Swapping forks...please be nice!

Iain C

I've passed on my old MTB to my girlfriend since I've bought my Trek Fuel, but she understandably wants suss forks on it (it's a Ventura Monteray, it's not too bad and she's quite happy to hack round on it whilst she decides if she wants something more upmarket).

I've been offered a set of Marzocchi Bomber forks off my mate's trashed Kona Cinder Cone (head welds cracking) for £40 and I want to do the swap. Both bikes are aheadset equipped, but I've only ever played with screw threaded forks. I know you guys want tech details if poss, I think the forks are about 8 years old, they are metallic blue, have the word "Lite" at the top, the bridge thingy is a separate piece of ally held to each leg by bolts, and they have both disc and V brake mounts...I hope that's enough detail!

Three questions for you...

One, how do I swap them over (I'm pretty mechanically minded but I just wanted to know if there are any special tools required or anything I should be wary of)

Two, before I do it should I be checking anything on the Marzocchis to know they are OK before I do it? Particulalry with regards to seal integrity, ball bearings falling out everywhere etc...

Three, if they are off the bike, should I service them and is it possible for an average DIY mechanic to do? I was reading in WMB about servicing the Fox Float rear shock on my own bike yet I'd always been led to beleive that shock servicing is an LBS job?

Thanks in advance!

nicklouse

ok have a read of parktools on the headset area as it gives all the info you need.

Remember to swap the crown race off the old fork an fit it to the new fork.

Boffington

is the frame your fitting the fork to suspension corected if not it could make for some wacky handeling (think chopper moterbike)

Iain C

Thanks guys, really useful, Park website covers most stuff!

Geometry wise presumably it will raise the front end, in effect making the head angle shallower and slowing the steering down? Is it likely to be bad enough to make it a non-starter, or shall I just put them on and see what it's like to ride?

nicklouse

Iain C wrote:

Thanks guys, really useful, Park website covers most stuff!

Geometry wise presumably it will raise the front end, in effect making the head angle shallower and slowing the steering down? Is it likely to be bad enough to make it a non-starter, or shall I just put them on and see what it's like to ride?

might, might not. not enough info as the old fork and new fork are not identified.

the Marz could be one on many. with travel from 60mm to 130mm.........

measure the axle to crown heights of both forks. 25mm will change the head angle by 1 degree.

Iain C

Thanks for the continuing help and the Park linky.

Presumably to check that measurement, I'll need to put the forks on and get girlie to sit on bike and then measure as there will be some sag when she gets on it? In your experience what would you say would be an acceptable level of variation for someone who at the end of the day is just a beginner looking for a bit more comfort when riding?

In addition (and forgive me here, just thinking aloud as a newbie) the current stem on the bike is very, very long (stupidly long for her as she's only ickle), and the Marz forks come with a much shorter one. If, in effect as the front of the bike goes up due to the new forks, and makes the steering a bit slower, will the new shorter stem help counter this and sharpen it up a bit?

nicklouse

Nope just measure off the bike it is just the static length that is of interest at the moment.

also do check that the steerer tubes are the same size. 1 1/8th inch?

Iain C

OK steerer tubes look the same, so hopefully no probs there.

The only markings I can find on the Marz forks are Bomber M3 Light. It was a bit tricky to work out the travel as they are not part of a complete bike any more, but suffice to say that from the top of the moving part of the fork to the ally crown is only 80mm, so presumably the travel is a bit under that anyway.

Axle to crown height is 435 on the Marz forks, 400 on the old forks, so presumably we're only talking just over a degree of change, and I reckon she'll live with that.

However trying to compress them has highlighted that they are a quite leaky and could certianly do with seals and a service, and I wonder if it's worth it. Are the seals a DIY job?

Iain C

OK here's some pictures of the forks...if anyone can tell me what they are presumably I can check on the Marzocchi site and get the manual and the required spares...

Sadly the Cinder Cone frame is history, slight cracking around the head...







Thanks!!

nicklouse

down load a 2000 year manual all the info is there.

Iain C

Superb, thanks for your help, much appreciated.

nicklouse

might be the 2001 year manual. but the ones of that time had a bit more info in. In fact