a question about spring rate vs valving!

bclapham

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Nov 5, 2001
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If a bloke (1) weighs X pounds, it follows that he will need certain spring rates (Y) to get the correct race and free sag etc.

Now, if his mate, bloke (2) weighs the same X pounds but is a much faster rider (on the same track), will he use the same rate of springs?

I would think yes, since otherwise his sag settings would be off, but he would use stiffer valving to cope with the harder landings. Is this correct?

thanks :p
 

marcusgunby

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Jan 9, 2000
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Yes pretty much-however each rider has his own preference-my friend who is over 50 and rides a Cr125 doesnt like the soft setup i gave his bike-i was alot softer than stds but almost as stiff as mine-he went back to std springs(bear in mind he weighs 130lb)and much prefered it-he is so used to std hard setups , he cannot ride on a plush setting.

Also often a faster rider will ride better and not hit the face of jumps etc so could actually get away with a soft setup-Stefan Everts is said to like a really plush bike as did Jeff emig.I think the riders who need a stiff setup are midspeed expert riders, they know how to go fast but havnt the top skills to do it smoothly.I often case a jump slightly where as a championship rider will land the downside and the suspension is hardly used.
 

bclapham

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Nov 5, 2001
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So, is it correct that the rate of rebound damping is also related to the spring rate? Thus, if the faster rider wanted stiffer damping, the main ciruit that would modified would be the compression (rather than the rebound) since the rate of rebound would be related to the spring rates which are the same for those 2 riders?

Conversly, does it follow that their other mate (bloke 3) that weighs 50 pounds heavier would need a stronger spring rate and also, stiffer (slower) rebound damping to control that stronger spring?

and back to my predicament, since all my sag settings are correct, can we assume that my spring rates are good to go? can i save money by just sending my shock for a simple revalve without paying the extra for new springs?
 

marcusgunby

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Jan 9, 2000
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Bruce correct on every count-your sag number indicate no new spring is needed.See your not as dumb as you make out;)
 

bclapham

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Nov 5, 2001
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OK, last few questions.....honest!

i read lots on hear about shim stacks, however, i also notice that there are several stacks in both the fork and the shock.

1. is this correct

2. are the shim stacks for compression and rebound independant?

3. Assuming the valving is matched correctly for the spring rate, then if my suspension is too stiff then all that would be required is to remove some of the stiffness from only the compression circuits?
 

bclapham

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Nov 5, 2001
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oh, one more quick question!

i seem to have convinced myself that my shock damping (both ways is too stiff), i have backed both the compressions right out, but i am only 10 clicks out on the rebound, since i seem to have the kicking up feeling when i leave the top of a jump.

could it be that the suspension feels stiff since the rear is packing and the wheel is not rebounding quickly enough and have i possibly diagnosed the need for too much rebound incorrectly,since i am not riding over the jumps in the proper fashion?
 

marcusgunby

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Jan 9, 2000
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Bruce you dont need me im only confirming stuff these days:)
The forks have 3 stacks we can adjust ,the base valve, which is called the passive as it sits doing nothing and oil is forced through it(commonly modified) the midvalve(active, because it is rammed through the oil)less modded as its harder to get at.And rebound-rarely adjusted unless big changes in spring rates.

All stacks are indepandant but some have a effect on others.
The rebound has a odd effect of changing the overall feel of a fork-sometimes altering the rebound can make more differerence to fork feel than the compression.

3 Yes but remember there is no such thing as right or wrong-its only wrong if you dont like it-another rider may love the feel of your suspension-he maybe the same weight and speed.

Its all about tailoring the bike to the rider-its a very hard thing to get right, as alot of riders think they want one thing, and yet rarely like it.
Its taken me over a decade of riding to realise i like a smooth engine not a hard hitting monster-loads of fun but slow on a track.
 

marcusgunby

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Jan 9, 2000
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Yep i think you have too much rebound-alot of riders who lack confidance like alot of rebound so they dont have to deal with the rear end when jumping-this means it will pack and feel dead and harsh-alot of top expert rider have very little rebound so the bike stays higher in the stroke and will react to the next bump-some feel almost unrideable but when the throttle is on they work well-dont shut off up the face of the jump what ever you do when riding one of these super quick rebounding shocks.Also a fast rebound allows the rear to come up over jumps to get the front wheel to land 1st without using the back brake-suspension is alot plusher when landing front wheel 1st-both wheel landings really hurt on any suspension.
 
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