Question for JD Racing and Robert T

[Robert Taylor]

Guys, what is your opinion on this

OK, we have a bike sitting in front of us, lets say it is all set up ( ie, the suspension settings) for a fast track racer, say Craig Shirrif or Dom Jones

these guys can do a 1.47.6 lap time on it, which is quicker than lap record of last year

Now give that same bike to a rider to use on the road, all suspension settings still as per the track,

To the average road rider-

1) Would the bike probally feel fantastic?

2) Or would the bike probally feel very harsh on bumps etc


I know the question is a bit limited ( But so am I ) but am also very sure you both will understand the question fully

Its a no brainer and frankly also the level of local road racing has moved on substanially, its getting harder and harder for someone to win races with stock or average aftermarket bits, unless they want to stick their kneck out right on the edge or exceeding their comfort zone. And frankly also a lot of oem and cheap aftermarket stuff looks very ugly at elevated speeds.

The question is indeed oversimplistic because there is no allowance for rider height and weight and myriad other factors. SIMPLY, the suspension must be set for the application, skill level, rider height weight and style, perception of feel he/she wants, overall loading ( passengers, baggage etc ) and there must be a response range to make spring preload and clicker changes. This very often involves internally resetting the suspension. I can remember one road racer of average weight who wanted everything rock hard, it worked for him but would be unrideable for everyone else.

Robbie Bugden uses the exact valving spec we developed with Craig Shirriffs but because he is shorter and lighter uses a spring rate typically 2 steps lighter. Damian Cudlin uses a valving spec 1 step firmer than Gareth Jones because he likes a steeper damping curve build up at mid to higher shaft velocities to ''catch'' the looser low speed damping feel he prefers, and so on...The more riders you work with the more you can join all the feedback together to get an overall picture of what is going on. We get feedback from rank amateurs that has also proven to be valuable, in spite of different ways of describing things.

Given the same rider stats and machine a top level road racer will require a lot different internal valving spec, springing and geometry simply because at higher velocities and corner speeds everything is loaded to a much higher degree. And what about the loadings that high grip level tyres place on the chassis? Adjustments to INTERNAL by pass bleed for track and tyre temperature etc. ( able to do so externally on very low dispacement shocks such as TTX36 )

The great misconception incorrectly perpetuated by some and believed by some is that external clickers are a magic cure all for all track and road conditions. That may appeal to those who want things to be as simple as possible but the reality is not as rosy, given that the manufacturers / onsellers who perpetuaute this myth have their own ''setting banks'' of internal valving specs for varying rider weights and also skill levels. It is up to the seller of suspension product to have an intimate internal knowledge of shim stacks, by pass bleed and myriad other factors that affect function such as hysterisis when a shock shaft changes direction etc. This game is a whole lot more complex than many choose to beleive.

I have been down the track where some overseas suppliers have brazenly stated that the settings are perfect and youll never have to revalve, ever! Just wind the clickers..... Yeah right..... An American rider turned up with one of these ''fabled'' shocks a couple of years or so back and it got promptly ditched for an Ohlins so the bike could ride the bumps at Pukekohe.

Proudly we always send out stuff set up specifically for the customer and if further optimistaion is required we do so, for road or track, two distinctly different applications.

[cowpoos]

what if a shock with high and low speed compression damping is used?

Depends alot on how and if the shock has be specifiacally set up for you.
and High speed compression is not understood very well...and it has a limited amount of effect in alot of different circumstances..more value should be placed on correct internal valving spec for rider and motorcycle in theit normal operating conditions..and low speed compression adjustmen for rider prefference [low speed adjustment does have an effect across the range aswell as just low speed too]

and if your taking about a stock shock [high and low speed version] its a gimmick!

[Robert Taylor]

Depends alot on how and if the shock has be specifiacally set up for you.
and High speed compression is not understood very well...and it has a limited amount of effect in alot of different circumstances..more value should be placed on correct internal valving spec for rider and motorcycle in theit normal operating conditions..and low speed compression adjustmen for rider prefference [low speed adjustment does have an effect across the range aswell as just low speed too]

and if your taking about a stock shock [high and low speed version] its a gimmick!

If you were only allowed to have 1 damping adjuster on the shock the first choice would have to be rebound. If 2 were allowed add low speed compression, and I mean a true low speed compression adjuster that adjusts damping from the moment it moves from zero velocity. Note that normal displacement dampers do not adjust low speed damping, it is more like mid speed damping. If allowed 3 adjusters third choice would be high speed rebound. If allowed 4 then high speed compression, BUT a true high speed compression adjuster that is acting as a poppet in the main piston shaft, not acting on the displacement of the shaft like Ohlins 46PRX, WP, Penske etc.

We work with NZs fastest tin top race car, a TVR Tuscan fitted with 4 way adjustable Ohlins TTX40 dampers. With these dampers there is a valving reference programme that you can input your new proposed settings into and overlay on your current, very cool and over a million combinations. With high and low speed its also about overlap and shaping the curves.

Allied with this the team also has top of the line Motec data logging system inclusive of track mapping, g sensors, tyre temperature pyros and percentage of time in low speed / high speed rebound and compression. Its taken a while to understand all of this and interface it with our seat of the pants experience. But, the logging really has identified cause and effect.

This is not being arrogant or cynical, it is fact....most riders have trouble working with one damping adjuster. I could pick on a sample of 10 bikes at a track day and 5 or more would have too much rebound damping. ( For example )

Poos is correct, with oem shocks high and low speed it is largely a gimmick there for marketing reasons, a little akin to stick on carbon fibre, ''adding '' lightness!

In road racing Robbie Bugden, Dennis Charlett and Glen Williams are not asking for shocks with dual hi and lo speed.

I would be happy to provide the enquirer with graphs of high speed adjusters on two different brands of shock.

[Robert Taylor]

Isn't the point of having high and low speed compression damping to reduce the compromise between smooth and bumpy set ups?
I may well be talking shit

Think about this, on a fast flowing track ( just Like JD referred to ) you can often have a soft set up because there are no major chassis disturbances. On a bumpy track you can often end up with a firm setup! Bear in mind that here in this 3rd world communist country we must run standard links. Within limits more low speed compression is run to keep the suspension high in the stroke in the supple part of spring and link travel. Very often this may be allied with a steep higher shaft speed damping curve to ''arrest'' sudden shaft movements. There are several different ways to skin the cat.

On conventional displacement dampers it is arguable that high speed damping adjusters have been fitted as an adjustable dump valve because the shocks are reactive and dont damp in real time. Oversimplistically there has to be a lot of low and mid speed ( not mid stroke!!! ) damping to ''catch the runaway train'' And because there is so much damping there has to be a means of dumping it at higher velocities. JDs input would be interesting on this one.

It seems that with the TTX36 it damps a hell of a lot closer to real time so it is catching the movement a lot sooner before it has built up momentum. So less damping is required which means there is much less or in fact no requirement for a high speed adjuster to bleed off too much damping aggression at higher velocities.

Ho hum....

[R6_kid:Me]

Even though i know sfa about the internals of a shock this is proving very interesting...

[cowpoos]

If you were only allowed to have 1 damping adjuster on the shock the first choice would have to be rebound.

That would be why [and as its be explained to me]..[why another person [whos not on KB and not in NZ] I have been learning about damping off reffers to rebound as traction??? and the area I explored more on my bike over the VMCC winter series than any other [and on my RMZ250. all though it has a not very dramatic effect from what I can tell on the stock shock.] starting with when yourself and TDC released some extra rebound on my bike on the second round after I was having hook up issuses at manfield [and killing a other wise good slick]

one thing that I still query about the TTX shock is having to reley on a ohlins techincian being on hand for Valving changes at the track to tune the TTX...and by no means am I putting the product down as I'm yet to try it...and have heard nothing but hugly positive sentiments towards it...and also you are at almost every race meeting club level or national level supporting your product..

and...when are the TTX fork cartridges avalible??

[slowpoke]

Ok, so all the quick fuckers out there have a certain way they like the bike to "feel"....have you guys ever experienced a situation where a top level racer didn't like the way their bike was handling but found it was quicker than than their "normal" set-up?
The reason I ask is that those of us with very little experience and/or access to expert assistance often make a change to our bikes and have difficulty quantifying the results. Often the bike "feels" worse but without a stopwatch and the ability to ride several virtually identical hardcore laps in a row then it's hard to actually verify.
I mean all the Ducati Desmosedici reports I've read (I fuggin' lurve that thing!)indicate it feels ugly at mere mortal speed but as soon as the rider starts amping up the pace it is transformed into the ultimate track tool (as opposed to myself who also happens to be a track "tool" but in a more colloquial way). What do you look for to make the call between "this feels like shit, I'm gonna crash if I go faster" as opposed to "gawd, this feels like shit, so I better go faster"?

[Robert Taylor]

That would be why [and as its be explained to me]..[why another person [whos not on KB and not in NZ] I have been learning about damping off reffers to rebound as traction??? and the area I explored more on my bike over the VMCC winter series than any other [and on my RMZ250. all though it has a not very dramatic effect from what I can tell on the stock shock.] starting with when yourself and TDC released some extra rebound on my bike on the second round after I was having hook up issuses at manfield [and killing a other wise good slick]

one thing that I still query about the TTX shock is having to reley on a ohlins techincian being on hand for Valving changes at the track to tune the TTX...and by no means am I putting the product down as I'm yet to try it...and have heard nothing but hugly positive sentiments towards it...and also you are at almost every race meeting club level or national level supporting your product..

and...when are the TTX fork cartridges avalible??

Yes indeed rebound is about traction, every length of tarmac has hollows / depressions in it so the wheel must react downwards fast enough for the tyre to find the track. The rebound speed ( both high and low speed ) must be fast enough to allow it to do so. I can push on a whole row of bikes and find a lot with too slow rebound.

With respect to trackside revalving of TTX36 and the fact I am there doing so is your observation /perception and one that competitors ( who offer no at track revalving ) love to perpetuate.''They need work and ours dont''. ( BOLLOCKS ) But thats also because there is a void in equipment, experience or in depth training to do so.

So hear it from the horses mouth guys.......we used to also do so with older style 46 series ( and still do ) BECAUSE I AM INTENSELY INTERESTED AND THIS IS WHAT I DO. Case in point the TTX concept is so new and we are doing ongoing work that gets fed back to the factory.

We could not turn up and because the response range to external adjustment is so wide they would still work very well. We pulled a bone stock one out of its box at last years round of the nationals at Manfield, fitted it to Chris Seatons R1 and he promptly smashed the lap record.

And then ( for example ) we have custom built TTX for SV650s as Ohlins dont make for same. This was a protracted development over the winter with Glen Williams and bless him he is now reaping the ultimate benefit with the F3 national title in his sights. Terry Fitz also piggybacked onto this and the superiority of their suspension was emphatically apparent at Paeroa on the weekend.

I feel happy to provide such service and as a reality check it needs to be re-iterated that a whole lot of it is goodwill at no charge.

Stay posted re TTX cartridges, I worked with 600 Supersport ones at Philip Island and they are very very good.

[Robert Taylor]

Ok, so all the quick fuckers out there have a certain way they like the bike to "feel"....have you guys ever experienced a situation where a top level racer didn't like the way their bike was handling but found it was quicker than than their "normal" set-up?
The reason I ask is that those of us with very little experience and/or access to expert assistance often make a change to our bikes and have difficulty quantifying the results. Often the bike "feels" worse but without a stopwatch and the ability to ride several virtually identical hardcore laps in a row then it's hard to actually verify.
I mean all the Ducati Desmosedici reports I've read (I fuggin' lurve that thing!)indicate it feels ugly at mere mortal speed but as soon as the rider starts amping up the pace it is transformed into the ultimate track tool (as opposed to myself who also happens to be a track "tool" but in a more colloquial way). What do you look for to make the call between "this feels like shit, I'm gonna crash if I go faster" as opposed to "gawd, this feels like shit, so I better go faster"?

Yes, yes and yes. The set up difference between Robbie Bugden and Andrew Stroud is like a polar opposite. The Japanese use a term ''rider feel''. Most often if the rider likes what he feels he will often go faster. A notable exception is my pet hate that we find most often with novice riders, TOO MUCH REBOUND. If you see me at a track, sure I am busy. But if you have questions come and ask, I can very often talk to people while I am working.

[dino3310]

my wrists and lower back are getting sore just thinking about track set up on the road, but i'ld be stoked to be riding a bike set up by the famous you so it would be worth it

[JD Racing]

On conventional displacement dampers it is arguable that high speed damping adjusters have been fitted as an adjustable dump valve because the shocks are reactive and dont damp in real time. Oversimplistically there has to be a lot of low and mid speed ( not mid stroke!!! ) damping to ''catch the runaway train'' And because there is so much damping there has to be a means of dumping it at higher velocities. JDs input would be interesting on this one.

I'm not convinced of the whole runaway train concept, a correctly balanced shock will respond very rapidly, also we are not talking about a precision operating apparatus, if the TTx has an advantage we are talking about milliseconds, between the input at the wheel and the shock, you've got a tyre with variable stiffness, a long lever which flexes, twists and bends and a myriad of needle roller bearings, tie rods and rocker arms all with seals on, then to finish the job off the shock is sheathed with a bent piece of rod.

The PRX and the adjusters on WP, Wilbers etc are effectively dump valves, the shock you love to hate though does have an adjuster that operates in a more mid speed range.

[Robert Taylor]

I'm not convinced of the whole runaway train concept, a correctly balanced shock will respond very rapidly, also we are not talking about a precision operating apparatus, if the TTx has an advantage we are talking about milliseconds, between the input at the wheel and the shock, you've got a tyre with variable stiffness, a long lever which flexes, twists and bends and a myriad of needle roller bearings, tie rods and rocker arms all with seals on, then to finish the job off the shock is sheathed with a bent piece of rod.

The PRX and the adjusters on WP, Wilbers etc are effectively dump valves, the shock you love to hate though does have an adjuster that operates in a more mid speed range.

The proof though has been in the pudding and if it is milliseconds ( which I have always thought ) then that is enough. All of the other factors you mention are a relative constant, but if you have a shock that is more reactive more quickly then it makes sense. If you do better work at the very start of stroke there is then less effort required to control movement later on. ( I know that sounds simple ) Heck, you and I have played around with settings that mess with hysterisis ( delay or otherwise in damping buildup ) and noticed a difference. So minimising the delay is a good thing.

Yes indeed they are dump valves and although some people maligned the Ohlins one I have found the response range to be quite reasonable, and it is a ''slope adjuster''

I didnt say I hate that shock, just the ill informed and frankly incorrect hype that is going on about no revalving required. My own dyno graphs concur that it is a mid speed adjuster that gives a second knee that does nothing to the slope angle, it just parrallells it. Personally, I think it is more ideal to alter the slope angle, especially for bumpy tracks and my own experience working with both systems confirms that.

[johnsv650]

hi robert,
i read above about glen williams and terrys shocks, how much inprovement are they over a shock which is about 3 years old ?
your help at the nationals has been outstanding and many thanks to you and kerry........fantastic service........well its more than service.......
might have to budget for next year new shock and forks.....
john

[Robert Taylor]

hi robert,
i read above about glen williams and terrys shocks, how much inprovement are they over a shock which is about 3 years old ?
your help at the nationals has been outstanding and many thanks to you and kerry........fantastic service........well its more than service.......
might have to budget for next year new shock and forks.....
john

Probably best to talk to Glen, he did all the testing...and its only fitting in that sense that he is going to achieve his goal. PM me at some stage or talk to me at the next round and I will fill you in as I have some good options.

I dont think the service is good enough yet and we aim to improve it. I have been notified today that we will have a Swedish engineer out from Ohlins later in the year so we will be planning some sort of seminars. As these guys are at the very top of the game in the motorcycle suspension world this will be something to look forward to....

[White trash]

It depends on what the racer likes, I do a lot of work with a guy who likes a very particular set up, he was leading a race by 20+ seconds so backed off, he said the bike felt so shit when he was no longer loading the suspension at race pace he had to speed up again because the bike was scaring him.

Other riders who go through all the transitions very smoothly, brake, lay the bike on it's side, pick it up again on the throttle all in one very smooth flowing arc, hardly upsetting the bike, you could ride their bike down to the shops with a tray of eggs on the back and not smash one.

Interestingly, I've seen this very regularly in my own very short racing career. Shaun's a nice enough bloke to have helped me immensly from the beginning of this.

When I first rode his 600 at Puke' in April last year, I took it easy for the first practice session and felt thoroughly uncomfortable. The bike felt "pitchy" and unstable. Second session and I decided to see what I could do on the current setup. As soon as I got aggressive, the bike got good. And I mean REAL good. I felt like I could get away with murder on it

I witnessed exactly the same thing at a following trackday. A suspension tuner had a fiddle with a racers SV650. The racer sent his mate racer for a test ride who promptly proclaimed the bike was crap and they'd just undone six months of hard work. The racer then rode the bike himself, stating the exact same thing. The tuner thinks "This can't be right!" climbs on the bike himself and runs three laps 5 seconds per lap quicker than the racers. All they needed to do was get aggressive with the thing.

I think this is where the difference lies between a well set up track bike and road bike. You simply can't ride a bike on the road with the aggression to make a well set up race bike handle well.

Make sense? Thought not