lets face it on a conventional shock the piston moves in response to a bump and a shock wave of fluid hits the comp adjuster making it swing open (hence the mandated small flow rates of this part of the device) it chokes and all the while not much damping has happened. Next as pressure builds the big and relatively heavy compression stack opens on the main piston as it can finally overcome the oil film attraction / stick of the shims against the piston surface and inertia then pressure on the top of the shock drops fast. Next assuming that the shaft is a reasonable size the displacement of this once again builds pressure in the top of the shock and it sort of falls in to equilibrium eventually after a few pressure spikes which are obviously reflected in the observed operation of the damper.

On the TTX all of the fluid (the same as the conventional as it starts to move) displaced by the piston is applied to the single compression circuit. (that by the way flows through the rebound bypass to make it to the other side of the main piston meaning that the dead stroke between compression and rebound is greatly reduced) Hence the damping builds very fast, far faster than the conventional designs without the sudden drop off as the other circuit starts to work. This faster build of damping and its stability has a big effect on a motorcycle with its poor sprung to unsprung weight ratio.

Theory is wonderful, but how does it work in real life? I found that the TTX gave simply unbelievable results on poor road surfaces, in fact the worse the road surface the better the TTX performed! On really smooth road sections its better but seemingly not by a whole lot, but the moment you encounter bumps, even small ones the difference is huge.

Tyre life increased more than a little bit! I get about 30% improvement in trye life (Metz Race Techs) over the aforementioned 46PRXLS.

What can you expect to feel, well pretty much nothing. The characteristics of the shock are so neutral its odd at first, which very quickly turns to increased levels of confidence after just a few corners. It just sticks, at first I though it was lacking feel, it wasn't it just had more traction available everywhere it took awhile to re find the improved limits of adhesion.

Its useful range of rebound adjustment for a given bike spring etc combination is small. But at the same time this wasn't really a complaint just an observation. Then useful compression adjustment range is very wide, and importantly rather linear as well.

Is it sensitive to tyre choice?, sort of but less so than conventional shocks. They as supplied are very adaptable, however if you are prepared to loose some of the adjustment / adaptability range and optimize if for a particular trye construction (read Dunlop v's the rest pretty much) there are small but useful gains to be had.

These things out of the box sans a change of spring if required are really very good indeed. Would I have any hesitation in recommending a TTX36, none....

[JD Racing]

We really have no cost reasonable mechanism for adjusting the basic characteristics of the shim stack piston combination. We can adjust the low speed response by the bleed adjuster to a point, but we quickly end up in the undesirable place of having to compromise the damping response at one shoft speed to effect the target area, not ideal.

Hence we are forced regardless of brand of device to re-valve to suite the rider (including weight, height, what he she had for breakfast, style, and sometimes how they are feeling on the day), tyre, machine (including geometry, linkage ratios, weight distribution, etc) track, and conditions.....

A couple of very good posts TDC, this one and the riding impressions one were very stimulating for the brain, thanks for taking the time to write them.

I don't know if you have had much to do with Penske or Maxton/Koni shocks but their high speed adjuster does change the shim stack characteristics. The Penske is a far nicer and far easier to use, the adjuster working on a shim stack in the reservoir, the Maxton adjusts the preload on the main piston. The Penske adjuster works in the lower of the highspeed range so that at certain settings there is some overlap, this overlap area is particularly usefull allowing you to tune the two together to find a setting that may have required a revalve with another style of adjuster.

[JD Racing]

no that would be your selective comprehension...


I think maybe...your either taking the piss...or your trying to discredit people?

Robert believes in the product he imports and see's it as being the future with regard shock technology. I'm a born skeptic but can appreciate the technology involved in the TTX, there is information I need in order to believe that the old style of shock is flawed to the extent it needs a complete redesign and if it is then this is the way forward. Luckily for us all Robert has taken the time to share information with us, nobody representing any other manufacturer has made the effort. I've learn't a considerable amount from our exchanges, and I'm quite sure that asking questions or making points that stimulate debate does not discredit anyone.

[Robert Taylor]

A couple of very good posts TDC, this one and the riding impressions one were very stimulating for the brain, thanks for taking the time to write them.

I don't know if you have had much to do with Penske or Maxton/Koni shocks but their high speed adjuster does change the shim stack characteristics. The Penske is a far nicer and far easier to use, the adjuster working on a shim stack in the reservoir, the Maxton adjusts the preload on the main piston. The Penske adjuster works in the lower of the highspeed range so that at certain settings there is some overlap, this overlap area is particularly usefull allowing you to tune the two together to find a setting that may have required a revalve with another style of adjuster.

I too thank TDC for the effort he has put into his posts. It is as well to remind that on the TTX design the external compression adjuster is not regulating flow into the reservoir, as it would on a conventional shaft displacement damper. Shaft size is 14mm so it displaces a lot less fluid than say a WP 18mm or Penske 5/8 inch. And there are no pressure balance problems inherent in ''flow regulation into the reservoir '' designs.
I am well aware of the overlap between low speed and high speed settings on the Penske, and therefore how you can shape the damping curve below about 250mm/second. But the reality is that unless you have a very knowledgable suspension technician to hand with lots and lots of setup experience and ( preferably ) a dyno to have tested and thoroughly understood how you can manipulate same then it is just not a holy grail. To that end I can well remember Shaun being troubled in understanding how this worked at a race meeting and coming and asking me several times. I also dont favour the rebound action with this design and I believe that Ohlins have the best rebound damping response in terms of finding off corner traction. While its an oversimplification to say so, off corner traction is all about rebound.
The race car specific TTX40 has 4 external adjusters i.e low and high speed compression plus low and high speed rebound, plus a valving reference program. The external response range is fantastic, but even then there are alternative internal setting parts, this gives over a million possible setting combinations. To get the very very best out of it you need top level datalogging and technicians that can understand it. There is only one set up like that here in this pacific basket case, Carl Hansens TVR Tuscan race car.
You mentioned in a previous post the Ohlins TT44, another lovely piece of kit. It had 3 compression adjusters, a ''true'' low speed adjuster, mid speed and high speed. The low speed adjuster worked exactly like if you had a range of main shaft bleed jets, except you could quickly twist it a few clicks externally instead of laboriously lifting the lid on the shock, changing the jet and rebleeding it. Or in the case of a Penske, disassembling it and drilling another bleed hole in the piston! Meaning you need at not inconsiderable expense spare pistons. Lets also not forget that with EVERY brand of shock you need to revalve and respring acording to customer height weight and speed, to suggest otherwise would be mischievous and misleading. A 5 foot 60kg rider is going to require something quite different to 6 foot 110 kg.
Here in NZ we also race through the winter in conditions of very low grip placing an emphasis on ideally being able to optimise very low shaft speed bleed. And I will re-emphasise, with a conventional shaft displacement shock that means pulling it apart and (relatively quickly) changing a shaft bleed jet, drilling the piston or changing the piston. As the ''nose'' of a damping curve is primarily effected by internal bleed size the external low speed adjuster has very little effect and is in reality a mid speed adjuster.
EXCEPT TT44, TTX40 and in a similiar way TTX36. If you were only allowed 2 external adjusters on that TT44 it would be a no brainer, rebound and that wonderful very low speed compression adjuster, analogous to being able to externally adjust internal shaft jet size. Wonderful for quickly adjusting damper response for low grip/ wet track conditions etc.
Interestingly I offered one of these dampers to Shaun several seasons back and he for whatever reasons didnt commit. Craig Shirriffs subsequently embraced the concept and comprehensively won a 600 title with it.
The TTX36 also has similiar low speed damping response and as stated previously is just going to get better and better whilst the development budgets in other camps appears to be a little stagnant.
In a weeks time I will be contracted by Ohlins to help with World Superbike pre season testing. We will see how different the stuff is that is used by these teams.
For the road race Nationals we will have 3 technicians to hand to look after our customers, that is an important part of the equation.

[JD Racing]

I'm personally very interested in the electronically mapped shock that WP are working on, they have a gps system which tells a control unit exactly where the bike is on the track and then via an electronic control valve adjusts the shock accordingly.

[cowpoos]

GPS is give or take 3 foot acurate...and not in anyone direction...I would hate a major damping change happening at the wrong time...in fact that sounds dangerous!!

[HDTboy]

I'm fairly sure there are differing levels of accuracy amongst GPS systems, Poo.

That sounds like an interesting concept. Why haven't motorcycle suspension manufacturers gone down the road of varying viscosity fluids (http://en.wikipedia.org/wiki/Magnetorheological_fluid)? Such as in the Ferrari 599 and C6 Corvette?

[JD Racing]

I'm sure they don't intend using that one sensor in isolation, just as you wouldn't solely use a throttle position sensor to control your fuelling. Were you to also use parameters from the throttle position sensor, brake pressure sensors, gyro, fork and shock pots I'm sure you could make it pretty accurate after all Moto Gp bikes use a similar system to control fuelling for each corner.

[Shaun]

GPS is give or take 3 foot acurate...and not in anyone direction...I would hate a major damping change happening at the wrong time...in fact that sounds dangerous!!



So, do you not like it when your stearing damper does it job then? ie, a major change in damping:doh:

Stearing dampers work well when they do not fall off ( Because fitted wrong) or brake

[cowpoos]

I'm fairly sure there are differing levels of accuracy amongst GPS systems, Poo.


ummm...yep I'm sure there is...but the USA military arn't very well known for sharing their toys...



but as it stands 3 foot is pretty good acuracy for a GPS system

[Shaun]

I'm sure they don't intend using that one sensor in isolation, just as you wouldn't solely use a throttle position sensor to control your fuelling. Were you to also use parameters from the throttle position sensor, brake pressure sensors, gyro, fork and shock pots I'm sure you could make it pretty accurate after all Moto Gp bikes use a similar system to control fuelling for each corner.



Hey, can you go and teach the rest of the GP paddock about this wonderfull electronic age we now live in, we might just see them going a bit quicker, safely.

[cowpoos]

I'm sure they don't intend using that one sensor in isolation, just as you wouldn't solely use a throttle position sensor to control your fuelling. Were you to also use parameters from the throttle position sensor, brake pressure sensors, gyro, fork and shock pots I'm sure you could make it pretty accurate after all Moto Gp bikes use a similar system to control fuelling for each corner.
yes...A similar system to how the fueling/ignition on MOTOgp bikes work would be good...but would reliy on interacting with the bikes ECU? so would have to be brand specific I suppose?? Havn't other companys gone down the path of electronicly varible suspension on motorcycles before??

[JD Racing]

a 10s search on google brings up:

http://www.racelogic.co.uk/?show=VBOX-Products-Basestation

[Robert Taylor]

So, do you not like it when your stearing damper does it job then? ie, a major change in damping:doh:

Stearing dampers work well when they do not fall off ( Because fitted wrong) or brake

And you know VERY VERY VERY well that the steering damper fitted was the WRONG WRONG WRONG one for the bike and therefore had clearance issues lock to lock and the fitting geometry and therefore effective damping force was incorrect. Your supplier / purchaser and fitter at the other end of the world should have been aware of same and I personally pointed out as much to you.
If you are going to play games like this it wont be too long before you need to seek legal counsel to defend yourself in a libel suit. As there will be residual anaesthetic in your system from your horrific ordeal I will overlook this very mischievous outburst.

[Robert Taylor]

yes...A similar system to how the fueling/ignition on MOTOgp bikes work would be good...but would reliy on interacting with the bikes ECU? so would have to be brand specific I suppose?? Havn't other companys gone down the path of electronicly varible suspension on motorcycles before??

Yes, you will see new generation electronic aids on Ohlins suspension units for motorcycles in the not too distant future.
As so often happens electronic aids can often owe more to marketing than true function, and to that end some of the electronically assisted steering dampers on modern sportbikes owe more to marketing.

[Shaun]

And you know VERY VERY VERY well that the steering damper fitted was the WRONG WRONG WRONG one for the bike and therefore had clearance issues lock to lock and the fitting geometry and therefore effective damping force was incorrect. Your supplier / purchaser and fitter at the other end of the world should have been aware of same and I personally pointed out as much to you.
If you are going to play games like this it wont be too long before you need to seek legal counsel to defend yourself in a libel suit. As there will be residual anaesthetic in your system from your horrific ordeal I will overlook this very mischievous outburst.


YES, (1) was fitted badly!!!!! FACT!!!!!!!

The second one was fitted professionally by a Trained mechanic!

The other 2 that have let me down, that you know about! were not fitted badly, they just BROKE-FACT!



Robert, Legal councel, ba hahahahaha :niceone:

[Robert Taylor]

YES, (1) was fitted badly!!!!! FACT!!!!!!!

The second one was fitted professionally by a Trained mechanic!

The other 2 that have let me down, that you know about! were not fitted badly, they just BROKE-FACT!



Robert, Legal councel, ba hahahahaha :niceone:

They were incorrect and you know it and strange how it has happened with yourself who has also been the fitter.

[Shaun]

They were incorrect and you know it and strange how it has happened with yourself who has also been the fitter.



But you sold me those 2 Rob,:eek: guess I must have forgotten, that when you sold them to me, you also told me they were the incorrect ones-:doh: dam, I can be silly, Must be the residue in my system you keep refering to you, speaking of Liabillity!:devil2:

I guess I must be a crap fitter then, as every bike I have ever built, has fallen apart eh- sorry guys, and I must have just fluke built every motorcycle I have ever won a race on in New Zealand over a few years:bleh:

But as I have said on nearly every post on this web site about you and your work, Brilliant, keep it up mate, you are doing yourself proud.

[Robert Taylor]

But you sold me those 2 Rob,:eek: guess I must have forgotten, that when you sold them to me, you also told me they were the incorrect ones-:doh: dam, I can be silly, Must be the residue in my system you keep refering to you, speaking of Liabillity!:devil2:

I guess I must be a crap fitter then, as every bike I have ever built, has fallen apart eh- sorry guys, and I must have just fluke built every motorcycle I have ever won a race on in New Zealand over a few years:bleh:

But as I have said on nearly every post on this web site about you and your work, Brilliant, keep it up mate, you are doing yourself proud.

Yes and given that the fitment on the very latest models is much more critical I recognised the absolute need that the absolute correct dedicated kit must be fitted, despite higher price. That some other end users overseas have chosen to ignore same ( or have gone for a cheaper price as so often occurs here in NZ ) is not a finger that can be pointed at me, I have my house in order and YOU KNOW IT.

I made no reference whatsoever to the subject of building bikes but as you mention it yes you have built some very fast bikes that have won races and championships.

Now go and spend some time with your family instead of trying to ''divide and conquer''

[Shaun]

OK, off to the beach now

[TDC]

I'm personally very interested in the electronically mapped shock that WP are working on, they have a gps system which tells a control unit exactly where the bike is on the track and then via an electronic control valve adjusts the shock accordingly.

I'm not so convinced at this approach.

I feel the real trick would be a shock based on one of the uber trick fluids that change viscosity with electric current and some very fast speed sensing equipment, now that could be fun a shock thats pretty much one size fits all with any response curve you want uploaded via laptop or some such device.

I think the GPS version is like saying we can't get a wide range of wheel control with the existing design, rather than fix it lets just make sure we have the right set or most advantages set of compromises available for each corner.... Just don't really sound like progress to me, but hi tec (read overly complicated) band aid.

If the team you were fighting in a title had this device a radio jammer could be interesting....

[Ocean1]

I feel the real trick would be a shock based on one of the uber trick fluids that change viscosity with electric current and some very fast speed sensing equipment, now that could be fun a shock thats pretty much one size fits all with any response curve you want uploaded via laptop or some such device.
.

Bit early yet I understand. I know a guy who does some very advanced computational fluid dynamics work. Ask him about Electro-Rheostatic fluids and you'd think someone had shat in his Milo. The variables are very difficult to manage, and I mean an order of magnitude more so than "simple" CFD models.

Not only are the numbers tricky, I believe the fluids available pose limitations that'd be hard to live with in a high performance shock. Some ER fluids have response times in the order of 100 msec, which still ain't that quick in terms of a shock movement, and thay need lotsa volts. Not sure how they react to variations in temp either.

Blue sky budget might focus on one of these:

Artificial muscle has been fabricated from naturally occuring long chain pro-teins. Two proteins (actin and myosin), found in biological muscle tissue have been extracted from shellfish and used to produce gels. In muscle tissue, actin and myosin fibers interlock to form a kind of biochemicalratchet. Energy-rich ATP molecules power the attachment, bending, and straightening of themyosin strands. Researchers have extracted actin and myosin proteins from scallops, and used chemical reactions to linkthe molecules together into polymeric gels. When a microscopic piece of actin gel was placed against themyosin gel and immersed in an ATP solution the actin gel sprang into motion at about one thousandth of a millimeter per second.


Carbon nanotubes are very thin and long tubes. Their diameter is only a few nanometers, about the diameter of typical molecules, and they can be up to millimeters in length. Carbon nanotubes increase their length when electrons are pushed into the carbon structure. This effect can be used for electromechanical actuators. The relatively large length change and the high elastic modulus lead to very large forces forcarbon nanotube actuators. A sandwich configuration has been fabricated to demonstrate the use of carbon nanotubes as actuators. The polarization of the sandwich in this actuator can be accomplished using relatively small voltages.

In the meantime, I don't really have a problem with variable porting to control flow. I wonder how one of the faster digital hydraulic flow controls would work for a primary damping valve. With, as you say, a bunch of transducers keeping tabs on related variables, and a clever wee processor in between...

[Robert Taylor]

Bit early yet I understand. I know a guy who does some very advanced computational fluid dynamics work. Ask him about Electro-Rheostatic fluids and you'd think someone had shat in his Milo. The variables are very difficult to manage, and I mean an order of magnitude more so than "simple" CFD models.

Not only are the numbers tricky, I believe the fluids available pose limitations that'd be hard to live with in a high performance shock. Some ER fluids have response times in the order of 100 msec, which still ain't that quick in terms of a shock movement, and thay need lotsa volts. Not sure how they react to variations in temp either.

Blue sky budget might focus on one of these:

Artificial muscle has been fabricated from naturally occuring long chain pro-teins. Two proteins (actin and myosin), found in biological muscle tissue have been extracted from shellfish and used to produce gels. In muscle tissue, actin and myosin fibers interlock to form a kind of biochemicalratchet. Energy-rich ATP molecules power the attachment, bending, and straightening of themyosin strands. Researchers have extracted actin and myosin proteins from scallops, and used chemical reactions to linkthe molecules together into polymeric gels. When a microscopic piece of actin gel was placed against themyosin gel and immersed in an ATP solution the actin gel sprang into motion at about one thousandth of a millimeter per second.


Carbon nanotubes are very thin and long tubes. Their diameter is only a few nanometers, about the diameter of typical molecules, and they can be up to millimeters in length. Carbon nanotubes increase their length when electrons are pushed into the carbon structure. This effect can be used for electromechanical actuators. The relatively large length change and the high elastic modulus lead to very large forces forcarbon nanotube actuators. A sandwich configuration has been fabricated to demonstrate the use of carbon nanotubes as actuators. The polarization of the sandwich in this actuator can be accomplished using relatively small voltages.

In the meantime, I don't really have a problem with variable porting to control flow. I wonder how one of the faster digital hydraulic flow controls would work for a primary damping valve. With, as you say, a bunch of transducers keeping tabs on related variables, and a clever wee processor in between...

Stay posted, Ohlins have been working with shock electronics for some considerable time.

[boomer]

Stay posted, Ohlins have been working with shock electronics for some considerable time.

I thought that was the Germans? :pinch:

[DEATH_INC.]

I'm not so convinced at this approach.

I feel the real trick would be a shock based on one of the uber trick fluids that change viscosity with electric current and some very fast speed sensing equipment, now that could be fun a shock thats pretty much one size fits all with any response curve you want uploaded via laptop or some such device.
I guess the problem with this is as mentioned earlier in this thread, a thicker fluid will really only affect the lower piston speeds, till the shims start to open.....so the changes in damping will be limited for the extra amount of complication....

[HDTboy]

Death,

If you were running a fliud with which you could quickly vary the viscosity, why would you need shims?

If you wanted to keep the damper as simple as possible, you could run a piston with a number of holes, and use the electronics to vary the damping characteristics.
These could then be based on sensor inputs such as swingarm angle, swingarm speed, cycle speed, throttle position, engine revs.
Going a level deeper, one could build a fuzzy logic into the system, so that if it recognised a pattern of a particular movement, followed by another particular movement (Eg: turn 1 at Pukekohe), it could then pre-empt the second movement, and have the damping ready for the bump before it hits. Or another example would be exiting the hairpin on a superbike. Every time when a particular reading of throttle position and revs are met, it could theoretically damp to compensate.

[Robert Taylor]

Death,

If you were running a fliud with which you could quickly vary the viscosity, why would you need shims?

If you wanted to keep the damper as simple as possible, you could run a piston with a number of holes, and use the electronics to vary the damping characteristics.
These could then be based on sensor inputs such as swingarm angle, swingarm speed, cycle speed, throttle position, engine revs.
Going a level deeper, one could build a fuzzy logic into the system, so that if it recognised a pattern of a particular movement, followed by another particular movement (Eg: turn 1 at Pukekohe), it could then pre-empt the second movement, and have the damping ready for the bump before it hits. Or another example would be exiting the hairpin on a superbike. Every time when a particular reading of throttle position and revs are met, it could theoretically damp to compensate.

This is probably an oversimplistic quickfire explanation, but,

Especially small damping holes are progressive by nature.

Whereas bending shim stacks arranged over suitably large ports have some reactance to pressure differential and will respond with more or less lift accordingly, varying the flow area. Therefore they modulate flow better with less progressivity. And there is much more flexibility to tune their characteristic, especially if you have a large number of shims.

[Robert Taylor]

I thought that was the Germans? :pinch:

You know the score Boomer, Great Britain 2, Germany 0. The Swedes are supplying electronics to the Germans but yes there are also some German companies developing this technology.

[Pixie]

If you have a fast enough actuator you can do away with fluidic damping all together.
Bose are on the way to developing a workable system for automotive use:

http://www.bose.com/controller?event=VIEW_STATIC_PAGE_EVENT&url=/learning/project_sound/suspension_components.jsp

An interesting development is that the Bose system is regenerative and feeds power back into the cars electrical system,thus reducing the net power requirements of the suspension (ultimately the power comes from the engine,regardless,but the regeneration improves efficiency).
Add a teraHertz radar system to measure the road surface before the front tyre arrives at the bumps,and you might be approaching perfection in suspension performance.

(yes they are the ones that make the sound systems)

[cowpoos]

You know the score Boomer, Great Britain 2, Germany 0. The Swedes are supplying electronics to the Germans but yes there are also some German companies developing this technology.
germany should have changed coach!!

[Sanx]

Add a teraHertz radar system to measure the road surface before the front tyre arrives at the bumps,and you might be approaching perfection in suspension performance.

Now that is an interesting idea. Instead of setting up the suspension to cope with the bumps and undulations in a particular surface, you have suspension that sets itself up for the road surface it's on at that particular point...

[DEATH_INC.]

Death,

If you were running a fliud with which you could quickly vary the viscosity, why would you need shims?

If you wanted to keep the damper as simple as possible, you could run a piston with a number of holes, and use the electronics to vary the damping characteristics.
These could then be based on sensor inputs such as swingarm angle, swingarm speed, cycle speed, throttle position, engine revs.
Going a level deeper, one could build a fuzzy logic into the system, so that if it recognised a pattern of a particular movement, followed by another particular movement (Eg: turn 1 at Pukekohe), it could then pre-empt the second movement, and have the damping ready for the bump before it hits. Or another example would be exiting the hairpin on a superbike. Every time when a particular reading of throttle position and revs are met, it could theoretically damp to compensate.
Thought of this too, but I think there's still not enough technology out there for this to be viable, at least not yet.....maybe it would be much easier to just vary the damper orifice (s) electronically? Why not just go to full active suspension if your gonna run some complicated electronic setup?
I still believe theres a place for mechanical devices on motorcycles, sometimes they do just work better.....