Marzocchi fork problem, help!
dr crash
Posts: 53
Hi,
I've got a pair of marzocchi bomber mx comp 03 air forks which are playing up.
There is a severe topout after any kind of compression, even at a low psi, i think the problem is either the rebound is too low and needs adjusting, or i need to change the oil for a higher viscosity. Does that sound right?
Any ideas or suggestions would be helpful.
I've got a pair of marzocchi bomber mx comp 03 air forks which are playing up.
There is a severe topout after any kind of compression, even at a low psi, i think the problem is either the rebound is too low and needs adjusting, or i need to change the oil for a higher viscosity. Does that sound right?
Any ideas or suggestions would be helpful.
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Comments
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Have you had them apart recently??. Mine did this when the small 3/4 plastic washer broke on one of the legs, even if you put treacle thick oil in it doesn't solve it, mine were okay onl 35wt oilbut not how they were, usable but not quite bob on!!!Timmo.
After all, I am Cornish!
http://cornwallmtb.kk5.org/
Cotic Soul, The bike of Legends!
Yes, I Am a bike tart!
http://www.bikeradar.com/forums/viewtop ... 1#162974810 -
i've only just got hold of them so i don't know if the previous owner did or not which isn't too helpful!
So i'm probably going to need a new washer then do you reckon? Also i've no experience of taking forks apart, do you know of a good manual online?
cheers mate!0 -
dr crash wrote:i've only just got hold of them so i don't know if the previous owner did or not which isn't too helpful!
So i'm probably going to need a new washer then do you reckon? Also i've no experience of taking forks apart, do you know of a good manual online?
cheers mate!
Do they still have oil in them, if so how old is it, is it the right viscosity and are the oil levels correct?
From what I can remember there should be either 125 or 135ml in each leg of 7.5 wt oil, check Windwave or Marzocchi for oil volumes.0 -
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If you're going to have them apart then depending on the travel you have, they have a plastic sleeve bushing on the leg, if 105mm then is a 15mm spacer you can remove to bump them to 120mm!Timmo.
After all, I am Cornish!
http://cornwallmtb.kk5.org/
Cotic Soul, The bike of Legends! Yes, I Am a bike tart!
http://www.bikeradar.com/forums/viewtop ... 1#162974810 -
right, i'm not sure how old the oil is, the levels, and viscosity as i the previous owner hadn't got to sorting the forks out yet.
I suppose the only way to find out is to get them apart then! Will report back later if i have any issues!
Thanks0 -
Finally got a chance to get them apart today, the oil levels were around the 125ml mark as dirty dog thought they would be, however looking at windwave for the mx comp air 2003 it's only supposed to be 45ml!
tried it at 45ml but just made the topout worse as i expected, popped all the oil back in and it seems to have helped quite a bit.
However the oil did seem quite murky and discoloured so will try some new oil.
Any other thoughts as to what else would help?
Thanks0 -
dr crash wrote:Finally got a chance to get them apart today, the oil levels were around the 125ml mark as dirty dog thought they would be, however looking at windwave for the mx comp air 2003 it's only supposed to be 45ml!
tried it at 45ml but just made the topout worse as i expected, popped all the oil back in and it seems to have helped quite a bit.
However the oil did seem quite murky and discoloured so will try some new oil.
Any other thoughts as to what else would help?
Thanks
Are you sure it says 45ml and not 45mm?
You have been looking at the oil height tables and not the the oil volume tables.
Check again as there two ways of measuring the correct amount of oil in Marzocchi forks, the first is by volume and the second is by height, they provide both figures.
If my memory serves me right the recommended oil levels in my 04 comps was between 45 and 55mm below the top of the leg with both legs fully compressed or between 125ml and 135ml in each leg (depends on rider weight) .
You can fine tune the oil heights, the more oil you add the quicker they will ramp up.
There are instructions somewhere on the Marzocchi site on how to measure oil levels.
But try here first. 0 -
That's most likely the reason, there were no units of measurement or key on windwave, just a load of numbers so it's not too hard to get confused when you don't know what you're doing!
Is it better to change the oil levels or viscosity of the oil in order to change the rebound?0 -
i changed the viscosity of mine to get them back from chronic top out after i broke the plastic 3/4 washer sleve,
there may be a rebound adjuster on on eof the legs, requires a long allen key to get at!! (i used an allen socket attatchment and extension bars!) but if your getting bad top out then i doubt it will affect them too much??Timmo.
After all, I am Cornish!
http://cornwallmtb.kk5.org/
Cotic Soul, The bike of Legends! Yes, I Am a bike tart!
http://www.bikeradar.com/forums/viewtop ... 1#162974810 -
dr crash wrote:That's most likely the reason, there were no units of measurement or key on windwave, just a load of numbers so it's not too hard to get confused when you don't know what you're doing!
Is it better to change the oil levels or viscosity of the oil in order to change the rebound?
I know mate, which is why I'm trying to help.
The problem is if you change the viscosity you'll also change the compression damping.
They do have a rebound adjuster but its located down the inside bottom of the right hand leg and and it's awkward to find even with the a foot long allen key they provide, from experience it has little effect, but give it ago it can't hurt.
If you don't have the big allen key/rod you will only be able to get at the adjuster once the forks are apart or as allthegearnoidea says an allen key on a stick or something similar.
Have a look at the manual for instructions on rebound location and adjustment.0
