New Ohlins front end review

[Toot Toot]

Well I will start by letting you know a bit about me.
A lot of you will know me by my old login, I have been around since the inception of KB and would hope I held a little bit of respect. However due to a situation that arose I can no longer use that login, would prefer those that know me not to publicly identify me for now... cheers.

That out of the way.. I am generally a road rider, and while certainly not a racer I do enjoy the occasional track day and would like to think I am "fastish". I have owned quite a number of motorcycles in the past, including some dirt bikes as a teen, then my first road bike was a Kawasaki KR1 two stroke, after blowing that up a few times I bought a Honda CBR250RR. This was a fantastic bike to learn on. After that I moved up to a Suzuki TL1000R, after which I bought an ex-race bike from Shaun Harris. It was a K5 Suzuki GSXR750, it had a lot of bolt on "go better" bits and pieces and quite a bit of internal engine work, never the less I still managed to high side that bike and write it off.
With the insurance money from that bike and a bit from the bank I bought a brand new K8 Suzuki GSXR750, which is my current bike.

I have ridden it for the past 14 months in its absolutely stock standard 'out of the box' settings. I basiclly picked the bike up from the dealer and rode away. It still has its OEM tyres, and has done 7000 kms.
I found the bike a lot of fun, it didnt feel like it had much more power than my K5, but it felt more nimble and lighter. I dont know if that was my imagination though because the specs are not much different between the models. I liked the new look of the bike, Suzuki stylists have done well again. I wanted to steer away from the traditional blue and white, so chose the black and burnt orange.

The other day I got a call from Shaun Harris of Motodynamix asking me if I would like to test some suspension he had. Now I have ridden for quite a few years on the road and track on bikes that are standard and also fully race setup. In my opinion I dont see the point in spending 3 to 4K or more on suspension on a bike like mine that is mainly used on the road and the odd track day. Sure if I was Jimmy McNair I would be using the bike beyond its standard limits and these flash bolt ons would be advantageous.. but not me. But I do know that my bike can be better than it is now in the handling department, but do I want to spend $4k to acheive that?? Not on an $18,000 bike! What if there was some middle ground? This is where Shaun Harris and Robert Taylor from Crown Kiwi Technical (CKT) have come up with a solution.
Motodynamix and Robert are working together to give all of us road riders that want a little more out of our bikes that extra edge...without the price tag.

Essentially the idea is I take my bike to Shaun, who removes my front forks and replaces them with new ones. The "new ones" are on the outside identical to my standard forks i.e. the "outers" are standard.
The internals are where the business is , ohlins internals. I will leave Shaun or Robert to explain that side of it cause I will muck it up.
My standard forks are then whisked away by Shaun to be converted with new inners for the next customer and so on.
So you would only pay for the inside bits and get them fitted. It took Shaun an hour and a half between lots of people talking to him and ciggie breaks to do the job from start to finish. He said, take it for a spin and see what you think.

So we were in west Auckland at Tony Frost Motors (gimme a free trackday for that name), I thought a quick spin out to Piha should do the trick.
Well the first intersection came up and I immediatly noticed a difference! There was no sloppy dive when I braked for the intersection. Hmmm I thought, thats cool.
So anyway I buggered off toward Piha. For those of you that dont know Scenic Drv and Piha Rd it is a combination of fast sweepers into tight 25k corners, both steep uphill and downhill. Some parts are bumpy while others smooth tarmac. A great cross section of New Zealand type roads.
So I set off at a moderate pace, wanting to get a feel for the new front end before pushing it too much. The road was dry and in good condition, and not a lot of traffic. After a few minutes I could see that I could start to push this new front end.
I found I could ride a lot quicker into corners as when I braked the bike didnt dive but seemed to keep its nose up a bit, which gave me confidence to turn in and get on the power early. The front end wasn't "rebounding" back up when releasing the brake lever after heavy braking so I was able to maintain a much smoother line through the corner. So now because the bike wasnt diving and rebounding through the brakes I could brake much harder, later and get on the gas earlier through a corner.
I was still avoiding those horrible ruts or ripples that are in the tyre tracks in some of the corners though. They seem to be only on right handers and in the right hand tyre track, I think they are caused by trucks on hot days when the tar is at its softest. Either way I always avoid them, meaning often making you take a less than ideal line through the corner, or you ride through them causing the bike to buck and bounce through the corner, unsettling you for the next corner, even being the cause of many crashes.
I thought I would tackle these bumps and was pleasently surprised. Although I could obviously feel the vibrations through the bars the bike didn't seem to move much at all, it stayed planted on the road and the front didnt skip about.
The next noticable difference was changing direction through a quick series of corners (esses), the bike didnt seem as if it was changing direction at all if that makes any sense, the bike was leaning and then quickly flipping over for the following corner without any up and down movement of the front, just like I was travelling in a straight line??
This meant that I had to put in less input to the change of direction, resulting in being less tired, therefore keeping my concentration levels up. I wasnt fighting the bike to change direction, it was just doing it.

I brought the bike back to Shaun and was surprised to see that the front suspension had actually used MORE travel....not less... as I had supposed, cos there was no dive. He explained that the bike was now using more of its usable travel and actually work properly, but done it slower so I didn't notice the extra travel... again I will let Shaun explain this cos I dont understand it.
Overall I am very pleased with the new front end. Next is a different rear.. looks like a Penske shock, so watch this space for more action!

Cheers Shaun and Robert.

[Tony.OK]

Sounds like someones been converted........................yep it may seem expensive at first, the beauty of alot of it is that it can also be carried on to the next bike too, saving that initial outlay being wasted if you sell.
Nice write up:niceone:

[Kiwi Graham]

Going down the same route on my R1, money well spent in my opinion. Good write up.

[Cajun]

nice write up mate, will wait to hear Robert or Shaun to explain what they done.

[The Stranger]

A lot of you will know me by my old login, I have been around since the inception of KB and would hope I held a little bit of respect. However due to a situation that arose I can no longer use that login, would prefer those that know me not to publicly identify me for now... cheers.



Ok Winja, my lips are sealed.

[cowpoos]

after which I bought an ex-race bike from Shaun Harris. It was a K5 Suzuki GSXR750, it had a lot of bolt on "go better" bits and pieces and quite a bit of internal engine work, never the less I still managed to high side that bike and write it off.


oh...maybe thats why my one was so slow on the track??? ;)

[AllanB]

So how muchly?

Nice colours on the GSXR by the way.

[Toot Toot]

oh...maybe thats why my one was so slow on the track??? ;)

No that was the rider

[dipshit]

hmmmm... interesting.

Thanks for giving your impression of them.

[Toot Toot]

So how muchly?

Nice colours on the GSXR by the way.
Cheers man. I will get Shaun to talk prices I would hate to say the wrong thing.

[Sensei]

How much then ???

[cowpoos]

No that was the rider
oh...sorry I was mistaken!!

what was that story about your highside?? boomer where are you??

[boomer]

oh...maybe thats why my one was so slow on the track??? ;)


No that was the rider


oh...sorry I was mistaken!!

what was that story about your highside?? boomer where are you??

i'm here just in from the pub where i got my ass handed to me at poker :(

i read this post with interest earlier, and just txt'd teh fooker now to see if hes free tomorrow nite.

i kept my gob shut , but i did take note of 3 things..



he says hes fast
he says teh bike was tricked out
he says the bike high sided him


Now if i were a lawyer i'd have toot toot serving time for purgery about now.. but as i know the coont i'll say NICE WRITE UP WINJA !


lol Poos.. shall we just sit in the corner and giggle like school girls??!

[boomer]

How much then ???

2 and 10 for u , u old fookah !

[Toot Toot]

he says hes fast
he says teh bike was tricked out
he says the bike high sided him
I said fastish, clearly not as fast as you Boomer.

It had a few modifications

I high sided/it high sided me, whatever, I crashed.

[cowpoos]

lol Poos.. shall we just sit in the corner and giggle like school girls??!

I already am!!! lmfao!! :done:

[cowpoos]

[/LIST]I said fastish, clearly not as fast as you Boomer.

It had a few modifications

I high sided/it high sided me, whatever, I crashed.
that sounds simple...is there more?

[Toot Toot]

Can we keep this thread on topic please, if you wanna bash me then do it in all the other threads where I can fight ya's!

Boomer wont change his poker time tommorow so that I can go..... dont want another ass wooping son?

[Pussy]

To what extent have the forks been revalved, G? Resprung too?

[Sensei]

2 and 10 for u , u old fookah !

Fuck just sent $1200 doing the Mid valve bending shim stack mod & rebuilding my Ohlins Forks :doh:

[Toot Toot]

I know it has mid-valve bending shim stack and re-sprung, oil, revalve etc. Dont quote me but I'm pretty certain this is all below $1000.
I text shaun but he not replied yet.

[boomer]

I already am!!! lmfao!! :done:

im pissed and thats soooo funny !



that sounds simple...is there more?

lol.. u reckon there's more.. Moooore!!!!!!??!?!?! Hey Toot Toot.. is there more.>>>>????



Can we keep this thread on topic please, if you wanna bash me then do it in all the other threads where I can fight ya's!

Boomer wont change his poker time tommorow so that I can go..... dont want another ass wooping son?

you look sick, u sure you're gonna go to work tomorrow au?!

and yeah i need lessons in poker liek i need lessons in riding a bike fast :bleh:


call me :mobile: and come over !!!


( this shsi is just like the old days..!! )

[Toot Toot]

that sounds simple...is there more?

Will tell you over a Tui sometime sunshine :shifty:

[Shaun]

Great Toot Toot, Very glad you enjoyed it! I am just about to do my morning things with my Daughter for school etc, so will get back on here later on, and explain all a bit more, UNLESS Robert gets on here first with a thourough tec break down on what has been done here.

[Robert Taylor]

Great Toot Toot, Very glad you enjoyed it! I am just about to do my morning things with my Daughter for school etc, so will get back on here later on, and explain all a bit more, UNLESS Robert gets on here first with a thourough tec break down on what has been done here.

Sorry thats going to have to wait until tonight / tommorrow as a very busy day is ensuing.

[Robert Taylor]

Fuck just sent $1200 doing the Mid valve bending shim stack mod & rebuilding my Ohlins Forks :doh:

60% or so of the content of that bill was replacement of a very large part of the componentry that was cracked, much less of it was a piston upgrade. Just so no-one misunderstands....

[Patch]

A lot of you will know me by my old login, I have been around since the inception of KB and would hope I held a little bit of respect.
maybe, maybe not - but wot sort of gay fookn name is toot toot :laugh:

U been watching chitty chitty bang bang??

[Shaun Harris]

Going down the same route on my R1, money well spent in my opinion. Good write up.




I will be bringing your gear back up to Auckland on next Monday dude, you know where they will be.

I think Frosty Likes BEER

[Shaun Harris]

Sorry thats going to have to wait until tonight / tommorrow as a very busy day is ensuing.




Have you ever tried actually working faster:2guns:

[Kiwi Graham]

I will be bringing your gear back up to Auckland on next Monday dude, you know where they will be.

I think Frosty Likes BEER

Cheers buddy, offers still on for a place to kip if you want. I'll sort the Frostmyster!

[Toot Toot]

maybe, maybe not - but wot sort of gay fookn name is toot toot :laugh:

U been watching chitty chitty bang bang??

Yeah its pretty gay alright, but I had to think of a name quick.
It is what my boy used to call the bike as when I would come home I would toot the horn so he could press the garage door opener for me.
He would say, "Here's toot toot". So that's what I'm called.

What sort of a name is "Patch" anyway. Sound like the Golden books My first little puppy... his name is patch.

[Sensei]

60% or so of the content of that bill was replacement of a very large part of the componentry that was cracked, much less of it was a piston upgrade. Just so no-one misunderstands....

Wasn't ment as a dig at your price Robert I was very happy with that , just to make sure that is clear to you , Will talk to you about how the new mod has changed my front forks .

[Robert Taylor]

Thanks a whole heap Toot Toot for the very comprehensive report. Technically this is not an Ohlins upgrade even though these forks sport our very sexy CKT / Ohlins logo. We did though use Ohlins shims but on the stock piston and filled with Ohlins oil that has very stable flow properties at cold temps.
The late model GSXR600/750 series has very weak rebound damping and that manifests itself as a ''flighty'' front end on sudden flip flop ( side to side ) direction changes, especially over the crest of a rise etc. It also means that when in transition mid corner and off the brakes the front end tries to stand up. We cure that totally with a new rebound stack that we both developed on our dyno and also with road and track tests. I guess we can also indirectly thank Ohlins because we have some very proven Ohlins rebound and compression curves on our dyno database and we emulate those as closely as possible with the work we do revalving oem cartridges or when fitting Race Tech upgrade components. It wont turn the suspension into Ohlins but makes a huge bang for buck improvement nonetheless.
The ''increase'' in fork travel before it reaches the bottom is accounted for by the fact we disarm approximately 80% of the bottoming control hydraulic stop device, which happens too early and too aggressively. This is a common issue on many sportbikes, if we end up with a second tier class in 600 sports production that only allows spring changes this is one issue where if not modified it WILL cause the odd crash or two, on its own account. That is because the compression damping force suddenly goes through the roof when the hydraulic piston stop comes into play, 25mm or so before ''full closed'' distance. Not ideal when you are peeled into a corner close to the limits of grip and suddenly the suspension locks up. I bet thats one that a lot of people havent thought of.
This modification / upgrade runs out at retail $479 gst inclusive and is available through Shaun at Motodynamix. Shaun is largely acting as our ''man at the coalface'' because he is more geared up to being constantly out in the field than we can be. Moreover, as an extremely successful road racer ( including Isle of man winner ) and an extremely articulate test rider ( used by me over many years ) he is the ideal guy to assist in helping optimising the settings once reinstalled in the bike.
Currently also we are developing revalve specs for standard ( oem ) rear shocks, again drawing on ''Ohlins damping profile''.

[Robert Taylor]

Part 2! There are a lot of misconceptions in this game and also a bit of skulduggery going on. As follows;

1) As pointed out by an overseas suspension contributor some time ago many people are fooled into thinking that their oem suspension woes can be fixed with a few external clicker and spring preload changes. Ride into the shop, have it adjusted with those clickers ( that many think have an adjustment range 2 miles wide ), wind up the preload and ride away like being in a land of milk and honey. 9 times out of 10 that just isnt so and so often the riders are ''conditioned'' by magazine tests or manufacturers pr hype thats economical with the truth.

2) In the case of the GSXR750 with the weak rebound issue the instinct of the rider / tuner is to keep winding in the external rebound clicker at the top of the forks. So often we have found the adjuster to be only 1/8th of a turn out or less. As this regulates bypass flow through the centre of the shaft it ''cross talks'' so also affects compression flow. It only fixes a small percentage of the issue because fundamentally the shim stack opening pressure is too weak. CLICKERS ONLY ADJUST INTERNAL BYPASS FLOW AND THE RANGE OF EFFECTIVE ADJUSTMENT IS IN FACT QUITE NARROW. If there is an internal shim stack calibration or piston isuue no amount of external adjustment is going to fix the problem!!

BUT ALSO, on that GSXR fork ( which has a bending shim stack midvalve ) if you wind in the rebound clicker too far ( even 1/2 turn out is very marginal ) the fork has huge hysterisis ( cavitation ) on flow reversal from compression ( bump) to rebound strokes. It cannot ''pressure balance'' fast enough on flow reversal from one side of the rebound piston to the other. Simply put, thats a delay in damping response as for a few milliseconds there are vacuum pockets in the oil and that reduces control and rider feel. There are probably more than a few othetrwise unexplained crashes that can be attributed to that.

3) Ist world European and North American countries have their share of bumpy roads but they also have a much much higher ratio of relatively smooth A grade roads. Here in our own ''shaky isles'' we have a much much higher ratio of bumpy roads, potholes, bad surface condition and ''g out'' circumstances. Because of that we are attentive to suspension issues that in the aforementioned countries are relatively minor. We are for example selling more and more Ohlins shocks for Harleys as they deliver ride height control but also deliver square edge bump compliance that is light years better. Most of the US sourced aftermarket shocks for Harleys deliver a dissappointing level of improvement because they are only made to ''ride down the boulevard'', as it were. You have to read between the lines.

[Robert Taylor]

Part 3, more misconceptions;

4) '' Im not fast enough for an Ohlins, theyre only for racers'' Absolutely 100% not true. Most of our customers are in fact ordinary everyday road riders who want much better control ( and often tyre life ) but predominantly also want suspension that is actually going to comfortably absorb bumps without a visit to the chiropractor in later life.

5) We are not only about Ohlins!!!

Level 1; Service / revalve oem suspension. Much like the GSXR fork example. Relatively low cost, great bang for buck.

Level 2; Upspec oem suspension with Race Tech components. Respring, re-piston etc. We are the biggest Race Tech centre in the country and specialise in road / road race ( assisted by what we have learnt with our dyno and on road and track ) We are also doing lots of dirtbikes and race car stuff right through to the very highest levels.

Level 3; Upspec with Ohlins suspension.

WE SERVICE / REPAIR / UPSPEC MOST SUSPENSION SYSTEMS AND ALWAYS PROVIDE A COST MENU AFTER INSPECTION AND PRIOR TO PROCEEDING FURTHER

6) ''They are only interested in helping the top riders and they will cost you an arm and a leg'' ( Mischievously perpetuated by competitors trying to seek business )
In fact we will help anyone that asks and many readers of this diatribe will testify to same. Weve lost count of the number of people we have helped at absolutely no charge.
FURTHER, we are always very mindful of costs and the riders budget.

7) And this is the most insidious recent example.........we were a touch late to the first round of VMCC at Taupo recently and a competitor brazenly told one of our customers '' they are not coming''. We know what goes on!

WE WILL HELP AND OFFER ADVICE TO ANYONE THAT ASKS.

[Shaun]

Thanks for the thorough tech brake down on these fork specs, and other options open for people. I see this set up spec as very very good value for $

[dipshit]

I see this set up spec as very very good value for $

Indeed. I may have to take a ride up to New Plymouth one day.

[Shaun Harris]

Indeed. I may have to take a ride up to New Plymouth one day.


It will be worh it! Pussy- Toot Toot And many more, that have all been a part of the the learning process:soon: Are very happy riders with this product, " IT IS NOT THE BEST PRODUCT FOR $ $ $, BUT IT WORKS:second:

[Pussy]

It will be worh it! Pussy- Toot Toot And many more, that have all been a part of the the learning process:soon: Are very happy riders with this product, " IT IS NOT THE BEST PRODUCT FOR $ $ $, BUT IT WORKS:second:

Slight correction, Shaun.... it's Gassit Girl's bike that has the OEM rebound mod.
She is very happy with it (in fact, I think it was her bike that had the first one).
The stock Showa forks are pretty good on these bikes... apart from the weak high speed rebound characteristic. This mod sorts that problem perfectly.

We also tried the Racetech G2R cartridges for a few weeks in Annie's bike, they were bloody good, too... but of course come at a higher price

[NZsarge]

This modification / upgrade runs out at retail $479 gst inclusive
Very interesting, quite a bit cheaper than I thought it might be...

Currently also we are developing revalve specs for standard ( oem ) rear shocks, again drawing on ''Ohlins damping profile''.

Hmmm, again, very interesting.

[Robert Taylor]

Hmmm, again, very interesting.

Well thats good that its cheaper than people percieve!

[NZsarge]

Well thats good that its cheaper than people percieve!

I guess so, then again if people did'nt perceive the price as high as I did you'd probably be over run with business (that's if you are'nt already), btw, I only perceived it be more expensive than what it cost Toot toot because I based my ideas on a previous costing you gave me on my FZ1 which unfortunately I could not afford.
I realize that's not fair but it's what I was using as a guide and there by putting myself off asking you what it was going to cost me if I wanted to do my new bike, plus I really did'nt want to get you doing anything like costing things until I was pretty serious about spending hard earned, I was going to ask you if it would be possible to rebuild my rear shock to a better spec along with a re-spring too so all-in-all it look more positive that I can get something done about the shocking forks on my bike (ZX14 Probably ok for most but most definitely not me!) at least and perhaps the shock to at some point.

[SPman]

Indeed. I may have to take a ride up to New Plymouth one day.
Pity we can't do that from Perth!

Anyone know who does a similar service over here?

[Pussy]

The other two things we did to Gassit Girl's 750 were:
Respring it for her weight (linear Ohlins springs)

Used Ohlins 15cst oil (the stock oil looks like treacle)

Respringing adds to the cost a bit, but that is outweighed by having the bike set up "just so"

[Robert Taylor]

I guess so, then again if people did'nt perceive the price as high as I did you'd probably be over run with business (that's if you are'nt already), btw, I only perceived it be more expensive than what it cost Toot toot because I based my ideas on a previous costing you gave me on my FZ1 which unfortunately I could not afford.
I realize that's not fair but it's what I was using as a guide and there by putting myself off asking you what it was going to cost me if I wanted to do my new bike, plus I really did'nt want to get you doing anything like costing things until I was pretty serious about spending hard earned, I was going to ask you if it would be possible to rebuild my rear shock to a better spec along with a re-spring too so all-in-all it look more positive that I can get something done about the shocking forks on my bike (ZX14 Probably ok for most but most definitely not me!) at least and perhaps the shock to at some point.

Not all jobs are ''tarred with the same brush''. The GSXR forks are a very good production fork with one glaring issue that we can sort out at a good price. Of course, if the rider weight is outside of the average range they will also require springs, which of course adds to the cost.
Conversely the FZ1 forks are like most naked bikes starting from a lower base line and in this case are a particularly bad example. The pistons are little better than check plates. To get these things to work properly at all they need rebound pistons, rebound piston holders, compression pistons, compression piston holders, springs, spring guides, spring preload spacers and a bit of clever machining. That unavoidably is a dollar exercise.

[NZsarge]

Not all jobs are ''tarred with the same brush''. The GSXR forks are a very good production fork with one glaring issue that we can sort out at a good price. Of course, if the rider weight is outside of the average range they will also require springs, which of course adds to the cost.
Conversely the FZ1 forks are like most naked bikes starting from a lower base line and in this case are a particularly bad example. The pistons are little better than check plates. To get these things to work properly at all they need rebound pistons, rebound piston holders, compression pistons, compression piston holders, springs, spring guides, spring preload spacers and a bit of clever machining. That unavoidably is a dollar exercise.

Yeah, I remember you saying the forks on the Fazer were a bigger job than perhaps normal, here's hoping the ZX14's forks are'nt as bad to upgrade, cheers.

[JD Racing]

Thanks a whole heap Toot Toot for the very comprehensive report. Technically this is not an Ohlins upgrade even though these forks sport our very sexy CKT / Ohlins logo. We did though use Ohlins shims but on the stock piston and filled with Ohlins oil that has very stable flow properties at cold temps.
The late model GSXR600/750 series has very weak rebound damping and that manifests itself as a ''flighty'' front end on sudden flip flop ( side to side ) direction changes, especially over the crest of a rise etc. It also means that when in transition mid corner and off the brakes the front end tries to stand up. We cure that totally with a new rebound stack that we both developed on our dyno and also with road and track tests. I guess we can also indirectly thank Ohlins because we have some very proven Ohlins rebound and compression curves on our dyno database and we emulate those as closely as possible with the work we do revalving oem cartridges or when fitting Race Tech upgrade components. It wont turn the suspension into Ohlins but makes a huge bang for buck improvement nonetheless.
The ''increase'' in fork travel before it reaches the bottom is accounted for by the fact we disarm approximately 80% of the bottoming control hydraulic stop device, which happens too early and too aggressively. This is a common issue on many sportbikes, if we end up with a second tier class in 600 sports production that only allows spring changes this is one issue where if not modified it WILL cause the odd crash or two, on its own account. That is because the compression damping force suddenly goes through the roof when the hydraulic piston stop comes into play, 25mm or so before ''full closed'' distance. Not ideal when you are peeled into a corner close to the limits of grip and suddenly the suspension locks up. I bet thats one that a lot of people havent thought of.
This modification / upgrade runs out at retail $479 gst inclusive and is available through Shaun at Motodynamix. Shaun is largely acting as our ''man at the coalface'' because he is more geared up to being constantly out in the field than we can be. Moreover, as an extremely successful road racer ( including Isle of man winner ) and an extremely articulate test rider ( used by me over many years ) he is the ideal guy to assist in helping optimising the settings once reinstalled in the bike.
Currently also we are developing revalve specs for standard ( oem ) rear shocks, again drawing on ''Ohlins damping profile''.

An interesting post considering your statement in another thread:

8% or more of the world economy is piracy. And in NZ making a fair and reasonable profit is something that many frown upon. Having respect for intellectual property is also something that many dont take seriously.

I wonder where the intelectual property lies is it in the components that generate the damping curve or the damping curve itself?

[Robert Taylor]

An interesting post considering your statement in another thread:

8% or more of the world economy is piracy. And in NZ making a fair and reasonable profit is something that many frown upon. Having respect for intellectual property is also something that many dont take seriously.

I wonder where the intelectual property lies is it in the components that generate the damping curve or the damping curve itself?

Yes fair call but there is a distinction between what is a blatant ripoff. What I resent is blatant piracy that takes food out of the mouths of the employees of companies that spent the development dollars and hard yards. Seems we live in a dog eat dog world, does it not?

[Cajun]

hey Robert

what year GSXR does the above fix apply to?

[Robert Taylor]

hey Robert

what year GSXR does the above fix apply to?

06 on, its a while since I have looked at 05, maybe also.

[Pussy]

It's not as though you're making Ohlins pistons etc, RT!
Since when was what a rider wants as a suspension characteristic an intellectual property?
Do Bridgestone tyres not rotate like Dunlops?

[JD Racing]

Pussy,
Personally I want more from my tyres than to just go round otherwise I'd ride on the rims.

I think the argument surrounding plagerism is an interesting one, which came first the Ohlins compression piston or the HMAS compression piston? I wonder where the influence for all of K-Tech's products came from??? Sweden maybe???

Where would two stroke development be if Suzuki hadn't received all of Walter Kadens work via Ernst Degner?

[cowpoos]

Pussy,
Personally I want more from my tyres than to just go round otherwise I'd ride on the rims.

I think the argument surrounding plagerism is an interesting one, which came first the Ohlins compression piston or the HMAS compression piston? I wonder where the influence for all of K-Tech's products came from??? Sweden maybe???

Where would two stroke development be if Suzuki hadn't received all of Walter Kadens work via Ernst Degner?
we could use many examples to discuss the evolution of the internal compustion engine...but the key is evolution..

Off topic...have you had a play with those big piston forks yet JD??

[JD Racing]

I could directly copy an Ohlins piston, and I fit it with all 0.1 shims, I've copied the hardware but don't get the damping curve, if I take a HMAS piston and fit it with Ohlins valving, who did I rip off Honda/Showa or Ohlins?

The big piston forks...all marketing, no action.

[Pussy]

Fair enough comment...
But what about when I come along and ask for a damping/working characteristic of a known quantity, and request my suspension perform as such?
To me, that's someone using their knowledge to acquire a satisfactory outcome

[cowpoos]

I could directly copy an Ohlins piston, and I fit it with all 0.1 shims, I've copied the hardware but don't get the damping curve, if I take a HMAS piston and fit it with Ohlins valving, who did I rip off Honda/Showa or Ohlins?


Imitation is the highest for of flattery, is it not??
I know your point...but essentially...unless the piece of hardware is a revolution/revelation and a well discovered patent is accepted or the valving spec not easily discovered by another tuner...or not copyrighted well...its fair game...I'm not supporting Robert Opinion nor yours...its just how things are...and have you never tried to imitate damping curves before??




The big piston forks...all marketing, no action.

Are they hard chromed the inside of the stanchion tube??
Have you ever come across Showa Factory big piston forks [race kit]??

[Robert Taylor]

Pussy,
Personally I want more from my tyres than to just go round otherwise I'd ride on the rims.

I think the argument surrounding plagerism is an interesting one, which came first the Ohlins compression piston or the HMAS compression piston? I wonder where the influence for all of K-Tech's products came from??? Sweden maybe???

Where would two stroke development be if Suzuki hadn't received all of Walter Kadens work via Ernst Degner?

A certain Ohlins distributor in the Northern hemisphere has a financial interest in K-Tech and it appears to be tolerated ''by the grace of god''. K-Tech make some really nice stuff.
The Traxxion 20mm compression piston is a marriage of an old 20mm preloading type Ohlins superbike piston but with Race Tech style big ports.
We had some pistons made that resembled an earlier Ohlins design that was out of production, but we politely asked Ohlins first if that was okay.

And so on, funny world.....

[Robert Taylor]

I could directly copy an Ohlins piston, and I fit it with all 0.1 shims, I've copied the hardware but don't get the damping curve, if I take a HMAS piston and fit it with Ohlins valving, who did I rip off Honda/Showa or Ohlins?

The big piston forks...all marketing, no action.

I hear what you are saying.

Im sincerely interested in your ( not too lengthy ) appraisal and comments re the BPF forks as Im at this point skeptical about them.

[cowpoos]

Im sincerely interested in your ( not too lengthy ) appraisal and comments re the BPF forks as Im at this point skeptical about them.

Ditto...but I don't mind lengthy. as apparently they are in some serious top machinery now and in the past we while..the factory versions that is...

[Pussy]

Hey, Poos...
There is a very good article in the April 2009 Superbike magazine on the BPF.
Written by Ken Summerton, who apparently knows what he's talking about. He explains a few shortcomings of the "garden variety" BPF found in the bikes we can buy off the floor.




Don't bother hitting Nicksta up to borrow her copy... I've still got it!

[cowpoos]

Hey, Poos...
There is a very good article in the April 2009 Superbike magazine on the BPF.
Written by Ken Summerton, who apparently knows what he's talking about. He explains a few shortcomings of the "garden variety" BPF found in the bikes we can buy off the floor.




Don't bother hitting Nicksta up to borrow her copy... I've still got it!
got a scanner??

[Pussy]

:yes: <I have got a scanner>

[DrZeeple]

We had some pistons made that resembled an earlier Ohlins design that was out of production, but we politely asked Ohlins first if that was okay.

Wouldn't be OP1515-01 pistons would it? I still have some sitting in my parts bin - just like Traxxion's and Penske VDP's, just that these days I never really see anywhere I want to use them anymore! (actually, only one or 2 places I would use a bath-tub piston nowadays, now that I think about it like...)

I follow these threads with some delight from over in Oz/UK or wherever I be - it is always nice to see discussion about suspension, and if only I had RT's way with words; but sadly not... :laugh:

So, greetings all and nice to make your acquaintance!

Z

[JD Racing]

No special finish on the insides of the tube, the rest is the usual mass produced build quality. I can't believe they resemble anything used on the factory bikes.

The rebound adjusts by a normal needle, the compression adjusts the preload on a spring acting on the compression stack, not a particularly wide range of adjustment. The preload works via a ramp arrangement at the bottom of the fork.

Riders who've used them as standard say they ride very high in the stroke on turn in. Personally I've not played with the valving, 20 & 25mm cartridges have been about for over 10 years and are well down their development path improving all the time, kits drop straight in.
I already have enough on with the 20 and 25mm, the 30mm for the new R1 is coming on well, I don't want to dilute what I'm doing with those chasing a set up on the big piston.

[The Stranger]

we could use many examples to discuss the evolution of the internal compustion engine...but the key is evolution..


Very very few haven't stood on the shoulders of giants in their development of a product or service. How then does someone else standing on their shoulders become wrong.

Another issue I have with regard to protection of an idea is this. Why, by shear dint of the fact one were born first give one a right to claim an idea.
The patenting of the human genome for example or the one click check out patent as developed by Amazon.com

[Robert Taylor]

Wouldn't be OP1515-01 pistons would it? I still have some sitting in my parts bin - just like Traxxion's and Penske VDP's, just that these days I never really see anywhere I want to use them anymore! (actually, only one or 2 places I would use a bath-tub piston nowadays, now that I think about it like...)

I follow these threads with some delight from over in Oz/UK or wherever I be - it is always nice to see discussion about suspension, and if only I had RT's way with words; but sadly not... :laugh:

So, greetings all and nice to make your acquaintance!

Z

Indeed! But now reduntant in my world as well. Much more emphasis on ''mid valve'' rebound pistons.

[Robert Taylor]

No special finish on the insides of the tube, the rest is the usual mass produced build quality. I can't believe they resemble anything used on the factory bikes.

The rebound adjusts by a normal needle, the compression adjusts the preload on a spring acting on the compression stack, not a particularly wide range of adjustment. The preload works via a ramp arrangement at the bottom of the fork.

Riders who've used them as standard say they ride very high in the stroke on turn in. Personally I've not played with the valving, 20 & 25mm cartridges have been about for over 10 years and are well down their development path improving all the time, kits drop straight in.
I already have enough on with the 20 and 25mm, the 30mm for the new R1 is coming on well, I don't want to dilute what I'm doing with those chasing a set up on the big piston.
Cheers for that, am stripping my first set very soon and Id already heard that the adjustment range is very poor.
I like the idea of 30mm cartridges and have a feeling we may see some in the future. Ohlins already have the pistons by virtue of those they have made for the 09 R1.

[Shaun]

tell me boys, why did Whitepower STOP making a Big Piston fork set up?

[cowpoos]

tell me boys, why did Whitepower STOP making a Big Piston fork set up?

whitepower 4054 forks I think your talking about... have a nosey at the picture I have posted.

[cowpoos]

whitepower 4054 forks I think your talking about... have a nosey at the picture I have posted.
you have to right click and open image in new window...then one left click to enlarge image to read it.

[Robert Taylor]

tell me boys, why did Whitepower STOP making a Big Piston fork set up?

I think because they were struggling with it, that continued development would look to be very protracted and ironically cartridges were coming into vogue.
In fairness on the racetrack Showa seem to have their works level stuff working pretty good, but it is not at all the ''big leap forward'' Team Rockstar Suzuki ( Mat Mladin ) in the States ditched that stuff out of their forks and fitted cartridges

It always amazes me how magazine testers ''run away with themselves'' and people believe all the hype. There is quite a differentiation between the PR fantasy world and the reality of working at the coal face and being familiar with the issues. Every technology has issues / limitations.

[JD Racing]

I suppose it's all a progression of the bending shim stack midvalve in that the manufacturers are now metering solely the swept volume where previously it was a combination of swept and displaced volume. Cartridge pressure is now pretty much out of the equation it's now all volumetric flow rate, with the Showa version tuning the air gap will also be limited as too low an oil level will cause problems with oil volume in the chamber.

I'm not a big fan of all this reduced tuning ability, being able to tune the rod displacement and swept volume gives you far more to work with, we now have two systems working at opposite ends of the spectrum, Ohlins say swept volume is history it's all about displaced volume, Showa say displaced volume is history it's all about swept volume, me being an old caveman think the old fashioned combination of the two is still the best way.

[Robert Taylor]

I suppose it's all a progression of the bending shim stack midvalve in that the manufacturers are now metering solely the swept volume where previously it was a combination of swept and displaced volume. Cartridge pressure is now pretty much out of the equation it's now all volumetric flow rate, with the Showa version tuning the air gap will also be limited as too low an oil level will cause problems with oil volume in the chamber.

I'm not a big fan of all this reduced tuning ability, being able to tune the rod displacement and swept volume gives you far more to work with, we now have two systems working at opposite ends of the spectrum, Ohlins say swept volume is history it's all about displaced volume, Showa say displaced volume is history it's all about swept volume, me being an old caveman think the old fashioned combination of the two is still the best way.

Im a fan of any system that has much less risk of cavitation and as you well realise many systems are on a knife edge re that.

[Shaun]

Im a fan of any system that has much less risk of cavitation and as you well realise many systems are on a knife edge re that.



So converting forks to work seperateky ie left leg Rebound

Right leg compression

This would illiminate any cavitation/lock up/confusement of what is doing what and when

Flow has always been what i have asked you for over the years robert when i did ride, ( And we did win more races than we lost) and the way i understand the big piston to work, would allow more flow of oil, before hitting the shim stack, with NO cavitation?

I am going to have to start doing just test development riding again I think, I can see some fun coming in the new worldThanks for your input JD

[Robert Taylor]

So converting forks to work seperateky ie left leg Rebound

Right leg compression

This would illiminate any cavitation/lock up/confusement of what is doing what and when

Flow has always been what i have asked you for over the years robert when i did ride, ( And we did win more races than we lost) and the way i understand the big piston to work, would allow more flow of oil, before hitting the shim stack, with NO cavitation?

I am going to have to start doing just test development riding again I think, I can see some fun coming in the new worldThanks for your input JD

Stand corrected sir! Left leg compression, right leg rebound and yes indeed big benefits especially in damping response time.
Yes it is fun! And I concur, thanks JD.

[Shaun]

Stand corrected sir! Left leg compression, right leg rebound and yes indeed big benefits especially in damping response time.
Yes it is fun! And I concur, thanks JD.



Hey, I was standing when i said that!:Punk:

Keeping the R and the R together may save some confusement perhaps:doh:

[cowpoos]

ummm...yeah on the cavitation issuse...why hasn't someone though of having a separate air canister away from the forks...so more oil can be used in the forks...reducing the risk of cavitation?? cheaper that pressured gas!

another question...has anyone tried modern MX forks [obviously rebuilt ones] on a road race bike? larger rod,piston in the cartridge would displace fluid faster?? stiffer,etc??

[Shaun]

ummm...yeah on the cavitation issuse...why hasn't someone though of having a separate air canister away from the forks...so more oil can be used in the forks...reducing the risk of cavitation?? cheaper that pressured gas!

another question...has anyone tried modern MX forks [obviously rebuilt ones] on a road race bike? larger rod,piston in the cartridge would displace fluid faster?? stiffer,etc??

Q1


Cavitation is caused by the change over point from compression to rebound, ie, the system is not ready to be going up or down, it is like US, confused!

That is why the left and right leg need to be seperated into there own depts, so the reaction/action is more instant/controlled

just like on the ohlins ttx realy, Twin Tube!



I think?

But I am just an old rider, CKT and JD will awnser this fully I am sure

[cowpoos]

oh...I thought cavitation is the mixing of air and oil...which causes the oil to loose its compressive qualities...and making damping less predictive.

[Tony.OK]

oh...I thought cavitation is the mixing of air and oil...which causes the oil to loose its compressive qualities...and making damping less predictive.

Ahhh me too......................so by having the comp/reb in different legs, does that introduce any negative forces such as the forks trying to twist in the triples because they are doing different things?
Or does each leg cancel the other by being neutral when one fork is doing its specific damping?


This threads turned into a goodie:Punk:

[cowpoos]

I would expect the forks to work as one unit once bolted together...but there are alsorts of twisting forces at play...so I'm probally wrong??

[FROSTY]

hey guys maybee I'm wrong but I think theres a strong argument for suspension with limited adjustability for road riders.
Sorta set it (*to suit the riders weight and style) and forget it.

[Robert Taylor]

Q1


Cavitation is caused by the change over point from compression to rebound, ie, the system is not ready to be going up or down, it is like US, confused!

That is why the left and right leg need to be seperated into there own depts, so the reaction/action is more instant/controlled

just like on the ohlins ttx realy, Twin Tube!



I think?

But I am just an old rider, CKT and JD will awnser this fully I am sure

Stop standing on your head, my typing fingers are arthritic........

[Robert Taylor]

hey guys maybee I'm wrong but I think theres a strong argument for suspension with limited adjustability for road riders.
Sorta set it (*to suit the riders weight and style) and forget it.

Yes I hear what you are saying. Having more adjustments means you can also make it really bad!

[Robert Taylor]

Ahhh me too......................so by having the comp/reb in different legs, does that introduce any negative forces such as the forks trying to twist in the triples because they are doing different things?
Or does each leg cancel the other by being neutral when one fork is doing its specific damping?


This threads turned into a goodie:Punk:

Axle clamping area is largely ''ample''

[Kickaha]

Stand corrected sir! Left leg compression, right leg rebound .

Wasn't that what Marzocchi did with the M1R forks?

[Shaun Harris]

oh...I thought cavitation is the mixing of air and oil...which causes the oil to loose its compressive qualities...and making damping less predictive.

Tech YES, BUT what has caused this, is the fact that comression stroke and rebound stroke cross over in the OIL/gas circuit, hense becoming confused, and not knowing what to do.

RE your post about an air circuit, I do not think an air circuit would be a good move, imaging the H20 being introduced into the oil circut? if things are bad now, try riding on Air bubbles

it would be

you got mE, you got me not, you got me, you got me not bla bla bla crash

lUCKILY I am only a test rider now eh, and NOT the technician doing all the internal mods

[JD Racing]

Cavitation is only one aspect that has to be taken account of in the whole system, the few that I've seen that have cavitated have been poorly thought out aftermarket systems, by building a system that builds cartridge pressure rapidly it can be avoided.

Cavitation can occur during the compression or rebound strokes whether one leg is rebound or one compression it's all about pressure management within the cartridge, the only way to eliminate it completely is to pressurise the cartridge.

[cowpoos]

Wasn't that what Marzocchi did with the M1R forks?
its been done a bit actually...WP,sqoi have sets like this.

[Shaun]

Cavitation is only one aspect that has to be taken account of in the whole system, the few that I've seen that have cavitated have been poorly thought out aftermarket systems, by building a system that builds cartridge pressure rapidly it can be avoided.

Cavitation can occur during the compression or rebound strokes whether one leg is rebound or one compression it's all about pressure management within the cartridge, the only way to eliminate it completely is to pressurise the cartridge.

So Gas forks with one rb and one comp, would be the best way to go? If one leg is trying to do 2 jobs, the chance of cavitation must be higher, than a fork only doing one thing at a time?

[JD Racing]

So Gas forks with one rb and one comp, would be the best way to go? If one leg is trying to do 2 jobs, the chance of cavitation must be higher, than a fork only doing one thing at a time?

Not necessarily, this is where you have to look at the system as a whole and not get hooked up on one thing. If you have one leg doing only one operation then you have to increase the damping force as only one leg is doing the work, this leads to a larger pressure differential which has the potential for more cavitation, so you may need to increase the gas pressure which then adds to the extension force acting on the damper rod, the stiction on the seals...

[warewolf]

ummm...yeah on the cavitation issuse...why hasn't someone though of having a separate air canister away from the forks...Infinity Subtanks (http://www.infinitymachineanddesign.com/)

[Robert Taylor]

Not necessarily, this is where you have to look at the system as a whole and not get hooked up on one thing. If you have one leg doing only one operation then you have to increase the damping force as only one leg is doing the work, this leads to a larger pressure differential which has the potential for more cavitation, so you may need to increase the gas pressure which then adds to the extension force acting on the damper rod, the stiction on the seals...

All fair points. Ohlins get around that issue with their twin tube TTX gas cartridges used in AMA and World Supersport. Gas pressure is 5 bar, quite low. Gas pressure used is always of course indicative of how well pressure balanced the system is. They are a nice piece of kit and appear to work really well. I have no doubts also that WP have something pretty clever.
If they can eventually get these into volume production they should still be affordable as they only have half the number of pistons etc.

[cowpoos]

Infinity Subtanks (http://www.infinitymachineanddesign.com/)
shit a brick...thats what I was thinking. turns out I'm a bit slow on the thinking though!!

anyone else care to make a educated comment?

[Shaun]

Not necessarily, this is where you have to look at the system as a whole and not get hooked up on one thing. If you have one leg doing only one operation then you have to increase the damping force as only one leg is doing the work, this leads to a larger pressure differential which has the potential for more cavitation, so you may need to increase the gas pressure which then adds to the extension force acting on the damper rod, the stiction on the seals...



Would not building a compilation of a lot more shims ( Smaller than the std big piston shims) take care of this?

so there are more shims doing the job as you say, but as there are more, and easier to pass by being small initially, help to control/elliminate the cavitation, as well as the fact the leg is only doing one thing, so this will also aid eliminating cavitation?

Stiction is not really an issue on NZ roads and tracks \i feel, as our conditions are so bumpy any way, that it would take a data loger for a lot of riders here to really notice that NEGATIVE


I am realy just filling in time at the airport weighting for my flight to the Isle of Man TT races, but thanks for the feed back

PS, gis a job MR as a tester for you

[JD Racing]

shit a brick...thats what I was thinking. turns out I'm a bit slow on the thinking though!!

anyone else care to make a educated comment?

they were invented by Ross Maede at Enzo, here is a copy of an email he sent to someone explaining their operation.

"The concept of my subtank system is to create a "speed sensitive spring characteristic". As you know, the two elements of suspension are SPRING and DAMPING. The SPRING element is load or position sensitive. If 10 lbs. is applied to a 10 lbs. per inch rated spring, it will compress one inch. 20 lbs. = 2 inches, etc. But it is not speed sensitive, because if 10 lbs. is dropped on the spring, it will compress more than 1 inch, but after bouncing up and down for a while, it will settle at 1 inch of compression. Adding speed to the situation changes the reaction. The second element is DAMPING, which is speed sensitive. It is like stroking your hand through water: the faster you stroke your hand, the more resistance the water provides. Speed determines the amount of resistant force. But DAMPING is not position sensitive or load sensitive. If a load is placed in the water, it will sink to the bottom. Nothing will hold it in place, only the speed sensitivity will control how fast it sinks.

So the two elements work together to give total suspension action. But my system creates an additional speed sensitive element within the spring characteristic. In a front fork, the TOTAL spring character is determined by the coil spring rate, and the AIR SPRING RATE combined. The AIR SPRING RATE is the compression of the air volume within the fork determined by the oil level. A low oil level provides a large air volume which compresses at a slower progressive rate. A high oil level provides a small air volume which compresses at a faster progressive rate.

The sub tank system provides additional air volume to manipulate. By dividing the total air volume into two "chambers", and separating them with a "restrictive barrier", it is possible to control the compression of the air volume by metering restriction between the two "chambers". The compressing "charge" is created by the inner fork tube entering the outer fork tube. This charge compresses the oil level chamber in the fork. With the sub tank system installed, a high oil level can be set within the fork. The sub tank provides additional air volume, which when combined with the oil level volume is actually providing a large total air chamber volume. When the fork is compressed slowly or uses shorter amounts of stroke, the total air volume of both chambers is compressed equally, giving the sensation of a very low oil level, and the action is soft. But as the fork compression speed increases, or longer amounts of stroke are used, the restrictive barrier prevents equal compression between the two chambers, so the oil level air chamber compresses at a higher rate than the sub tank chamber volume. This gives the sensation of a high oil level in the fork, and the action is firmer. In other words, when the fork is compressed slowly or uses short stroke, it feels like it h as a low oil level. But when the fork is compressed faster, or uses longer stroke, it feels like it has a high oil level. The tuning elements of the system are the volumes of each chamber (oil level and sub tank volume) and restrictive barrier (flow adjustment on sub tank). My system is installed on the stock cap through the air bleed hole, which is drilled out larger and tapped to accept a larger flow fitting. The hoses attach to the cap fittings, and then to the sub tanks. The adjustment flow is the point of greatest restriction.

I hope that this clears up any confusion about the system. The difference between the KAYABA bladder system and my sub tank system is that the restrictive barrier between the two chambers is HYDRAULIC in the bladder system, and PNUEMATIC in the sub tank system. WHich is better? I believe that PNUEMATIC, air restriction is better because air can compress and will not spike. HYDRAULIC, oil restriction is not compressible, so sometimes it spikes. Also, the bladder system is not adjustable, and the sub tank system is. "

[Shaun]

you read to much JD, back to work now snap snap[

[Robert Taylor]

Would not building a compilation of a lot more shims ( Smaller than the std big piston shims) take care of this?

so there are more shims doing the job as you say, but as there are more, and easier to pass by being small initially, help to control/elliminate the cavitation, as well as the fact the leg is only doing one thing, so this will also aid eliminating cavitation?

Stiction is not really an issue on NZ roads and tracks \i feel, as our conditions are so bumpy any way, that it would take a data loger for a lot of riders here to really notice that NEGATIVE


I am realy just filling in time at the airport weighting for my flight to the Isle of Man TT races, but thanks for the feed back

PS, gis a job MR as a tester for you

Thin''scrubbing'' shims. In regular ''single tube'' systems the more agressive the stack ( especially on midvalve ) the greater the chance of cavitation. I need to describe and show you this one on one. JD may want to elaborate in writing.
I disagree with you about stiction.
Night.

[cowpoos]

they were invented by Ross Maede at Enzo, here is a copy of an email he sent to someone explaining their operation.

"The concept of my subtank system is to create a "speed sensitive spring characteristic". As you know, the two elements of suspension are SPRING and DAMPING. The SPRING element is load or position sensitive. If 10 lbs. is applied to a 10 lbs. per inch rated spring, it will compress one inch. 20 lbs. = 2 inches, etc. But it is not speed sensitive, because if 10 lbs. is dropped on the spring, it will compress more than 1 inch, but after bouncing up and down for a while, it will settle at 1 inch of compression. Adding speed to the situation changes the reaction. The second element is DAMPING, which is speed sensitive. It is like stroking your hand through water: the faster you stroke your hand, the more resistance the water provides. Speed determines the amount of resistant force. But DAMPING is not position sensitive or load sensitive. If a load is placed in the water, it will sink to the bottom. Nothing will hold it in place, only the speed sensitivity will control how fast it sinks.

So the two elements work together to give total suspension action. But my system creates an additional speed sensitive element within the spring characteristic. In a front fork, the TOTAL spring character is determined by the coil spring rate, and the AIR SPRING RATE combined. The AIR SPRING RATE is the compression of the air volume within the fork determined by the oil level. A low oil level provides a large air volume which compresses at a slower progressive rate. A high oil level provides a small air volume which compresses at a faster progressive rate.

The sub tank system provides additional air volume to manipulate. By dividing the total air volume into two "chambers", and separating them with a "restrictive barrier", it is possible to control the compression of the air volume by metering restriction between the two "chambers". The compressing "charge" is created by the inner fork tube entering the outer fork tube. This charge compresses the oil level chamber in the fork. With the sub tank system installed, a high oil level can be set within the fork. The sub tank provides additional air volume, which when combined with the oil level volume is actually providing a large total air chamber volume. When the fork is compressed slowly or uses shorter amounts of stroke, the total air volume of both chambers is compressed equally, giving the sensation of a very low oil level, and the action is soft. But as the fork compression speed increases, or longer amounts of stroke are used, the restrictive barrier prevents equal compression between the two chambers, so the oil level air chamber compresses at a higher rate than the sub tank chamber volume. This gives the sensation of a high oil level in the fork, and the action is firmer. In other words, when the fork is compressed slowly or uses short stroke, it feels like it h as a low oil level. But when the fork is compressed faster, or uses longer stroke, it feels like it has a high oil level. The tuning elements of the system are the volumes of each chamber (oil level and sub tank volume) and restrictive barrier (flow adjustment on sub tank). My system is installed on the stock cap through the air bleed hole, which is drilled out larger and tapped to accept a larger flow fitting. The hoses attach to the cap fittings, and then to the sub tanks. The adjustment flow is the point of greatest restriction.

I hope that this clears up any confusion about the system. The difference between the KAYABA bladder system and my sub tank system is that the restrictive barrier between the two chambers is HYDRAULIC in the bladder system, and PNUEMATIC in the sub tank system. WHich is better? I believe that PNUEMATIC, air restriction is better because air can compress and will not spike. HYDRAULIC, oil restriction is not compressible, so sometimes it spikes. Also, the bladder system is not adjustable, and the sub tank system is. "
Thanks for that...I'm guessing that because thee is a production example already...and its not really seen in racing circles that it has limitations or its not that greater concept in the scheme of things???

[JD Racing]

The more pressure you have within the system, the more pressure you have acting on the seal, the more pressure you have on the seal the more force it applies to the shaft so the more stiction you have.

[Shaun]

Cheers JD and Rob. Hey Doc, i will be back to school after the 21st of June.

[Robert Taylor]

Thanks for that...I'm guessing that because thee is a production example already...and its not really seen in racing circles that it has limitations or its not that greater concept in the scheme of things???

Its more useful and used in MX because of terrain variation and the tracks change / cut up during a long moto. They also have 300mm of fork travel, we have 120 odd mm.
MX suspension dynamics are by implication more extreme. We see ''kerb strike'' velocities in road race of up to around 800mm / second ( turn 1 at Pukekohe ) Puddle jumpers 4 to 5 metres per second.
Also the more effective the damping response is the more you ''catch the horse before it bolts from the stable door'', so to speak. Forks that have less effective damping over-rely on high fork oil level to arrest the relatively uncontrolled movement.
MX forks tend to have much softer midvalve calibration so arguably they rely moreso on oil level / trapped air compression ratio for final control. Damn puddle jumpers!

[Robert Taylor]

The more pressure you have within the system, the more pressure you have acting on the seal, the more pressure you have on the seal the more force it applies to the shaft so the more stiction you have.

Have you seen those dodgy red coloured 3 lip fork seals peddled around the world and here in NZ? Theyve got the temerity to say they are very low friction. The results are;

1) Very high friction

2) If fitted to forks with titanium nitrate or DLC coatings it wears it off a lot faster

When I see these pieces of cr.p I just shake my head that people are so gullible.

[JD Racing]

I've not seen the red ones but I have worked on a couple of sets of forks where the owners have proudly boasted of having fitted "no leak seals", those things don't leak because they grip the shaft in a vice like fashion, unbelievable amounts of stiction, it's like having to overcome an extra 20mm of preload.

The coatings wearing off is down to the shocking quality of Japanese coatings, not only is it poor, it's inconsistent, no two fork legs are the same, it shouldn't wear at all that's the whole idea of it, you should be able to attack it with abrasive paper and it just laugh in your face, try that with an oem tube and it will surrender faster than a northern hemisphere front row.

[Robert Taylor]

I've not seen the red ones but I have worked on a couple of sets of forks where the owners have proudly boasted of having fitted "no leak seals", those things don't leak because they grip the shaft in a vice like fashion, unbelievable amounts of stiction, it's like having to overcome an extra 20mm of preload.

The coatings wearing off is down to the shocking quality of Japanese coatings, not only is it poor, it's inconsistent, no two fork legs are the same, it shouldn't wear at all that's the whole idea of it, you should be able to attack it with abrasive paper and it just laugh in your face, try that with an oem tube and it will surrender faster than a northern hemisphere front row.

Exactly and I agree with you about the microscopically thin DLC coatings etc, a marketing exercise more than anything, ''race replicas'' etc. Yeah right. The proper race ones have something like a 15 step process. Coat, polish, recoat, repolish etc.
But fitting low quality and especially these ''no leak'' / ''vice grip'' seals just invites disaster a whole lot sooner.

[Mishy]

Thin''scrubbing'' shims. In regular ''single tube'' systems the more agressive the stack ( especially on midvalve ) the greater the chance of cavitation. I need to describe and show you this one on one. JD may want to elaborate in writing.
I disagree with you about stiction.
Night.

So i'm assuing that the strong mid valve can be what causes the pressure imbalance that causes cavitation ? if i remember rightly the mid valve would need to be weaker than the base valve to allow a re-balance of pressure as the fork compresses, and a strong midvalve would lead to over use of the base valve, with a corresponding drop in pressure above the midvalve ?

[JD Racing]

So i'm assuing that the strong mid valve can be what causes the pressure imbalance that causes cavitation ? if i remember rightly the mid valve would need to be weaker than the base valve to allow a re-balance of pressure as the fork compresses, and a strong midvalve would lead to over use of the base valve, with a corresponding drop in pressure above the midvalve ?

The midvalve needs to be weaker than the base and weak enough at low cartridge pressure to prevent cavitation, it's generally used to supplement the base, it's not that big a deal, it's not the only method to add damping.

[Robert Taylor]

So i'm assuing that the strong mid valve can be what causes the pressure imbalance that causes cavitation ? if i remember rightly the mid valve would need to be weaker than the base valve to allow a re-balance of pressure as the fork compresses, and a strong midvalve would lead to over use of the base valve, with a corresponding drop in pressure above the midvalve ?

Also the base valve works on shaft displacement, primarily.

[Shaun Harris]

Also the base valve works on shaft displacement, primarily.


so, that's kind of like the size of a pennis then?

[Robert Taylor]

so, that's kind of like the size of a pennis then?

Shaun size! ( small Im led to believe )

[Shaun]

Shaun size! ( small Im led to believe )




displacement mate, ie parting of the ways, exscuse me ladies