Suspension fork travel

[Andrew G]

One for the proper MTBers who know their onions, and forks.

I'm keeping an eye out for some second hand Bombers (a Grahame and Dombo recommendation) on ebay as there seem to be plenty about with a lot going cheaply. My question concerns travel as there seem to be a number of Bomber variants. From memory I've seen 100mm, 120mm, 150mm, and then huge travel for nutter bikes.

On my Marin Palisades Trail circa 1994/5ish what sort of travel should/could I use? I want a reasonable amount as the standard forks have bottomed out on at least one drop-off in to a compression, but they I have no idea what they have - but don't think it's that much. Instinct tells me 150s would be too much, OTT, and create to much rake, would 120s do the same? Should I go 100s and nothing else?

The bike has an ahead so is the fork fitment similar to a road one (1 1/8th"), apart from setting up the suspension itself?

So long as they've been serviced etc and just have the normal use scratches should they be okay?

Any info much appreciated.

The fool who acts like a big kid as soon as he sits on a MTB .

[Dombo]

Circa 1994 you should be ok up to about a max 80mm of travel. My old Bombers, Z2 Atom Bomb forks had 63mm on a 1999 bike. That's about the minimum you can get. After 80mm on a 1994 bike the geometry of the bike will be thrown off and it will feel wrong. The main thing to check for is the condition of the stanchions, the shiny internal legs, that they are not scored or damaged. External scratches on the fork legs are ok. The internals can be overhauled/replaced by a competent diy-er or Nirvana Cycles in Westcott will get them good as new for £50.
Generally speaking they should not bottom out, as you absorb a lot of movement just flexing your arms.
The great thing with Bombers is that they are very well made and almost infinitely serviceable.

[Elliot M]

While 80mm is probably right, the actual length of the fork (axle to crown) is more important than the travel here, and different makes/models will vary even if travel is the same. I think Marzocchi are longer than RockShox, for example. You should be able to look this up and compare with what you have at the moment. Remember when riding, the fork will be about 25% into its travel.

Dombo is right, even a 100mm fork on a bike not designed for it will feel wrong. I did this years ago and it made getting up short steep climbs surprisingly difficult!

Some Marzocchis could be (relatively) easily switched from 100mm to 80mm by switching spacers around. I'm pretty sure Grahame runs 80mm forks on some of his vintage MTBs so I would definitely tap him for advice.

Do double check that your steerer is 1" 1/8th! Oh and make sure that any 2nd forks have enough steerer to fit - but given like me you aren't the tallest this is unlikely to be a problem.

I do have a pair of 2000-ish Marzocchi MXC Airs lying around. 100mm, 1 1/8" steerer, V-brake compatible, need a service. Keep meaning to ebay but have not got round to it, 3 years after their last use. If, after checking the above, they are useful, you are welcome to them for nothing.

[Andrew G]

Thanks chaps. The tape measure says it is a 1 1/8th headset and from what you've both said I think I'll try and keep an eye out for some 80s then - must have all been later models that I've seen so far, have to wait for something more retro . Thanks for the kind offer Elliot but it's probably best to go with 80s as it's my brother's old MTB and the frame is probably a size bigger than if I bought one new so I wouldn't want the front end any higher, it's already a touch higher than I'd like ideally.
[quote="Dombo"]Generally speaking they should not bottom out, as you absorb a lot of movement just flexing your arms.

[Grahame]

[url=http://cgi.ebay.co.uk/Pace-RC38-Air-Force-Race-Carbon-Suspension-Forks-Remote_W0QQitemZ270337582105QQcmdZViewItemQQptZUK_sportsleisure_cycling_bikeparts_SR?hash=item270337582105&_trksid=p3286.c0.m14&_trkparms=72%3A1688%7C66%3A2%7C65%3A12%7C39%3A1%7C240%3A1318]These[/url] may well be worth following up on.

I have a couple of pairs of their predecessors and they work well and have proved reliable for me. 70mm of travel should be about perfect, and being air sprung they are easily adjustable, and they'll be a bit lighter than Marzocchis as they are made of that funny plastic stuff that people seem to like having their frames made of.