cr rear shock valving

[bjalbert]

Hey guys,

Ok I am about to revalve my shock on my 2001 cr 125 due to the stiff feel it gives. the rear of the bike dances around alot on square edge accel. bumps. and does not seem to get good traction during this time. I have tried everything except valving, so far the best thing that has helped has been to turn the clickers to full soft.

A friend told me that all I would have to do is put a smaller dia. crossover shim and that should give me a plusher ride and make the rear contour to the terrain better.

now the question is will that give me what i need or do I need to take out some of the lsc and lsr as also suggested. I have not pulled it apart to see what is in there yet.

Which has a bigger effect smaller dia. shims or thinner shim for removing the stiffness of the stack, or does each one play its on part in getting the correct stack.


Bjalbert
2001 Honda CR 125

 

[marcusgunby]

bjalbert a smaller cross over shim will have a small overall effect.

After working on the 2002 forks the advice i can giveis it to make big changes otherwise when riding would think you havnt done anything.

Changing the crossover would be my answer if the basic amounts of LSC were close.

I tend to take shims out as for a novice suspension builder its easier than ordering up say 12*0.15mm shims to replace the 12*0.2mm ones in there.

There is a stiffness comaprison between 0.1mm and 0.15/0.2/0.25/0.3 but i cant remember it.I like to stick to 0.2mm shims on LSC/LSR as then its easier to compare one shock setting to another.

A tip for you is to try to get hold of the std shock valving of a 99 Cr125-that had a real nice plush feel.This will give you insight into how different(stiff) a 2001Cr125 valving is.

 

[bjalbert]

Thanks Marcusgunby,

Thanks again for the help one more question to understand more on how stiffness or softness is aquired. Is it better to reduce the diameter of the shim or the thickness to obtain the desired result or does it matter is it more what you have available at the time. I have alot of extra shims. I am just trying to get an idea of the relationshoip between the thickness versus diameter. Also what is the limit for big changes. If I remove 2 shims 5 shims what generally is a good starting point or is that something you find out over time from experience.

Thanks Bjalbert
2001 Honda CR 125

 

[marcusgunby]

Im not really a expert on shim sizes and how big an effect it has,all i can say is a smaller shim allows the others above it to bend over easier so the stack becomes softer and vice versa.There are many ways to reduce stack stiffness/properties and thats i guess where the skill is.I have learnt most by riding various bikes and getting a feel for how they are -then stripping the shocks/forks and getting all the shims sizes and seeing how it reltes to the feel on the track.You soon see trends and what works.This applies well to the KYB shocked bikes like the KX/RM250/CR125/YZ they do have different linkages but they arnt that different so you can put a YZ stack in a CR and it will work-it may not be perfect but its all learning.

I like to keep this kind of shims stack

LSC made up of 0.2mm shims
Cross over
smaller crossover
High speed made up of 0.20s
high speed made up of 0.25s

I use 2.5wt ,silkolene 2.5 wt is a resonable choice.
My next hint is i like your second suggestion best.
With the Cr shock it has so many shims i just remove lots.
Remember big changes on LSC less so on HCS and as for LSR well really go to town on that.
Try to keep the shim stacks looking like the originals(in shape) but less of it ie
have a stack of LSC then the cross overs then have a progressivly smaller high speed stack.