valving?

[rpxtreme03]

i have a crf250r that the suspension was set for a 185# class A motocrosser im a 170# class B harescrambler. i set the springs back to stock as race tech say but it still beats the helll outta me i know that is probably shimmed heavy as hell as tbt set it for him. so what do i do to my shims to fit my riding and weight? also should i change anything else while im in there? obv. the seals and bushings but what about the rebound screw and oil level? ill let you know what i have for shims soon

[rpxtreme03]

also I live in upstate ny so mostly loamy clay with quite a bit of rocks and roots in the woods. The bike seems to deflect off most everything the tires touch not like its rebounding too fast just not absorbing anything

[mog]

we need to see what you have now.

[rpxtreme03]

yea i figured that...been a little swamped with work and school so ill get it apart as soon as i get time and post my stacks. just figured id see what i could get for info befor hand. btw can any one explain to me the different stacks for the forks. base valve and mid valve and rebound stacks obv. i get the rebound but the base and mid. what do they effect? how do they work? just trying to soak up as much info as possible befor diving in. thanks ive been looking at all sorts of other post on here just kinda getting a general sence for these things. ive do the springs and oil levels and n2 pressures and rebuilt forks and shocks plenty of times never done anything with the stacks though.

[rpxtreme03]

correct me if im wrong but the shock just has a rebound and a compression stroke valving right? generaly the rebound on both should be basicaly left alone is the impression i seem to be getting also. i mean how much can you realy improve it to fit your riding that you cant do with clickers? any advise or input out there?

[mog]

the questions you ask are huge , look at the dogger thread , that's got tons of info

[rpxtreme03]

lol sorry im just trying to learn and thanks i will.

[kawamaha]

.. i get the rebound but the base and mid. what do they effect? ...

really huge questions...

but at least what is a basevalve for could everyone test by himself.

take a twin chamber fork cartridge and remove the basevalve.

now compress the rod as fast as you can. you will see that there's almost no damping, though the midvalve is not removed.

the oil doesn't flow through the midvalve. instead, it creates a vacuum at the bottom and just rises the oil level above the midvalve.

a basevalve creates a pressure against the oil above the midvalve...

[kawamaha]

...i mean how much can you realy improve it to fit your riding that you cant do with clickers? any advise or input out there?

the rebound is stiff compared to compression. so the clicker has a huge effect.

the compression clicker has by far less effect and there's almost no effect at HS damping

[rpxtreme03]

thanks. that diy article by the dogger is amazing. so much info in there!

[rpxtreme03]

so i think what i have found is as follows.

30x.43 (REBOUND)

piston

30.1(15) (LSV)

24.1 (HSV) (all the way down to base plate)

29.1

28.1

27.1

26.1

25.1

24.1

23.1

22.1

21.1

20.1

base plate

16.1(8) (LOW SPEED ADJUSTMENT SHIMS)

16.2

16.1

11.2

12.1

13.1

14.1

15.1

16.1

What are the low speed adjustment shims? what are they for? i dont seem to see them in any one elses stack on here.and how do i get into the mid valve? so many questions some one please answer me lol

thanks all =]]

[kawamaha]

What are the low speed adjustment shims? what are they for?

question 1: some oil goes via the bypass (controlled by the clicker).

usually its just a variable orifice, but on some forks there's an extra shim stack to control this.

[kawamaha]

2... how do i get into the mid valve? so many questions some one please answer me lol

thanks all =]]

didn't you find that in doggers thread?

after removing the base valve assembly and the jam nut at the end of the rod you can push it through the cartridge.

on showa 12mm rods its highly recommended to wrap some teflon around the threads.

on KYBs I don't do that because its a 12mm thread and a 12.5mm bore. but if you want to feel save...

[rpxtreme03]

nope i didnt find that. so basicaly that extra stack is just sumthing that tbt did to stiffen this up for the rider who had it befor me? if i understood you correctly. does it usualy have no stack in there at all?

[kawamaha]

nope i didnt find that. so basicaly that extra stack is just sumthing that tbt did to stiffen this up for the rider who had it befor me? if i understood you correctly. does it usualy have no stack in there at all?

what I mean is that some bikes come stock with a "bleed stack", some don't have them stock

[rpxtreme03]

ok. does anyone know if a crf250r has one stock? could it possibly be something that tbt put in here to stiffen it up for the last rider honestly that base valve compression stack, while it is quite stiff for woods i dont think it should be deflecting everything like it does. im wondering if tbt put it in there, because the rest of the stack is nearly stock.

[kawamaha]

.. does anyone know if a crf250r has one stock?

there is no "a crf250". the stacks differ from year to year. so eg a 2007 crf250 has a bleed stack....

[rpxtreme03]

it is a 2006

[rpxtreme03]

btw thanks for all your help between you and doggers post i am learning a lot and i have to thank you for turning me onto doggers thread as well.

[kawamaha]

no problem - the 2006 also has a bleed stack

https://www.thumpertalk.com/forum/showthread.php?t=789497&highlight=crf+2006+stack

Edited October 26, 2011 by kawamaha