I'm revalving my 45mm shivers on my 02 CR250

[Motosportz]

I've done these over the years, GGs and couple Huskys. Husky quality is better than GG version inside, but pull everything down and check your inner upper tube anodizing! I have a set of new 48 CCs on my Beta, anodizing shot in 30hrs. I don't think Marzocchi in general uses a good process, as almost everyone I have taken apart has had worn uppers. Also, perhaps its the light/flash, but you piston band looks very "gold" which could mean the teflon is worn through, not good.

I had a real good setup on a GG 250. Build the midvalve with a 1mm float, use a .15mm face shim, and regressive stack for support. The thing with mids is the ones that work the best don't last as long. The .15 thk face shim helps this. Also no mention of your rebound stack. In my experience with these there is inadequate rebound control, and what you may think is a compression harshness is actually a high speed rebound spike.

thanks for the time, nice info. The wear looked minimal and these forks feel nice and tight. Oil looked good. Mid valve bushing was uniform in color and did not look warn. Did not inspect tubes. other than everything look clean and in order.

- Wish I knew what springs were in this as i am leaving this out of the equation right now.

 

[Motosportz]

I'd expect it to be softer across the board, nothing drastic, but definitely noticeable. It will probably feel decent in the woods, it's not going to have a ton of bottoming resistance on big hits but that's probably fine for where you ride. If I had to guess it's still going to be a bit harsh on some embedded-rock type hits, depending on where you set the clickers. I'd set the clickers closer to the middle to start, if you open them way up I think you'll get a lot of chassis pitch. The bleed ports on those are pretty big, which is nice because you get a lot of adjustment range, but if you run them full open you get a lot of stack bypass.

yep, thats about what it did. Did not feel harsh but the rear bucking makes it hard to completely assess. Felt good over embedded rock which was a nice surprise. Did a few smaller woodsy jumps and seems to land nice and have a smooth stroke on landing. Was using slightly more travel than my 2 buddies is it is using the stoke but nothing drastic.

 

[Kyle Tarry]

Dude, pull that shock off and open 'er up. IMO, shocks are easier than forks. I assume that has the older small body Sachs, same as my brother's TE410...

Let's see what's in there, but you'll probably want to pull out a face shim or a couple, go smaller on the clamp (18mm will probably work well), and possibly go smaller on crossover. Would be interested to see how many face shims and what thickness the HSS is in that.

 

[Motosportz]

Dude, pull that shock off and open 'er up.

thats the plan

 

[Phaeton]

Subscribed. Kyle has been a wealth of information. Pics, vid of the rear revalve would be great.

 

[Motosportz]

I can snap a few pix but suspension is always an oily job and not going to try to take vids. Shocks are pretty simple.

 

[Kyle Tarry]

Subscribed. Kyle has been a wealth of information. Pics, vid of the rear revalve would be great.

Need to give credit where it is due, Motorhead has been a great source of knowledge to me (and others as well). The DIY Sachs revalve thread and its participants also helped motivate me to get into this stuff.

I won't claim to always be right on stacks, but if we all share information and have a conversation, it benefits everyone.

 

[MOTORHEAD]

Thanks Kyle.

It would appear from the pix that the rebound side is set up with a check plate and the compression side has a shim stack. I don't remember 45 zooks being set up that way, but they might.

To convert the compression side to a check you basically just need to replace the shim stack with one thick shim.

 

[Motosportz]

I won't claim to always be right on stacks, but if we all share information and have a conversation, it benefits everyone.

I have done some revalving in the past, used to be kinda into it. I dont know a ton about it but love making progress especially with suspension and bike setup as i find it very rewarding. Thats the reason I posted here as well and hope it helps others set their bikes up better for them as I know how much difference setup makes. I'm pretty particular on bike setup and how it feels and lube my levers, kickstarter, footpegs before every ride so they run smooth. I hate getting on a bike that does not work smoothly and for me. Fun stuff.

 

[Motosportz]

Thanks Kyle.

It would appear from the pix that the rebound side is set up with a check plate and the compression side has a shim stack. I don't remember 45 zooks being set up that way, but they might.

To convert the compression side to a check you basically just need to replace the shim stack with one thick shim.

Thank you for your input. I did one fork at a time which I'm glad i did because i had the mid vavle upside down after reassembly on the first one. Still looks upside down to me now. Trying to better understand how this all works.

 

[Kyle Tarry]

It would appear from the pix that the rebound side is set up with a check plate and the compression side has a shim stack. I don't remember 45 zooks being set up that way, but they might.

To convert the compression side to a check you basically just need to replace the shim stack with one thick shim.

It's a goofy setup I've seen on these before. I think it's a check plate setup, basically, except they put more than one shim in the check plate stack. Don't know why, maybe they were trying to get the float down for some weird reason. Kelly said that he measured the float at ~2mm, so the shims won't really be playing a part in damping anyway.

My guess is that the rebound is a stack of a few face shims, and then a clamp. My 610 was something like 23.1x6 and then a small diameter clamp; I bet this is similar, but with less shims. I think it's dumb to build these without a taper (puts more stress on the shim), but it seems common.

 

[GMP]

Thanks Kyle.

It would appear from the pix that the rebound side is set up with a check plate and the compression side has a shim stack. I don't remember 45 zooks being set up that way, but they might.

To convert the compression side to a check you basically just need to replace the shim stack with one thick shim.

Wouldn't work very well at all like that. I think what looks like a thick checkplate shim on the rebound side is the typical stock Zoke setup of 2 or 3 face shims, no progression, and a clamp. Piston port area would affect high flow rates(speed), but lower to mid speeds where you want the valve in play should still have stack influence. I've changed MV face shims on Zokes that were slightly fatigued so they are flexing and doing their job despite what the piston looks like. I think a check plate would be a step backwards considering what is trying to be acheived here. JMO.

 

[GMP]

Mic and list you mid stack and I'll post something to try. Try this for your rebound, that stock setup lack control, especially if your fast and run stiffer springs:

<piston>
22 x .1
22 x .1
19 x .1
19 x .1
18 x .1
17 x .1
15 x .1

 

[Motosportz]

Here is the mid valve info. I still think the whole thing looks upside down. Seems like the "stack should be on the end and the check p[late (4 shims of equal sizes) should be on the rod side no? seems looking at flow that how it should happen. Confused.

Edited now that I know what I am talking about...

rebound stack - (5x) 22.03 - .110 shims

mid valve:

22.98 - .220
22.01 - .310
19.99 - .300
18.97 - .300

with slightly more than 2mm float on soft spring.

Let me know what you think.

Forks seem to be a good improvement over where i was so it is a step in the right direction. The Shock feels like crap in comparison so need to do that before I can fully evaluate the front as it back is bouncing around and mucking up my feel for the front. What kind of stack would work well for the rear as a starting point. I think I have a good idea what I want to do (similar to the front) but would be good to have your thoughts. Hope to do this today. also whats the down side of using air instead of nitrogen ont he shock if i cant find someone local to charge it ASAP? My local suspension guy says nitrogen is better but air will work in a pinch without issues.

 

[Kyle Tarry]

You've got your two midvalve stacks backwards. The real question is, are they just backwards in your head, or are they backwards on the fork?

The "nut end" of the midvalve is the REBOUND stack. Under rebound, the fork cap is yanking this whole assembly up through the cartridge, and oil is flowing from the rod side of the piston to the nut side. There should NOT be a spring on this stack, it should be clamped tightly. Your (5X) 22x0.1 shim stack is a very typical Marz Shiver 45 rebound stack. You could replace this with the stack that GMP suggested, would probably work nice.

The "rod side" of the midvalve is the MIDVALVE COMPRESSION stack. On these forks, it's generally what people call a "checkplate" setup, basically a check valve; a spring holds a shim against the piston under rebound so the oil can't bypass the rebound stack, and then under the compression it opens "a lot" to let oil through freely. MX bikes and more modern woods bikes use a standard tapered shim stack here with less float to get more damping (and more tunability). You can remove the stock shims here and build your own midvalve stack, if you wanted. For your bike and use, I probably wouldn't bother. For a bigger bike and more varied use (like my 610), it works really well to do a "real" midvalve.

 

[Motosportz]

Mic and list you mid stack and I'll post something to try. Try this for your rebound, that stock setup lack control, especially if your fast and run stiffer springs:

<piston>
22 x .1
22 x .1
19 x .1
19 x .1
18 x .1
17 x .1
15 x .1

For reference I am a top 3 B class or mid pack A class when I race.

 

[Kyle Tarry]

Forks seem to be a good improvement over where i was so it is a step in the right direction. The Shock feels like crap in comparison so need to do that before I can fully evaluate the front as it back is bouncing around and mucking up my feel for the front. What kind of stack would work well for the rear as a starting point. I think I have a good idea what I want to do (similar to the front) but would be good to have your thoughts. Hope to do this today. also whats the down side of using air instead of nitrogen ont he shock if i cant find someone local to charge it ASAP? My local suspension guy says nitrogen is better but air will work in a pinch without issues.

Is the shock bad on comp only, or also rebound?

Open it up and post up what's in there, and we can make some suggestions. I can post up some stuff I've done on other bikes, but it's hard to say what will work for you without knowing what's already in there. However, here are a few things to look for:

-2-stage stack. Crossover of 26-30mm.
-Only 2-4 38x0.20 face shims before crossover.
-Clamp on 18mm shim

My guess is that, after you open it up, you're going to want to put a smaller clamp in it (very important and effective) and possibly change the number of face shims and/or crossover.

You can definitely use air in the short term. It also lets you test out different valving, without needing to pay to have it charged every time. Once you get the valving down, I'd put nitrogen in it.

 

[Motosportz]

You've got your two midvalve stacks backwards. The real question is, are they just backwards in your head, or are they backwards on the fork?

The "nut end" of the midvalve is the REBOUND stack. Under rebound, the fork cap is yanking this whole assembly up through the cartridge, and oil is flowing from the rod side of the piston to the nut side. There should NOT be a spring on this stack, it should be clamped tightly. Your (5X) 22x0.1 shim stack is a very typical Marz Shiver 45 rebound stack. You could replace this with the stack that GMP suggested, would probably work nice.

The "rod side" of the midvalve is the MIDVALVE COMPRESSION stack. On these forks, it's generally what people call a "checkplate" setup, basically a check valve; a spring holds a shim against the piston under rebound so the oil can't bypass the rebound stack, and then under the compression it opens "a lot" to let oil through freely. MX bikes and more modern woods bikes use a standard tapered shim stack here with less float to get more damping (and more tunability). You can remove the stock shims here and build your own midvalve stack, if you wanted. For your bike and use, I probably wouldn't bother. For a bigger bike and more varied use (like my 610), it works really well to do a "real" midvalve.

Shit, the mid valve is backwards. I thought so and it did not make any sense to me but not knowing I put it back in the way it came out even though it seemed wrong to me. Right now the check plate is on the nut and and clamped while the rebound stack is on the wrong side (rod side) and floating. Guess I get to take them apart again. I'm sure this is why it feels somewhat divy in the front and I was turning the clickers in. Also probably why it is very good int he rocks as it can react very quickly with all the float and soft stack pushing oil to the base valve. Oh well, I'll be very good at all this when I get done (cup half full :>).

 

[Motosportz]

You can definitely use air in the short term. It also lets you test out different valving, without needing to pay to have it charged every time. Once you get the valving down, I'd put nitrogen in it.

Exactly what I was thinking / hoping. Thanks.

 

[Kyle Tarry]

Hold on there! Your description of where the shims are sounds right, just your terminology is wrong, I think. It should look like this:

Damping Rod
Spring
19x0.3
20x0.3
22x0.3
23x0.2
Piston
22x0.1 (5X)
Nut

I think this is how you have it...

The 5x22x0.1 stack is the rebound stack. The stack of 4x thicker (0.3mm) shims and the spring is the "check plate" or "midvalve compression" stack. If you swap the two stacks, the bike will feel REALLY shitty, because those thick shims on rebound would be a disaster.

Edit: In case you're not sure which way the piston goes, the big ports go towards the "top" side (the rod side) and the small ports go towards the rebound side (nut). It's probably the same piston as the base valve, just flipped over. This looks correct in your picture, but just wanted to add it for completeness.