Racetech goldvavles freek wanted

Joined
Jun 25, 2000
Messages
378
Likes
0
#1
I have had problems with my twinchamber forks on my bike being too harsh. I installed gold valves and set the recomended stack and it was a big difference but still too harsh. I already ran almost the softest setting and it was bottoming so i though i couldnt go softer. But today i went out of the valving chart and made my own stack. I added more oil in hope it wont bottom but yet be soft in the 1/2 on the stroke. Havent tried in on the track yet.

I also changed the low speed "base plate"(i forgot its name) that is the same size and thickness on every stack. From .15mm thick to .10mm. What i have done i dont think is recomended as no setting is like this so i would like to know what i have really changed. What aspects on the suspension do the different parts affect? Can i get a very plush 1/2 of travel and yet not bottoming and being overall good by doing what im trying to?
 

marcusgunby

Lifetime Sponsor
Joined
Jan 9, 2000
Messages
6,450
Likes
2
#2
Dont be afraid to experiment and make big changes-ive heard of people saying the RT stacks are too stiff-your use of 0.1mm shims will make it a good deal softer-which is what you want-get the desired plushness and then add oil to prevent bottoming.
 
Joined
Oct 30, 2002
Messages
277
Likes
0
#3
If it is the clamping shim (the bottom shim on the stack) that you have changed from .15 to .1 it will make the stack harder.
 

marcusgunby

Lifetime Sponsor
Joined
Jan 9, 2000
Messages
6,450
Likes
2
#4
dbrace is correct-i didnt read it well enough-you should always use a thick clamp shim.This allows the stack to flex over clamp but not hit the valve body.
 

JohnScott

Subscriber
Joined
May 22, 2001
Messages
96
Likes
0
#5
Marcus, I've been playing with my shims recently (RT GVs). I use a 18X.5 as the clamp shim. But, above that, I am thinking of trying a 12X.25 instead of the normal 12X.15. What effect will that have? I was thinking it would make the whole stack softer as it gives the entire stack .10mm more room to flex, or open. What do you think?

John
 

bclapham

Lifetime Sponsor
Joined
Nov 5, 2001
Messages
4,340
Likes
0
#6
john: if you are using a 18.5 clamp shim (more like a washer) i cant see how putting anything above that will make that much difference- even if in theory the shims have got 0.1mm room to bend, thats not a lot on the yz forks- like running 0.5 vs 0.6 mm lift.

as for the twin chamber forks, i am a bit tentative on a RT check plate set up- my rm forks have gone from OK to terrible to excellent with only a couple of shim changes on the midvalve.
 

marcusgunby

Lifetime Sponsor
Joined
Jan 9, 2000
Messages
6,450
Likes
2
#7
I think we are getting confused with clamps and spacers-the clamp is the last shim in the stack that the stack bends over-in scotts case this is a 12.15, i think in scotts case i would increase this to a 12.25 or even 12.25(2)
to give the stack room to flex-alot depends on the stack build-a stacks with all 0.15mm thick shims will probably not bend over the clamp shim and touch the base-however a stack something like
24.1
22.1
20.1
18.1
16.1
14.1
11.2
will possibly bend over as the 14 is a big jump up from 11.

To be sure i would always use a clamp at least 0.25mm thick and often double them up to 0.5mm thick.
 
Joined
Jun 25, 2000
Messages
378
Likes
0
#8
The shim i was referring to is the one closest to the valve. It doesnt make sence if a thinner one would make the forks harder since in the chart they add more .15 shims to make it harder.

I would think the low speed stack acts when the oil is passing slow through the valve and when the oil is going through faster it starts to bend the high speed stack aswell. But is there any difference changing a big shim rather than a small shim or is it the total resistans the onlything that matters? Does the midvavle still have ANY affect after doing the "midvavle mod" recomended by racetech?
 

marcusgunby

Lifetime Sponsor
Joined
Jan 9, 2000
Messages
6,450
Likes
2
#9
The shims closest to the valve have a huge effect-a 0.1mm shim is three times softer than a 0.15mm-so if you are after a softer stack this is the way to go.
We were getting confused with the terms-in my example the 11.2 is the clamp and the 24.1 is the one that touches the valve.

On the question of big or little shims-the little ones are termed high speed and the large are considered low speed-so you need to decide which ones you are having problems with-high or low speed.And make the appropiate changes.

Once you do the RT mod the mid isnt considered part of the damping.
 
Joined
Jun 25, 2000
Messages
378
Likes
0
#11
Its now even softer but still im not happy with it. Its still harsh in the top stroke while the mid or last part of the stroke feels almost too soft. When i last from jumps it feels like it almost bottoming and doesnt absorb much. What can i do about it?

Its far away from the bikes i've ridden with good suspension. They feel almost "swampy" compared to mine, yet no hard landings. Like the '04 cr250f, really nice suspension. I want mine like that. They feel like its floating on the track while im bounching. Im gonna talk to a suspension company tomorrow and hear if im gonna get it revavled, front and rear.
 

marcusgunby

Lifetime Sponsor
Joined
Jan 9, 2000
Messages
6,450
Likes
2
#12
its still confusing what changes you have made, why dont you post the stacks you have used and how they felt and members can look over them to give guidance.
 
Joined
Jun 25, 2000
Messages
378
Likes
0
#15
Originally posted by marcusgunby
pyro could you list the stacks as i dont use the charts myself.
Sure, i just didnt have them in my head at the time.
All are 0.10mm thick from the vavle and out:
21
12
21
17
14
13
12
11
9