What does this look like? Shim stack

kevinmfaust

Member
Oct 27, 2003
11
0
I purchased an 03 RM 250 for the woods and the guy I got the bike from said it had been revalved for the woods. Harsh on the small stuff. I am a woods rider.

1 24x.15
2 24x.15
3 24x.15
4 15x.15
5 22x.15
6 18x.15
7 18x.15
8 11x.25
9 18x.40
10 18x1.0
11 18x1.0
Kevin
 

russ17

Member
Aug 27, 2002
301
0
I think this was the stock stack so you can compare.

6-24.15
22.15
22.15
18.15
18.15
14.15
11.25

You will need to give these guy's more info as far as weight ability and such.
 

russ17

Member
Aug 27, 2002
301
0
I would check and see what spring rates you got in there. Or check with the person who you bought the bike from. They might be able to give you some insight on what else was done, such as if the midvalve was converted to a check plate. Find out as much info as you can.
Then we can start giving you some sort of direction.
 

ruddycooter

Member
Jun 21, 2003
11
0
Make life simple. Find out the stock base valve stack, and half it. Find out the stock midvalve, and half it. Run the stock spring (even though rider wt is 220) Start with stock oil level and see what happens. Add oil to control bottoming and go from there.

Signed,
Absolute beginner
 

chrismxer

Member
Aug 17, 2005
69
0
Kevin considering your weight I would say you need a little stiffer springs, a valve stack and oil level closer to stock. Mabey a 2 stage stack depending what you like and how hard you hammer, 44 fork springs with a little preload and something like a 5.1 - 5.2 for the rear. That would be a more solid base to work from.
 

kevinmfaust

Member
Oct 27, 2003
11
0
I am doing enduro HS riding and the spring calculator at MX Tech says I have no problem with the springs and when I was riding the bike stayed up in the stroke and no bottoming. I am staying with springs for now.

I learned a lot from the men at KTM Talk. My last bike was a 300 EXC so I have been on there for a while. Hats off to them, they are very generous with there wisdom.

I learned that there are draw backs to a shim stack design. My bike is excelent on all terrain but the 3" root, rock etc. I want something like blow off help. The problem is that the low speed part of the valve has to work to engage the high speed part of the stack. Boo Hoo. I can see the value in the Nost valve now. I am going to try this for a stack.
24x.10x 8
24x.15x 8
24x.15x 8
15x.15x 8
22x.10x 8
18x.10x 8
16x.10x 8
14x.10x 8
11x.25x 8


Old stack
24x.15
24x.15
24x.15
15x.15
22x.15
18x.15
18x.15
11x.15
Still looking for advice.
Kevin
 
Last edited:

marcusgunby

LIFETIME SPONSOR
Jan 9, 2000
6,450
2
i would not replace the 18.1 16.1 and 14.1 in the original hs stack with a 18.1(*2) it may not achieve what you want.

I would also remove shims in the hs stack or you may not actually reduce hs at all.
 
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