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2014 YZ450f shim stack advice

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Hey guys I'm after some advice on this topic.

Firstly where talking about the euro spec model here. 

I've done a lot of testing and a few re-valves from a tuner, but its still not where I want it so I'm capable of changing it myself and want to try that, but some expert advice/opinions would be much appreciated, (Mog & Vietze) always enjoy reading your stuff.

Stock springs, FC high speed adj spring, semi pro/fast/expert off-road, cross country rider, weight without gear 80kg (176 lbs).

Riding style & Terrain: I prefer a lower rear end that doesn't push the front, I stand a lot and the terrain is very mixed sand, mixed soil, tree roots, rough to very rough.

If any one has some good idea's for Fork & shock feel free to chime in but I'll start with the shock and address that first.

 

Stock shock shims are as follows.

 

Comp:

44.25 *7

42.20

40.20

38.20

36.20

34.20

32.20

30.20

28.20

26.20

24.20

23.30

Rebound:

40.20 *4

28.11

40.25

38.30

36.30

34.30

32.30

30.30

28.30

26.30

25.30

 

Modified shock shims as follows:

 

Comp:

44.25 *6

34.15

42.20

40.20

38.20

36.20

34.20

32.20

30.20

28.20

26.20

24.20

22.30

Rebound:

40.20 *4

28.11

40.25

38.25

36.30

34.30

32.30

30.30

29.30

28.30

27.30

26.30

25.30

 

What I'm finding is the shock doesn't initially want to squat down especially on roller type bumps, but then once you get it moving it has no guts and falls through and then wants to spit me.

In my mind it is still to stiff in the LS comp but then to soft in the HS comp, as for the rebound the HS has been stiffened/slowed which in my mind wouldn't be help traction on choppy acceleration bumps or tree roots.

 

I'm thinking I want to put the rebound back to standard, then build the Comp as follows but my only concern is it will make it to harsh on square edge acceleration chop and tree roots which it isn't even great on at the moment.

44.25 *5

34.15

42.25

40.25

38.25

36.25

34.25

32.25

30.25

28.25

26.25

24.25

23.30

 

And yes I've done plenty of testing, sag,springs,clickers etc just hard to list all of the that.

 

Maybe to get that initial movement I need even less LS or a different Crossover size/placement? and then a crossover in the HS to help with the roots?

I dunno I'm lost, please help.

 

 

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Hey guys I'm after some advice on this topic.

Firstly where talking about the euro spec model here. 

I've done a lot of testing and a few re-valves from a tuner, but its still not where I want it so I'm capable of changing it myself and want to try that, but some expert advice/opinions would be much appreciated, (Mog & Vietze) always enjoy reading your stuff.

Stock springs, FC high speed adj spring, semi pro/fast/expert off-road, cross country rider, weight without gear 80kg (176 lbs).

Riding style & Terrain: I prefer a lower rear end that doesn't push the front, I stand a lot and the terrain is very mixed sand, mixed soil, tree roots, rough to very rough.

If any one has some good idea's for Fork & shock feel free to chime in but I'll start with the shock and address that first.

 

Stock shock shims are as follows.

 

Comp:

44.25 *7

42.20

40.20

38.20

36.20

34.20

32.20

30.20

28.20

26.20

24.20

23.30

Rebound:

40.20 *4

28.11

40.25

38.30

36.30

34.30

32.30

30.30

28.30

26.30

25.30

 

Modified shock shims as follows:

 

Comp:

44.25 *6

34.15

42.20

40.20

38.20

36.20

34.20

32.20

30.20

28.20

26.20

24.20

22.30

Rebound:

40.20 *4

28.11

40.25

38.25

36.30

34.30

32.30

30.30

29.30

28.30

27.30

26.30

25.30

 

What I'm finding is the shock doesn't initially want to squat down especially on roller type bumps, but then once you get it moving it has no guts and falls through and then wants to spit me.

In my mind it is still to stiff in the LS comp but then to soft in the HS comp, as for the rebound the HS has been stiffened/slowed which in my mind wouldn't be help traction on choppy acceleration bumps or tree roots.

 

I'm thinking I want to put the rebound back to standard, then build the Comp as follows but my only concern is it will make it to harsh on square edge acceleration chop and tree roots which it isn't even great on at the moment.

44.25 *5

34.15

42.25

40.25

38.25

36.25

34.25

32.25

30.25

28.25

26.25

24.25

23.30

 

And yes I've done plenty of testing, sag,springs,clickers etc just hard to list all of the that.

 

Maybe to get that initial movement I need even less LS or a different Crossover size/placement? and then a crossover in the HS to help with the roots?

I dunno I'm lost, please help.

 

 

Since the Yamaha KYB suspension is generally regarded as the best stock stuff going, I would keep the basic stack arrangement.

 

Put the stack back to stock and remove 3 x 44x.25's, the .25 shims are doing the majority of work so making changes here will net the biggest results.

 

Note the crossover is'nt needed, you want the stack to be firm but compliant, all the crossover does is eliminate the support of the .20 shims after it. The stack needs to provide enough resistance against fluid flow through the valve to keep the shock up in the stroke but then open just enough when required.

 

As far as the rebound goes stiffen it up, try adding 4 or 5 40 x .20 shims and increasing the crossover to a 32  x .11.

 

Ultimately what you want the shock to do is compress somewhat easily but then have controlled extension. If the shock tends to pack you can use the rebound adjuster to make it a bit faster.

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That's a tricky one

Here is a 10 450

44-0.2 (13)

34-0.15

44-0.2

42-0.25

40-0.25

38-0.25

36-0.25

34-0.25

32-0.25

30-0.25

29-0.25

28-0.25

27-0.25

26-0.25

25-0.25

24-0.25

23-0.25

22-0.25

21-0.2

reb

40-0.2 (4)

29-0.11

40-0.3

38-0.3

36-0.3

34-0.3

32-0.3

30-0.3

28-0.3

25-0.2

It looks like a clone of yours but yours has a bigger clamp which will have a big effect , I think your stack with the smaller clamp and a smaller crossover like a 32.15 could work

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