“Bleed” stack on Showa twin chamber forks.

[trialsmasta]

I have a 2003 RM 125 and I’m in the process of putting some Race Tech gold valves in. The instructions aren’t very clear and the video is circa early 90’s :ahhh: . Hence doesn’t show craaaaap about twin chamber forks. I’ve taken my forks apart several times to replace seals, so no big deal. Underneath the LS and HS stack is a spacer and some shims ( ~ 12mm in diameter). Well under that spacer is a shim stacks with covers up some sort of a bleed or check valve. What does this stack do? The race tech instructions make it sound like there shouldn’t be a stack there. At this point I assume the print something to the effect “not all stacks will look like the incompletely labeled diagram shown” applies to me. Should I be concerned about leaving this stack in. The stack is as follows.

16x.1
14x.1
12x.1
10x.1
9x.1
SPACER & Shims ~ 12mm dia
HS stack
LS stack
Stock valve

 

[marcusgunby]

I dont think you need bleed stacks on lighter bikes like the 125, the kxf 250 doesnt have them , but for say a rmz450 or cr450 i think they are usefull.

 

[trialsmasta]

Why do you say that and what would you put in place of the bleed/blow of valving?

 

[WhiPit]

Marcus, I tend to agree with you. I've often wondered why they (Showa/Suzuki) opted for this on a bike like the RM-125. I think it helps on 4-strokes which can generate a lot of chassis pitch....not so sure it's effective on a bike like a 125 2-stroke.
Trials - this is the Lo-Speed shim stack. Honda's from '03 to today have them (although with a huge side bleed). If you're doing MX, just leave it alone. If you were doing woods (or you are very light in body mass) you could flip the stack over. HOWEVER, I'm not a Race Tech guy, so I don't know how it would affect the RT system of valving, nor do I know what RT recommends.

 

[trialsmasta]

I left that stack alone, and I left the mid valve alone too. I havn't ridden the bike yet, but I'm not as amped as I orginally was when I was putting the GV in. Initial push test in the garage it dosn't seem as plush as my stock suspension.