Stock shim stacks for the Marzocchi Shiver 48 on 4Ts

[Leon_RR250]

Glenn,

Good to hear you found a solution to your problem. I am still wondering why you got this kind of problem within so short amount of time. Have you discussed with Beta for this issue? My Marzocchi has been used for 80 hours by now and it is like new internally, I mean the coatings. Of course the beautiful red anodizing is not strong and there are lots of scratches already around the clamping areas...

Leon

[GMP]

After looking at everything in detail, my feeling is that the anodizing is just not that great consistantly. Same inner and outer. Cosmetic color T2 anodize is done at a lower current, higher temp, and yeilds a thinner layer. I too had a grain of sand stuck on the top edge of the lower triple and it easily scratched off the red coating when I twisted the fork out, very thin. Also when I buffed the internal bore it was being removed with aluminum polish. I originally thought there may have been debri in the fork but that is unlikely being it had two prior oil changes, what I found came from the upper tube. The bushing on the affected leg had a slight twist so its possible it did not float properly in the land of the lower, and grabbed the inner wall of the upper on its edge. The bore of the right side upper looked like a cylinder that had a piston seizure. Other tube also had early stages of wear but no scoring. May just be a combination of things. Yes, many (most) have no issues but it is happening to some. Keep everything clean and serviced, and watch the oil. The bad thing is it pushes the fouled oil into the cartridge where it can do more damage. We will see what happens, hopefully it will be servicable for the year.

[Leon_RR250]

Hi!

Finally yesterday I could find out about the valving of the midvalve and rebound. And I was happy to see what I was expecting to see, that big part of the problem I had in technical woods was due to the midvalve.

I repeat first the comp stack from the first post in this discussion (earlier you can see my comp stack... and using wrong oil...) and then I list what I found yesterday.

Comp stack
32 - 0.1mm (x10)
20 - 0.1mm (crossover)
32 - 0.15mm
30 - 0.1mm
29 - 0.15mm
28 - 0.15mm
26 - 0.15mm
24 - 0.15mm
21 - 0.15mm
20 - 0.15mm
18 - 0.15mm
16 - 0.15mm
14 - 0.15mm
12 - 0.15mm
11 - 0.2mm .

Midvalve stack:
20 - 0.1mm (5)
18 - 0.15mm
16 - 0.15mm
15 - 0.15mm
12 - 0.15mm
11 - 0.2mm

Rebound stack
20 - 0.1mm (3)
12 - 0.1mm
20 - 0.1mm
17 - 0.1mm
14 - 0.15mm
11 - 0.2mm
11 - 2.5mm

I left the rebound stack (at least it does not have a bleed shim) as it is for now and I proceeded with the following stacks considering the feedback from Glenn and what I have actually felt on the bike until now. Please comment. Again the same 340ml of oil in the outer chamber and the same mix of Red Line oils for the correct centiStoke value in both chambers. And 2 turns in for the PFP preload.

Comp. stack:

32 - 0.1mm (10)
30 - 0.1
28 - 0.1
26 - 0.1
24 - 0.1
22 - 0.1
20 - 0.1
18 - 0.1
16 - 0.1
14 - 0.1
12 - 0.1
11 - 0.2mm.

Midvalve stack:

20 - 0.1mm (4)
11 - 0.2mm
15 - 0.15
16 - 0.15
18 - 0.15 .

Testing on Saturday. I will let you know how it feels of course. Any comments are welcome!

Leon

[GMP]

Leon,

Looks like a good start. If its still a bit harsh I'd trim down the comp stack a little, make the taper a little steeper toward the clamp, but its just a guess at this point as the 4stroke is much different. Just keep in mind that this fork seems to get away with lighter specs than you would think. Now that your PFP adjusters work play with those and note results as well. Good luck keep us posted!

[Leon_RR250]

Thank you again for the advice! I am hoping that I am very close for the midvalve and rebound stacks so I won't have to disassemble these again. The comp stack is much faster to recheck and anyway it seems this fork likes fresh oil after max 15 hours. Also I read in the manual that actually 1 turn of PFP is about 0.5mm so the 2.8mm washers I used were too much, adding to the harshness I felt in the rocks and roots. I will know much for after Saturday's ride. I am just searching for a good compromise between sand whoops and woods. I liked the fork last time in sand.

Leon

[dirtbird]

Leon from my experience even half turn on the PFP has a noticeable effect. 2.8mm was like having PFP at max preload (6 turns) which should be ok for ....... Supercross .

I second GMP on that this fork can use lighter valving than usual (found out in-directly though).

[Leon_RR250]

Thanks dirtbird for the additional info! I am really waiting for the testing on Saturday... We have 4 cm of (new, powder like) snow and all the stones and roots are just there waiting for me. I will use a different tire with short spikes than the Metzeler six days fim but still I should be able to understand how the fork has changed/improved.

Leon

[GMP]

Remember that PFP starts out with 7mm preload on the 2kg/mm spring and goes up from there. This is different than say a KYB that starts at 0. Why? It addresses cavitation in the begining of the stroke, where there are a lot of short fast movements. To fully understand the function of the PFP fork, you have to think about it in both static and dynamic terms. Static being just the effective spring rate and preload added to the overall, dynamic being the effect of the added backpressure on the valve stack. Now that I have wrapped my head around it I understand why it works so well with that big piston, light stack, and all that bleed.

[dirtbird]

Thanks Glen, great info.

[Leon_RR250]

Hi!

Yesterday I tried the new valving but not in our local very technical forest but during a club race in mainly sandy forest. All the riding buddies wanted to go there... Anyway, with the clicker settings 20 out for both comp and rebound and the PFP 2 turns in, as the manual suggests, it was a blast to ride even in -15 C. I was trusting the fork 100% all the time. It was good in whoops in soft sand, good in very high speed with small bumps/holes, good in very sharp braking bumps and there was a section with tree stubs and roots that I had no problem at all. The fork was at the same time stiff and smooth in a very nice way and using when needed the available stroke. Somehow much better than before and I didn't feel at all to play with the PFP or the clickers. The testing on rock gardens and other trash still needs to be done soon but I think I am at least fine with the midvalve and rebound stacks.

And I am not searching anymore for the stock 4T stacks (if they are different than the 2T stacks....) since from now on it is about fine-tuning for me. The only reason that it would be good to have the stock stacks is about preparing the bike later for selling it forward...

Thank you Glenn again, and all others, for your help! I will update soon when I try it in our local technical forest..!

Leon