Top-out springs?

[Yankee Doodle Dandy]

Its just that our workload is mental

Sounds like you need more employees - I just so happen to know an American looking for a job......

[JD Racing]

http://www.onthethrottle.com/content/view/375/40/


Robert will like these guys thoughts on top out springs.

[Yankee Doodle Dandy]

It seems some tuners advocate removing them from the shocks and some don't.

As Mr Taylor said, Penske does not use them. I do not know what Showa does on their kit and works stuff.

I know that years ago one factory AMA team had tested shocks with and without top out springs and that at least one rider preferred the top out spring removed.

[Pussy]

one rider preferred

There is the relevant point.
Not every rider likes the same thing.
As a suspension tuner, you can't say "when I want your opinion, I'll give it to you"
You've got to find out what the rider WANTS

[Robert Taylor]

http://www.onthethrottle.com/content/view/375/40/


Robert will like these guys thoughts on top out springs.

Yes I have just watched it, why do these guys effectively ''assume'' or even mislead that there is only one rate of topout spring? They are not hard to change and do quickly if you have a vacuum bleeder to hand. In some ways I suspect that many trackside tuners dont like this added variable.............??

Soft springs have to be balanced with soft top out springs.

At Philip Island WSBK pre season tests nearly two years ago I spent a whole day testing varying rates and lengths of top out springs with Katsu Fujiwara. We also tested with no top out springs but an important point here is that with no top out springs you also have to run a steeper nose part of the low speed rebound damping curve, the curve has to be reshaped with a new valving and bleed clicker setting. Thats another subject!

Conclusions from that test were that when everything was balanced properly you had better rear wheel stability under braking and more sidegrip with top out springs, it did show on the telemetry.

Note that the oem 07 ZX6RR has a dreaded topout spring!!

Shortly we are going to test a new Race Tech shock, they in line with US thinking do not have a top out spring. Im open minded, this will be interesting.

[Yankee Doodle Dandy]

You've got to find out what the rider WANTS

The problem is that a lot of riders have no clue what they want.

What is the worst thing a rider can say to his mechanic/tuner?

[Shaun]

The problem is that a lot of riders have no clue what they want.

What is the worst thing a rider can say to his mechanic/tuner?

Fix it, NOW

[DrZeeple]

Sorry to butt in; but my involvement is not high enough to send PM's, or I would have! So, this is the only way to show a little info-update stuff...

T/O's are like RT said a massive subject, heaps of fun when you have them all in your toy-box and have played with them in conjunction with shock designs and linkages; damper curve shapes (etc etc), the practicable possibilities, they go on and on!

Anyhow, back on topic: we have had these Penske neg. springs since the end of last year - they're OK; but their approach I suppose you might say is closer to how Factory Showa play things, and thus a similar approach is required....

As regards that D Moss character, nah I ain't feeling it there at all (tuning is all internal, the rest is knob-juggling!) - nearly each one of those videos promotes something just plain wrong (sag setting? please!); to make a video for helping everyone comprehend more than they do is one thing; but should said video misrepresent the subject matter, or in some way or other be ambiguous, then it causes harm n'est pas?!

One such EG that comes to mind is when he has an FGK kit in a 675 and thus proclaims that if it is 2 clicks out or 9 clicks out @ the rebound then it must be one type of valving or the other (presumably between 1670-01/2061 or -04/-03 pistons and related spec changes). However one should never promote rebound to be run that low if possible, to allude as such is potentially harmful! (grrr!)

Anyways, I'm off - gotta say it is lovely to see you all so interested in things; but I have no intention of living in NZ again for the foreseeable future (tho' never say never eh!); so shan't bother you all; just thought you may have interest in the 2009 Penske optional update...

[Robert Taylor]

Sorry to butt in; but my involvement is not high enough to send PM's, or I would have! So, this is the only way to show a little info-update stuff...

T/O's are like RT said a massive subject, heaps of fun when you have them all in your toy-box and have played with them in conjunction with shock designs and linkages; damper curve shapes (etc etc), the practicable possibilities, they go on and on!

Anyhow, back on topic: we have had these Penske neg. springs since the end of last year - they're OK; but their approach I suppose you might say is closer to how Factory Showa play things, and thus a similar approach is required....

As regards that D Moss character, nah I ain't feeling it there at all (tuning is all internal, the rest is knob-juggling!) - nearly each one of those videos promotes something just plain wrong (sag setting? please!); to make a video for helping everyone comprehend more than they do is one thing; but should said video misrepresent the subject matter, or in some way or other be ambiguous, then it causes harm n'est pas?!

One such EG that comes to mind is when he has an FGK kit in a 675 and thus proclaims that if it is 2 clicks out or 9 clicks out @ the rebound then it must be one type of valving or the other (presumably between 1670-01/2061 or -04/-03 pistons and related spec changes). However one should never promote rebound to be run that low if possible, to allude as such is potentially harmful! (grrr!)

Anyways, I'm off - gotta say it is lovely to see you all so interested in things; but I have no intention of living in NZ again for the foreseeable future (tho' never say never eh!); so shan't bother you all; just thought you may have interest in the 2009 Penske optional update...

Thanks for the input and Im glad that Im not the only one that is wary of Dave Moss's ''blanket'' statements. Its posted on the internet so it must be correct? (Yeah right ) I rather think that the engineers at the Ohlins factory know rather more about top out springs than he does! ( I was up in Sweden a month or so ago and was discussing top out springs with the racing manager )
Concedingly yes youve got to have a big box of toys, dedication and willing articulate riders to get the best out of it. In NZ the riders that spring to mind that fall into that category are Andrew Stroud, Craig Shirriffs and Shaun Harris.

Interesting that Penske now offer such an option, there are a few other things they do rather well.

[JD Racing]

Yes I have just watched it, why do these guys effectively ''assume'' or even mislead that there is only one rate of topout spring? They are not hard to change and do quickly if you have a vacuum bleeder to hand. In some ways I suspect that many trackside tuners dont like this added variable.............??

Soft springs have to be balanced with soft top out springs.

At Philip Island WSBK pre season tests nearly two years ago I spent a whole day testing varying rates and lengths of top out springs with Katsu Fujiwara. We also tested with no top out springs but an important point here is that with no top out springs you also have to run a steeper nose part of the low speed rebound damping curve, the curve has to be reshaped with a new valving and bleed clicker setting. Thats another subject!

Conclusions from that test were that when everything was balanced properly you had better rear wheel stability under braking and more sidegrip with top out springs, it did show on the telemetry.

Note that the oem 07 ZX6RR has a dreaded topout spring!!

Shortly we are going to test a new Race Tech shock, they in line with US thinking do not have a top out spring. Im open minded, this will be interesting.

The top out springs would have no impact on side grip unless you were running exceptionally long ones, the G loading mid turn would take you well out of the range of the top out, the changes in side grip would be explained by the changes in the low speed and bleed that you'd made.

Top out springs add a geometry element to the suspensions function, for example long top out springs in the forks can stop wheelies but so can steeper swing arm angles they can also make the forks work low in the stroke making the steering nervous, nervous steering can also be caused by a steeper swing arm angle. You need to look at all aspects of the bike, head angle, offset, trail, crank height, swing arm angle, wheelbase etc, etc.

[Robert Taylor]

The top out springs would have no impact on side grip unless you were running exceptionally long ones, the G loading mid turn would take you well out of the range of the top out, the changes in side grip would be explained by the changes in the low speed and bleed that you'd made.

Top out springs add a geometry element to the suspensions function, for example long top out springs in the forks can stop wheelies but so can steeper swing arm angles they can also make the forks work low in the stroke making the steering nervous, nervous steering can also be caused by a steeper swing arm angle. You need to look at all aspects of the bike, head angle, offset, trail, crank height, swing arm angle, wheelbase etc, etc.

It depends on what part of the corner we are talking about of course. If its about corner entry leading up to transition then yes the top out spring does have an effect on sidegrip. And isnt suspension also about controlling / regulating change of geometry.

[JD Racing]

I think we have a difference in the definition of sidegrip there, sidegrip to me is during and after the transition, not before. If you have a rider who's backing it in all the way to the apex, side grip is not an issue, it's only when the front brake is released and weight trnsfers to the rear that side grip is important.

Some parts of a suspension unit control geometry to an extent, top out springs to me have more of a geometry function than a suspension function.

[Yankee Doodle Dandy]

What is the worst thing a rider can say to his mechanic/tuner?

Fix it, NOW

Nope.

Its "I was thinking........."

[Shaun]

Nope.

Its "I was thinking........."

Ha ha, and in 3 hours from that comment, YOU have a totaly different bike! Whether it works or not is another ? though

[Yankee Doodle Dandy]

Soft springs have to be balanced with soft top out springs.

I figured that the stiffer the main spring, the stiffer the top out spring.

I checked a couple of the Ohlins spec cards to get an idea of how much they increase the top out springs rate in conjunction with a higher rate main spring and I found interestingly enough, Ohlins matches up a 4 N/mm top springs with 9.0 N/mm main springs in their FGK 132 (GSX-R600/750) kit but then installs a 3.5 N/mm top out springs with 9.5 N/mm main springs in their FGK 138 (Ducati 848/1098) kit.