[Paul B]

First off, yes, I did an extensive forum search. Found lots and lots of conflicting information, so I thought I'd start a new query from scratch.

Me: 220# fully loaded with a day's worth of crap

The bike: 2004 Intense 5.5 set up for all-mountain, aggressive riding

The fork: 2004 Z1 FR SL

The problem: Setting up the fork. Of course. Marzocchi's recommended pressures give me an extremely non-compliant, stiff, nasty-acting fork. I believe they recommend for someone 100kg (me) to run 45+/110-. Tried it. Yuck.

So then I went with setting up the fork like I would a coil fork, by setting the sag first. I load up, put a zip tie on the fork, hop on. Naturally there's only about 2mm of sag at the 45/110 setting. So I keep backing down the pressure until I get to about, um, 25 psi. Then I have about 1/2", which still seems "high" compared to my coil forks (Z1 Dropoff and a Z150, each of which run about 1" of sag or more). But now the brake dive wants to kill me ON A PAVED STREET. There's just not nearly enough positive pressure in the fork to hold me up. Or maybe there's too much negative. So I back down the negative, to about 80ish. Feels...okay. But when I ride on it the fork feels unpredictable, dive-y, mushy, generally undersprung. Scary.

I'm looking for that sweet spot where the fork resists braking/pedaling, is plush on small-to-midsize bumps, doesn't bottom on big hits, and still gives me my full travel in the course of a typical technical ride.

Do I empty all the chambers and start first setting sag with positive pressure and NOTHING in the negative chamber? That doesn't seem right. The negative chamber will increase my sag, won't it?

Do I set, say, HALF my target static sag with the positive pressures and make up the difference with negative pressure?

And what's a good target for sag on a 130mm air fork, anyway? I feel like nothing is the same with air vs. coil, although they're just two different spring media.

Or...do I ignore all considerations of "sag" and go strictly by M's pressure chart? I have no idea what the Italians were smoking/drinking/eating/sniffing when they came up with that chart but it has no bearing on reality.

p.

 

[Mr.Whitney]

Really the manual should just be a reference to get you started. There is no way a manual can know the type of riding you do or your personal preferences. I also ride aggressive, with alot of jumping, drops, and fast on really rocky technical terrain. I weigh 175 and run about 36 in positive and 85 in the negative. Until the fork is broken in it will be hard to find the right settings. Also, I found that when the ECC is in the 1 position the rebound is too fast and the fork will top out hard. As for sag I didn't really worry about that; once you find the right pressure settings that should take care of itself. I took my fork pump with me to the trail and messed with different pressures until I found what I liked. It will a little fiddling with but it will be worth it in the end.

 

[Paul B]

Okay, so one vote for "go with feel." Whitney, how much static sag are you running on your fork as it's currently set up?

p.

 

[tscheezy]

Aaah yes, the Z1 SL. I have had mine a year and am just now narrowing in on the right oil height and positive and negative pressures.

I weigh 195# with my crap. I do about 36-38psi positive on each side and about 160psi negative, keep the ECC knob at the middle setting at minimum(for good rebound control), and run about 95ml oil in the right leg in 15 wt. What this all does is: slow down the rebound so you don't get a top-out WHACK!, balances the positive and negative so that I can get some sag at least (the fork will never sag much if you run enough positive pressure to preserve your life offroad: don't expect more than 10-15mm), and allows me to get pretty much all the travel without bottoming except on the biggest fockked-up cases.

Zoke's suggested values are bogus. Use their suggested positive pressures and then keep adding negative until you get a fork which does not slam home at extension/top-out. You will have to increase the oil weight (try 10 and then 15) and run a slower ECC setting (the middle of the 5) to achieve this. The fork will always seem tall and will not sag like a normal fork. To get more sag and not suffer catastrophic bottoming I guess you could add about 180psi negative and lower the positive and raise the oil height and all that jazz, but that is getting pretty out-there.

It is a very very hard fork to dial in. Once set though, it is pretty sweet. Just a PITA to get to that point. It also requires a bike which is accommodative to that resultantly long A-C height. I'm not sure your 5.5 is such a bike. It is a fork tuner's fork. It is not plug and play like Foxes, Manitous, or most other Zokes. If you are willing to put in the time and effort though, it will reward you in spades.

 

[Mr.Whitney]

Okay, so one vote for "go with feel." Whitney, how much static sag are you running on your fork as it's currently set up?

p.

I am not really sure. No more than inch, I think, I can't be for sure. When I first got the fork I knew, from previous experience with Marzocchi forks, that it would not feel right until I had broken it in; so, I used the suggestion from people on here, and found that I didn't like those settings. Then I took what the manual said and adjusted it to my liking. I didn't raise or lower the oil, hell I have never even opened up a fork or tried to adjust the oil. That's just extra work that I would rather pay the guys at the bike shop to do.

 

[Paul B]

Cool, excellent feedback tscheezy! One vote for "set the sag but don't treat it like a coil fork".

The variations in pressures and settings for this fork are outrageous! I didn't think the negative chamber could even TAKE 160psi -- actually I think the manual specs it only to 150. And of course my Wrench Force shock pump holds about 50 psi in the hose alone, so I have to way overpump, disengage, re-engage it to test the pressure in the chamber, re-re-overpump...bleagh.

I'd be interested in putting together a table that cross-referenced rider weights with their pressure settings. Might come up with some interesting findings -- or it might be that everyone prefers a fork that feels different.

The oil thing is scaring me, but only because I haven't cracked it open yet. Everyone's saying it's an easy fork to mess with. True story?

Okay, so I think I'm gonna go with this: Empty the chambers, crank up the positive until I get about 10mm of sag, and then crank up the negative until it stops diving on me. Will increasing the negative actually increase the sag? I haven't found that to be true yet in the pressure ranges I've been experimenting with (current settings are 38/110).

I've been running the rebound on setting 2, which so far has cured the topout clunk. The first time I heard that I thought I'd somehow blown the shock. In the air. But I'm gonna give setting 3 a swing as well.

Bike probably has about 100-150 miles on it so far. Sounds like the seals may still be getting comfortable.

p.

 

[006_007]

Okay guys, I am liking what I hear about this fork. I have been planning an upgrade for my 02 enduro, and I think this is what I am going to go with. Jenson has them on sale for $399, I just need to get more feedback/reviews. The MTBR reviews are all from bigger guys (I am a buck seventy five) so was initially worried that I could not get it to work.

The fork I currently have is a manitou black elite. In your opinions would this be a wise upgrade

Apologies for the semi thread hi-jacking.

TJ

 

[tscheezy]

" Okay, so I think I'm gonna go with this: Empty the chambers, crank up the positive until I get about 10mm of sag, and then crank up the negative until it stops diving on me. Will increasing the negative actually increase the sag? I haven't found that to be true yet in the pressure ranges I've been experimenting with (current settings are 38/110)."

No, no. You will not get any sag just playing with positive. Go for about 38psi positive and 150 negative and then check. Drop the positive at most 2-3psi and go up in negative until the fork sags just a touch. It will never sag much. New SLs are also very notchy at topout for a month or two. This smooths out and goes away with time and a good oil change. And get a better shock pump. Note: if you pump the fork up and then unscrew the adapter from the fork, you do NOT lose any air from the fork. The rush of air is coming out of the pump! The reading on the gauge when you started removing the pump is the correct reading. Reattaching the pump causes the gauge to then read lower since it steals air from the fork to repressurize the pump.

Oil change:
Take the fork all the way off the bike.

Put the ECC side in the lowest ECC setting (not locked down). Remove both top caps. Don't lose any pieces.

Take the pump adapter and slowly screw it into each of the chamber valves to release the air in the fork. Start with the negative and then both positives.

Find a 6-sided, 22mm socket (this fits the 03 SL anyway). Grind the face down so that the wrench flats extend ALL the way down to the opening. The wrench flats on the fork's top caps are very shallow so you want a GOOD engagement.

Loosen ECC side's the top cap until the threads are backed all the way out and you can compress the fork a little. It generally helps now to attach the pump adapter back onto the positive chamber valve on the other leg to let that chamber evacuate as you compress the fork.

Tip the fork over and let the oil run into a large cup. Pump the rod/top cap a little, and drain some more. Do this a lot, turning the fork upright, pump, flip, dump, pump, dump, back and forth etc until you hear/feel air in the cartridge and no more oil comes out.

Carefully, accurately, measure out 95ml (cc's) of 10 wt "cartridge fork" oil (Maxima, Bel-Ray, whatever) and pour it into the leg.

Screw the top cap back on and inflate the fork. I would inflate both positive chambers first to about 38psi, then pump the neg up to about 150psi and ride around the block playing with the ECC to gauge the rebound activity and general feel. Add negative as needed. The negative chamber only has an effect near topout since it is such a tiny volume. Just use it to set the behavior near full extension.

006_007, if we have not scared you away yet, then there is no helping you. If you really like to tinker, get the SL. If you don't want to spend a lot of time futzing, get something else.

 

[Paul B]

Holy cow, real advice!

This need to go into a FAQ somewhere. Best advice I've yet read about this shock. Why on Earth would M hide the oil change procedure from the public? This is really something that should be in the tech manual.

I think I'm gonna try the oil change by the end of October. That'll give me a couple months on the fork and it should be plenty broken in by then.

I remember reading somewhere that the ECC leg should have like 85-95cc of oil while the other leg should have just 50. True?

Ended up at 35/150, which feels pretty good on the road. Got it to about 20mm of sag and a pretty plush feel on front yard rocks and steps. Curious to see how it plays out on actual dirt.

Better shock pump = one that isn't rated to 300psi, I assume? What's your recommendation?

Thanks again for the heads-up!

p.

 

[tscheezy]

The oil change should happen early and often during break in. It will speed up the process of making the fork feel good. 95-95ml right leg, 50ml left leg. The left leg oil us just to lube, it does not affect bottoming control. Play with the right leg oil for that. Higher oil lets you run less positive pressure and thus lets you achieve more sag without bottoming. It takes time to figure out what works best.

I have an OK pump I got a supergo a while back. It is just the typical rebadged thing:

This one supposedly has a head valve which reduces air loss when unscrewing (not an issue with the Zoke adapter)

 

[staz]

negative psi max?

Aaah yes, the Z1 SL. I have had mine a year and am just now narrowing in on the right oil height and positive and negative pressures.

I weigh 195# with my crap. I do about 36-38psi positive on each side and about 160psi negative, keep the ECC knob at the middle setting at minimum(for good rebound control), and run about 95ml oil in the right leg in 15 wt. What this all does is: slow down the rebound so you don't get a top-out WHACK!, balances the positive and negative so that I can get some sag at least (the fork will never sag much if you run enough positive pressure to preserve your life offroad: don't expect more than 10-15mm), and allows me to get pretty much all the travel without bottoming except on the biggest fockked-up cases.

Zoke's suggested values are bogus. Use their suggested positive pressures and then keep adding negative until you get a fork which does not slam home at extension/top-out. You will have to increase the oil weight (try 10 and then 15) and run a slower ECC setting (the middle of the 5) to achieve this. The fork will always seem tall and will not sag like a normal fork. To get more sag and not suffer catastrophic bottoming I guess you could add about 180psi negative and lower the positive and raise the oil height and all that jazz, but that is getting pretty out-there.

It is a very very hard fork to dial in. Once set though, it is pretty sweet. Just a PITA to get to that point. It also requires a bike which is accommodative to that resultantly long A-C height. I'm not sure your 5.5 is such a bike. It is a fork tuner's fork. It is not plug and play like Foxes, Manitous, or most other Zokes. If you are willing to put in the time and effort though, it will reward you in spades.

great tips man.
whats the highest psi you can run in the negative. i'm at 175 psi. rider weight is 225. i havent changed the oild yet, but it's due. seen you mentioned 180 psi.

 

[mzungo]

Warning read this

great tips man.
whats the highest psi you can run in the negative. i'm at 175 psi. rider weight is 225. i havent changed the oild yet, but it's due. seen you mentioned 180 psi.

2004 and 2005 shocks have widley direrent pressure settings ....04 must not be pumped past 150psi...

Alec

 

[pmorrise]

just a thank you.....

Hi Guys, just wanted to say thanks to one and all for this post, I've fitted a z150 sl to my bike a few week's ago and I was seriously thinking about selling it due to the crap feeling of the rebound and the relly bad topout, but of course I've been following the manual (big mistake!) so now I've changed the oil for 10w and run 35 psi + and 120 - pressure and on the third click on the ecc, that horrible top out clunk has been sorted out and the fork seems pretty dialled for my kind of riding (hardcore XC, not so much freeride)

Thanks to you all here I got it working ! cheers for the tips guys.

Patrick

Ireland.