How do I adjust my Marzocchi Bomber Z4
I'm new to the world of mountain bikes and have a quesion on the fork on my 99 Kona Caldera. I just picked this bike up on the used market and it has the Marzocchi Bomber Z4 Fork installed. It feels a little soft and I would like to stiffen it up a bit. Can anyone that has one of these forks tell me how to make the adjustments.
If it is a coil fork, you'll need a heavier spring. If it is air, pump it up. Definatelly do an oil change, too. Puttin in heavier oil might make it feel firmer too. Stock is 7wt.
Originally Posted by FoleyF
"The difference between stupidity and genius is that genius has its limits."
-- Einstein, Albert
What size is that frame and where did you get it? Is it this bike?
(select "caldera" from menu on the left after the page loads)
I've been looking for one of those in 18" frame for a while now.
If it is that one, it's an oil/coil fork. You can remove the top caps from each leg and add a little bit of oil to each leg. That will stiffen it up a bit. Just don't add too much!
Last edited by Que?; 04-21-2006 at 08:17 AM.
Originally Posted by FoleyF
you can download the manual from the marzocchi site
Check out the oil height table in the technical area as well.
If you weight more than about 160lbs, I'd recommend that you get a firmer spring.
You can get 'em from marzocchi (either direct or through your LBS), but Cambriabike has had some on clearance for around $30. If you get marzocchi springs, get one firmer than what the stated weight is, if cambria still has the MRP speedsprings, get those for the stated weight range.
As I recall, you can only adjust preload on those (pry off the rubber topcap and there's a 4 or 5mm hex screw to increase preload), and damping by changing the weight of the oil. Increase preload clockwise, and do it on both sides about equally. Increasing preload will make it firmer.
As already stated, you should do an oil change on the fork soon, unless you know it's been maintained regularly. If you can do basic DIY mechanical work, the marzocchi forks are easy to work on.
If you're under 200lbs, stick with the stock 7.5 wt oil.
There's good instructions w/ pics for oil change (plus seal install) at enduroforkseals.com for a bomber that's similar (I think he's got an air fork on there... x-fly, but it's close enough. He also has the manual for your fork on his site.)
Stock oil is Golden Spectro 7.5wt (125/150?), but just about any fork fluid from a local motorcycle shop (much cheaper to buy at a motorcycle shop than the bike shop) will work fine (belray, silkolene, maxima, etc).
If you find that you're bottoming out the fork easily, add oil to the top of the oil height range (fork compressed & springs out), so closer to 40mm than 45mm, if that's the range on the chart (that's what it is on my Z2).
the caldera's are nice bikes, enjoy!
Last edited by logbiter; 04-21-2006 at 08:13 AM.