difference in valving yzf 250

Hi i would like to know if there i any difference in front for valving between the yzf 250 07 and 08

my yzf 250 2007 valving

32,12 (3)

16,12 added shim

32,12 (14)

30,12

28,12

26,12

24,12

22,12

20,12

18,12

16,1

14,25

14,25

11,12

my buddies yzf 250f 2006 front fork

32,12 (3)

20,12

32,12 (14)

30,12

28,12

26,12

24,12

22,12

20,12

18,12

16,1

14,25

11,12 (2)

14,12

18,12

20,12

22,12 (5)

I would like to know if they have removed 1 14,25 added the shims below?

or is that stock. i kow that the 20,12 between third and forth 32,12 is added.

is there any difference in stock shim stack between the 06 and 07?

thanks kristofer

Are these Euro stacks with the crossovers, you add them or is that stock?

my buddies yzf 250f 2006 front fork

32,12 (3)

20,12

32,12 (14)

30,12

28,12

26,12

24,12

22,12

20,12

18,12

16,1

14,25 alu shim

11,12 (2)

14,12

18,12

20,12

22,12 (5)

do you think about the shims after the alu shim? ive got 2 alu shims in my fork.. i know his fork have been revalved. anyone know the stock settings for these bikes?

Are these Euro stacks with the crossovers, you add them or is that stock?

hey steve:thumbsup: these are far from stock euro stacks.

kristofer, adding the cross over so high in the stack, or after 2 or 3 face shims acts as a bleed. i take it you run very little float on the mid?

both stacks are not standard, at least imho

07 stack:

transition (crossover) shim of 16 is pretty small and makes the LS very soft especially with a disabled bleed part.

At the bottom of the compression holder you can see 4 small holes. These are the bleed holes. The holes are covered with shims resulting in an delayed opening as you know it from the shims at the piston.

Those bleed shims which you can see at the 06 stack (everything below the 14.25) have been taken out at the 07 stack resulting in a permanent bleed of those bleed holes.

Reason for doing this is to make the fork much plusher at lower speeds - which it will be - with the downside of beeing more unstable at higher speeds.

The 06 stack is an 07 stack of a YZ450F with the 20.11 transition shim added. Not a bad thing to get it softer at very low speed.

what puzzles me are the 5 x 22.11 bleed shims. Not quite sure whether that's standard or not. Looks a little much (= stiff) to me.

So what does this mean?

the 07 stake is way plusher than the 06

okay then maybee i shoule change my 16,12 to a 20,12 or? where do you think i should put the shim? i want the fork to be soft at low speeds without bottomning.. I would like my stock front fork to work as my ohlins.. any suggestions what to do?

32,12 (8)

22,12

32,12 (8)

30,12

28,12

26,12

24,12

22,12

20,12

18,12

16,1

14,25

14,25

11,12

32,12 (3)

16,12 added shim

32,12 (14)

30,12

28,12

26,12

24,12

22,12

20,12

18,12

16,1

14,25

14,25

11,12

I would like to know why some people revalve their forks as this.

whats the difference between these stacks? would like to know the difference between putting the shim in the beginning of the stack or the middle? what about rebound? my is still stock. Do i need to revalve?

i'd say that with the second example, as i already stated, it's too soft for my liking.

The 16. crossover is at the very bginning of the stack and is very small.

That results in beeing very soft at very low speed but in then giving you a substantial resistance when hitting the remaining 14 x 32.

It makes the fork diving which may feel i little like falling through (eg when breaking) and then hitting a wall.

The first stack with a 22 in the middle makes the lowspeed softer but gives you a necessary resistance to keep the for up (in the stroke),

all in all it will feel smoother than the other example.

But you must not look at it isolated. The disabled bleed shims make the 16 crossover version even worse.

That's at least how i stack is working. More experienced people here may correct me.

Okay thanks i dont really know much about revalving, bur i would like to learn.

what about the smaller shims that comes after the 17 32,12... what are they for? Is there any need to revalve mid and rebound?

its called a cross over shim, it makes the stack bend easily at low fork speeds, as the stack can bend without the high speed part(below it) coming into effect.

I tought about the smaller shims that comes later in the stack.

any one that know the price for a dell taco kit?

any one that know the price for a dell taco kit?

IMO, the last thing you need to do is introduce another layer of stuff you don't understand...:busted:

Take a thin piece of wood like 3/8" plywood that is a one foot square. Lay it on a brick and stand on it with both feet aligned with edges of board. If you step on it across the narrow side of the brick the board will bend vary easily. Step on the long side of the brick and board will barely bend. That is a function of the "pivot" size (clamp shim).

Shim stacks work the same way. The board is the "face shims/low speed stack" (17x32) and the brick is the 11x.12.

If you add several pieces of plywood in progressively smaller squares (11"/10"/9"/8"/7"/6"/5" under the first piece, the whole deal will get nearly as stiff, when stepping across the bricks narrow side again, as it was across the wide side initially.

Clear as mud?

If I were adding a crossover to a late model bucket sized piston like everything since 03 comes with, I would use a 26 or 28mm shim in about the middle of the 32's...just don't like small dia crossovers as they are too effective.

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!


Register a new account

Sign in

Already have an account? Sign in here.


Sign In Now