2010 Marzocchi 888 Evo tuning thread

[Hacktastic]

As I suggested in the other thread, someone should start a separate thread dedicated just to tuning this fork. So here it is. This applies to springrates, shimstacks, oil viscosities/heights, and other voodoo to make a fork more better. In similar fashion to the Sunday thread, I'll update this original post with pertinent information, links, etc as it becomes available. It will be easy for everyone including new owners, and it will be good reference for me too. Let's keep the discussion strictly about tuning so there's not a ton of stuff to wade through.

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Here's the basic stock stuff:

Springrate/numerical rate/rider weight range
SOFT / 4.4 N/mm / --
STOCK / 5.5 N/mm / <200# (30% sag, 67kg/147# rider)
FIRM / 6.5 N/mm / --
EXTRA FIRM / 7.7 N/mm / --
(I do know that there are 4 available)

Oil
Stock oil should still be Spectro 7.5 (26.10 cSt @ 40C)
300cc/mL in the damper side for the regular Evo
320cc/mL in the damper side for the Evo Ti to compensate for the tapered stanchion volume
80cc/mL in the spring side.

Valving

Base Valve stock setting(unconfirmed):
All 8mm ID x .15mm thickness
20mm
19mm
18mm
17mm
16mm

Total stack height affects compression needle range

[EVRAC]

Great thread.

I had not heard about multiple spring weights. Where did you see this?

Are there really no dealer service instructions or anything published for this fork?
I doubt the oil heights will be the same as the internals are quite different.

Found a little review here:

http://forums.mtbr.com/showthread.php?t=567359

[Hacktastic]

The internals are different, but they are still open cartridge in the same chassis. I can't imagine the total volume of the damper changed noticeably, or the depth of that volume adjust piston. Will find out for sure though.

Marzocchi typically has rebuild instructions available to dealers online. I'll try to get a copy and see what it specs, if it's available yet.

I got the 4 spring weights info from their sales rep. They also say that the stock spring should be good for someone up to 200#. I gotta admit the range of spring preload adjustment on it is HUGE, but I'd still rather go with a stiffer spring and less preload if I had the option. Nice to have there as a band-aid fix if you should ever need it.

The initial stroke on this fork is just insane though...it just makes little junk disappear.

I noticed another thing when I had the lower crown off. The damper sides on both the forks we installed today want to suck down a little bit from full extension - inch and a half about. It looks like they closed off the damper side of the fork just short of being topped out. That could serve two purposes: one being a top out "cushion" of negative air pressure anticipating that riders will be running spring preload, and to make the initial stroke smoother. When bolted up in the crowns, it is not enough downforce to make the spring side compress at all.

[gemini2k]

This weekend, on your birthday no less, when youre not looking, I'm going to open your damper top cap, and drop a duece in there. That'll teach you to be a parts whore.

[Hacktastic]

Well this thread got fouled in no time. I suppose that's what I get for my lone legitimate posting on here. Only fair I guess...

[JohnnyC]

I run the stock spring, there are 2 heavier ones and one softer

stock -5.5N/mm- 30% sag- 67kg

Stock oil is 7.5wt as always, 300ml in the damper, 80ml in the spring side

Standard valving is from memory-

20mm x1
19mm x1
18mm x1
17mm x1
16mm x1

All 0.2mm thick, 8mm ID

The 2 heavier springs are 6.5 and 7.7 N/mm, the softer is 4.4 n/mm


So far the stock settings all feel pretty good for me but the rear end of my bike is a little stiff at the mo so if I change that it may change the balance of the bike a little bit.

I hope everyone can handle my metric measurements

[leprechaun]

If you're sure the shims are 0.2mm thick then there is the opportunity to put thinner shims in, and put a larger stack, and/or a 2 stage stack easily.

Can you verify?

[Hacktastic]

Info up top updated - thanks JohnnyC!

Got a ride in on the fork today, as did my heavier friend with the preload cranked down. I'm 170# and he's 230#. Honestly, it feels DAMN good out of the box. Crazy smooth, opens up nicely at speed, and ZERO bushing bind if the bike is leaned over. Really odd feeling on flat corners where it still articulates perfect.

For anyone wondering, the bushings are tight as hell on these. I'm hoping they stay that way.

I ended up 6 clicks in on preload, 4 clicks in on compression, 0 in on progression, and was playing with the rebound a whole lot and will continue to do so. No point in recording it just yet.

The guy who is 230# with the stock spring found a good setup with the preload full in, progression adjustment 6 clicks out from full-in, compression 6 clicks in, and rebound 13 clicks in.

[dilzy]

Is it easy to remove the rebound piston on these things?

Oh and do they come with more than one spring, or can you specify the spring when ordering?

[Hacktastic]

Haven't heard anything about it coming with other springs. You could probably ask for another spring if you were ordering from Zoke or somewhere that had springs in stock.

I would imagine the rebound piston/rod would come out the bottom of the cartridge once the whole top cap/air piston assembly was taken down.

[Hacktastic]

I'd also like to find out if the total stack height of the shimstack is critical to the function of the adjuster needle.

[dilzy]

If the LS needle has enough extra thread, it will still bottom on the piston seat. Be nice if there was enough extra adjustment room for 2mm of stack.

[JohnnyC]

If you're sure the shims are 0.2mm thick then there is the opportunity to put thinner shims in, and put a larger stack, and/or a 2 stage stack easily.

Can you verify?

Yeah it doesn't seem to cause any problems if you go a bit thicker, the needle will still bottom on the piston bolt but I'm not sure how far it can go. Going to a thinner stack is no problem, just add some 11mm spacer shims on the end

[Hacktastic]

So the total shimstack height DOES affect the compression adjusters range, correct?

At some point that total stack height of shims/washers between the valve body, piston, and bolt in mm and total shims would be useful.

[JohnnyC]

So the total shimstack height DOES affect the compression adjusters range, correct?

At some point that total stack height of shims/washers between the valve body, piston, and bolt in mm and total shims would be useful.

Yeah although I don't think it would have any practical effect on adjustment range, if you are adding shims to the stack but running the adjuster wide open then you didn't need the extra shims. As long as you maintain the same minimum thickness if you are making a "softer" shim stack then it will be fine.

I'll have my own fork apart in the next few weeks, I'll remember to take more measurements then.