Damping Technology

[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

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

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.