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# Question on ID of shims on a Stack

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This is pertaining to the Mid Valve set up. Are all I'D measurements suppose to be the same for all three sections of the Mid Valve?

Meaning......are all 6mm ID's all together and all 8mm ID shims together?

Say for instance if it looked like this

What I am getting at is......can 8mm ID shims mix with 6mm ones? Or do all ID shims have to stay together with there ID sizes? Like all 6's with 6's. And all 8's with 8's?

10×30×6. Or can it look this. 10×30×6

16×15×6. 16×15×6

16×15×6. 16×15×8

18×15×6. 18×15×6

20×11×6. 16×15×8

Piston.

20×11×8

12×10×8

12×10×8

20×11×8

17×11×8

Spring

8×5.80×6

8×30×6

8×30×6

12×30×6

12×30×6

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They are grouped together by ID. On the compression side, your 8s are your floating shims. They float up and down on a post and are located right against the compression side of your MV piston. Your 6s are all together after your 8s. They don’t float.

So. Your first stack listing is correct, not the hypothetical one. Although, it’s interesting you have 12s between your 20s followed by the 17.

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They are grouped together by ID. On the compression side, your 8s are your floating shims. They float up and down on a post and are located right against the compression side of your MV piston. Your 6s are all together after your 8s. They don’t float.

So. Your first stack listing is correct, not the hypothetical one. Although, it’s interesting you have 12s between your 20s followed by the 17.

So you never put 8 ID shims where 6's go or vice versa? Do They all ways go 6's, 8's and 6 on the mid valve......all ways?

Thanks! BTW... you really explained the floating part good. I really understood that. Before I didn't really get what goat was on the mid valve. But after you detailed it I understand now.

Didn't know those 8id shims floated till now

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So you never put 8 ID shims where 6's go or vice versa? Do They all ways go 6's, 8's and 6 on the mid valve......all ways?

I hate to say things like “always” but I can’t think of a scenario where 6s and 8s would be blended together. I’ve never seen a situation where they have been and can’t imagine one. A six would not fit over the post, and an eight would wobble where the 6s fit.
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I hate to say things like “always” but I can’t think of a scenario where 6s and 8s would be blended together. I’ve never seen a situation where they have been and can’t imagine one. A six would not fit over the post, and an eight would wobble where the 6s fit.

Exactly what I was thinking! I just wanted to make sure. Thanks for clarifying that for me.
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Here is the Base valve stack I have in my 2015 YZ250 smoker.
Can someone tell what kind of stack this is by the measurements? I was using a 48kg spring on Left Fork and the Stock 44kg in the right Fork.

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It’s a two stage stack (24 crossover). How do you like the fork action?

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It’s a two stage stack (24 crossover). How do you like the fork action?

Fork action is pretty good I guess. I am running a 48kg spring in one fork and the other one is the stock 44kg.
With this valving here and the valving in the mid valve with both stock springs, it's seems a touch too soft. Too much down in the lower part of stroke.

I am working with Dave J. Of Smart Performance right now on it. He built me a kit to go in it.
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Here is the Mid Valve stack.
What does this tell ya?