Hopefully a quick question about setting up my 2006 Marzocchi MX comp (85mm).

I'm fairly light, 65kg to be precise and I'm having trouble setting up my fork properly.  At the minute I'm using half to three fifths of it's travel (measured using a plastie around a fork leg on a ride).  That's not a lot of travel seeing as the fork only has 85mm to start with.

I've looked on the marzocchi website and for my weight these are the correct settings:

air pressure=36psi

oil level=135mm

The air pressure I'm running at 28psi and I'm still getting hardly any travel, when set to 36psi I get even less travel.  The problem at 28psi is I have 210mm of sag (too much I know).

Is the oil level too high or are the springs too stiff for my weight (or both)? If it's the oil level how do I check the level? I can open up the fork no probs (I have to it is internal rebound adjust), so I can get to the oil, but as I said before where do you measure from/to? If I need to replace the springs, how do I go about it? I can't even find out where to get springs from.

Quick answer

Take all air out of both legs check that it travels full extent.

Take all the rebound adjust off turning adjuster fully clockwise and check that its not a shock absorber problem

The oil is in cc's 135 cc per leg, buy a cooks measuring jug. empty em out and refill.

Quick question 

how do yo get 210mm sag out of 85mm forks ?

For somebody so light you ought to look at an air fork.

Although we put lighter coils into my sons' Marzocchi DJ's and that certainly helped - he weighs 30kg...

Thanks for the replies.

I did mean 21mm of sag sorry about that.

I'll check the oil level like XCman said first and let you know how much is in them.

What would be the benefit of an air fork for someone my weight b r?

Ok I just measured the oil levels, the drive side stanchion (?) had 105cc's and the non-drive side stanchion had 160cc's.  So the oil levels were way off, thx Marzocchi!

I let all the air out and the fork dropped straight away, so no problems with the actual travel on the fork.

I tried the fork at 135cc's with the correct air pressure (36psi) for my weight and it was still way too stiff.  So I took it down to 100cc' (quite a lot below what Marzocchi state on their website for my weight) and tried 32psi and it was marginally better, but not by a lot; it was using about 3/4's of the forks travel.

So I can only conclude that the spring in the fork is meant for a beefcake not a lean, mean lovin' machine such as myself.  Is there anything else I can change or try before changing the spring?

How do I determine what spring I have at the minute anyway and is it easy to change a spring? Or would it be better getting an 85mm to 105mm travel kit to give me a bit more travel?

No spring, Doh!!

Maybe it is my gauge then, but it is a proper marzocchi shock pump, that until recently has only been used once a month or so.

Would it do any damage taking even more oil out?  I'm 35cc's below the recommended level now, if I took another say 10-15cc's out, would that help do you think or am I running the risk of bottoming out/ruining my fork? Would using a thicker/thinner oil do anything?

Just drop the pressure to 20psi and try that, don't keep taking oil out as the oil sloshing around is why (most) Marzocchi forks keep working well for ages.

If I run my 2004 Z1 FR SL's or 2008 AM1 SL's at the recommended pressure for my weight then I might as well be running rigid forks (same with RS forks as well) Fox seem about correct with the pressures recommended?

Golden rule of changing things is one at a time.

Try what JG says re oil and pressure. .

Fox seem about correct with the pressures recommended?

if you like running your forks rigid. I have to run @ about 60% of Foxes recommended pressures on four sets of fox forks and still only get 90% travel on a typical ride.

Forks seem to have gone a bit weird now.

I put new 7.5 weight marzocchi oil in, 135cc's (the correct amount) and I now have to put about 45 psi in to stop it bottoming out, way above the 36psi for my weight.  I give up!

Maybe it is my shock pump, is there any other way of checking the pressure (without having to buy another pump)? Could I do it at a petrol station with an air hose there?

Think I have it sorted now. I bought a new shock pump and it seems to be a lot more consistant than my last.

I've settled with 100ml of 7.5w oil and 32psi, seems to be a lot better now, quite plush.  I don't know what Marzocchi were thinking with there reccommended oil and air settings, but they were way off the mark (for me at least).

Anyway thanks for the advice guys.

The oil level should be 50mm below the top of the stanchion when fully compressed.

I check this by measuring a 50mm section of hose on a syringe and drawing out the excess.

Then set the air pressure that gives you 20-25% sag when out of the saddle with your riding kit on.

The tricky bit is adjusting the rebound to your spring rate as you have to let all the air out and adjust it and then set sag again and test rebound etc. etc. to get a nice progressive spring rate and correct damping.

A low oil level will produce a very linear midstroke with a big ramp up in the end stroke, and unpredictable damping in the worst case, from cavitated oil entering the pumping rod assembly.

Cheers for the reply.

Where did you get '50mm below the top of the stanchion when fully compressed' from, trial and error or is that pretty standard?

That's the Marzocchi standard procedure for that kind of fork. It's in the manual and tech docs.