Stock shim stacks for the Marzocchi Shiver 48 on 4Ts

[Leon_RR250]

That's a good point Glenn! I never thought about the float of the midvalve until now. As I remember I increased it by 0.25mm last time by removing completely two shims from the stack and yes now it is similar as for the 2T. I will add them back at the end of the stack only for the float decrease. I need to find the (mental) power to do it tomorrow evening before the practice on Thursday.

Leon

[GMP]

Stock float on mine is .75mm that I still run. I'd work between there and .5mm. Harshness and spikes are usually from the inability of the mid stack to flex adequetely for the flow involved. The stacks in our bikes are tame, if they were too stiff the 2strokes would suffer badly. Tightening up the float may help the low speed support without compromising the high speed.

[Leon_RR250]

I decided not to work on the valving just before the race. I will continue tomorrow with the same settings from the last round of the club race in our local known trail. I will go to 10 clicks out to see if it helps the fork stay higher in the stroke. All the tests until now showed that with 1,5 or now 1 turn in for the PFP the fork is easily using too much travel and becomes harsh if the clicker setting is not adequate. The midvalve float needs to be addressed (thank you again for this suggestion) since I don't use bleed shims and the comp stack is a normal single stage all the way down to the base shim.

My current conclusion is that this fork needs to be set-up super soft for the lighter 2Ts (especially in motion) and just normally (as, for example, for a KYB SSS) for the heavier 4Ts. Now again I would really like to see the stock stacks of the Race 4Ts. If they still have bleed shims then the PFP needs to be at least 3 turns in and maybe more oil in the outer champers will be needed. Or some other magic going on...

Leon

[Leon_RR250]

Hi!

Partly I was assuming correctly for the 4T if bleed shims were existing... All of a sudden it was confirmed by a Friend that the 4Ts use the same valving as the 2Ts. And this also corresponds to another thread in thumpertalk for this fork, discussed last year... Only the springs are much firmer (0.48s from 0.42) and they have 10ml less oil than the 2Ts in the outer chamber (due to the difference in springs?), at 370ml, 30ml more than what I had. Below the new stacks I created yesterday. Slightly stiffer because of the thinner base shims. I did not have enough 11 - 0.2s, but I do not think it will affect negatively the heavier 4T... Also I decided to decrease the float on the midvalve compared to the 2T setting.

Comp:
28 - 0.1
12 - 0.1
32 - 0.1 (x8)
32 - 0.15
14 - 0.1
24 - 0.1
22 - 0.1
20 - 0.1
18 - 0.1
11 - 0.2

Midvalve:
12 - 0.15
20 - 0.1 (x4)
11 - 0.2
15 - 0.15
16 - 0.15
16 - 0.1
18 - 0.15
18 - 0.1

Reb:
12 - 0.15
20 - 0.1 (x3)
17 - 0.1
14 - 0.15
11 - 0.2

The normal push down test in the garage showed much improved initial plushness. I will start today with 20 clicks out for compression and rebound and 2 turns in for the PFP (per Marzocchi manual). Because of the bleed added I will start closing the comp clickers if it feels too soft and then try the PFP. I have to repeat that my previous much stiffer valving was not bad, at least for my level, for a mixture of technical trails, including sand whoops... I would say it was a very good hare scrambles setting (or, dry and fast enduro...) Probably it was helping that I had less oil in the outer chambers (but maybe not because I was experiencing blow throughs...). Very curious to see how it goes today... Hopefully I did not screw up the fork 2 days before a race. I definitely do not have the energy to revalve again tonight..

Leon

[GMP]

Leon,

Wow you changed a lot, back to stock essentially. It will certainly be compliant on the small stuff. Still, I acheived this on the GasGas without bleed on any ckt. The mid bleed in combo with a tighter float is interesting. Only thing I really don't like is the rebound bleed, especially with .48s. On this fork, the cold garage bounce test is not worth much.

[Leon_RR250]

Hi!

I am super excited from what I experienced some time ago in the dark.... Didn't touch a thing for 2 hrs, everything was just fine and comfortable in a good way. Yes I bottomed it hearing the spikes scratching the front fender in deep, slow, tightly spaced together whoops but it was completely under control (and in balance with the shock) and I didn't bother really... The sharp rocks and stones today they were just absent and at high speed, sometimes, the bike was inspiring confidence... no drama! Generally the turning in was also better. Overall a very balanced front to back package and the thing I was afraid of, packing during braking because of the weight of the 4T, never happened, probably because of the relatively light rebound stack(?). It has been sooooo long time to just enjoy a practice without scrapping my head for "what if this, what if that". I think the tighter float (and the thinner base shims) helped a lot not to get a mushy feel...

I will drive for sometime tomorrow before dark comes to keep the hands open for the race on Saturday morning and get to know a bit better my NEW bike...

I will come back with more feedback soon!

Leon

[dirtbird]

Leon, just an advice that works for me.

First try to find your preferred PFP setting and then work the clickers.

[Leon_RR250]

Hi!

On Friday with daylight I had a half an hour test on the same whoops (with a bit higher speeds) as on Thursday and the fork was really ok. On the race on Saturday I had to quit after the 2nd test because I was using the normal boots and not the special ones with the easily sliding sole we normally use in winter with snow and ice ruts (and helping "feet" ruts on the sides). These kind of ruts were plenty in several places since there was still more snow in the area than in our local trails. Big mistake by me but at least I am safe with only a small black spot on my hand and a badly bended speedometer base from a tree contact. It could be much worse so I am happy I can continue normally the practices with my new bike. There were several fast parts in the tests and some steep downhills and the fork was good. Until now I have only felt that I could tighten more the rebound clickers. The sound of spikes scratching the front fender was something else since there were no signs on the fender and the fork still has 3-4 cm unused at the end of the stroke.

The net is the best and worse place.... Based on the other discussion on thumpertalk with the guy complaining a lot about the stock valving I never thought and never wanted to try the 2T settings. There must have been something really strange in the fork or he was super fast at pro level (and I don't think so since he completely converted the mid to a check plate (only 4x20.1) with lots of float.... and the disaster was partly controlled with a normal single stage stack on the base.

Leon

[GMP]

Your right, these forums are full of all kinds, most just like to hear themselves BS. To me its just a bad habit, but I like threads like this where something good comes out of it.

Eventually when things warm up you may want to get rid of the rebound bleed. I always found the clicker wanted to be withen 5 clicks out with the bleed shim in there. Mid bleed will affect this a bit too. I'm racing Sunday with slightly stiffer base stack, stock bleed, and bleed removed from the rebound and mid. New anodizing and all new bushings/seals. Shock was stiffened slightly as well. Its going to be cold, course that is wet sandy dirt now will be frozen. So much snow where I live testing is impossible so I'll find out how it works after the flag drops.

[Leon_RR250]

Good luck for your race on Sunday! Yes, this thread has been good and I am really thankful for your help and these last tips for the rebound clickers and stack. And I believe that I would much improve still the previous stacks with your help if I didn't have the confirmation that the stacks are the same as for the 2Ts. I will try very soon few clicks in for the rebound and because I want to keep the comfort through the stones, I will take small steps for tightening the rebound. I will turn the clickers until it packs and becomes uncomfortable for the arms and then back off a bit.

Leon