Fork Suggestions For A 1996 Trek 850

[RonF]

I've got a Trek 850 that I think is from 1996 and it has a cruddy fork. I know the bike is worth little or nothing, but I do have sentimental attachment to it, and it's American made of True Temper steel, so I don't see a reason to simply discard it. The fork that is currently on it is apparently a basic Rock Shox that doesn't have any sort of model designation on it, and it appears to have really short travel. I would like to replace the fork with either a rigid fork or something that is tunable and is able to be rebuilt, if necessary. Based simply on age, should I be looking for a Rock Shox Mag or SID, or is there an alternate fork I should be looking for? I sort of ruled out the Judys because of reading about the elastomer bushings dissolving, or something. Based on proportions in the pictures I've seen, the Mag appears to have the same uncompressed length as my fork (~405mm a-c) while the SID seems longer (though I think I saw something in a Rock Shox service manual online about the SID having a settling height based on rider weight and how much air is in one of the chambers). I'm 135-140lbs and (at best) a novice rider that is likely to stick to well known local single track trails. If any of you guys can give me some suggestions about which fork I should be looking for, I would really appreciate it. Also, I'm trying to attach a link to a picture of my fork on Flickr - I don't know if its going to work or not...
http://www.flickr.com/photos/ihatesanity/3187735451/

[mark w]

Are there air valves under the top caps? If there are, that's likely a Mag 10, the non adjustable version of the Mag 21. If there aren't, it's likely a Quadra which is a non-damped, elastomer sprung fork. Travel on either one was ~63mm IIRC. The Quadras were/are relatively easy to work on but I doubt you can get replacement parts if anything inside is broken. If it's a Mag, you need special presses and pullers to service it. I used to have the tools but traded them away after I got rid of my last Mag fork. I'd probably recommend going to a basic steel fork if there's anything wrong with your fork beyond possibly needing lubrication. There aren't a whole lot of short A-C forks around these days and unless you can find a stellar deal on something NOS, going rigid is the better route IMO.

[RonF]

There aren't any air valves under the top caps. The top caps are plastic and were held on with some sort of adhesive and there are just hard plastic bits that look like they have been pushed down into the hollow, threaded center of the adjustment nut - mark_w, from your description, that sounds like a Quadra, right?

If I do find an old SID fork, it seems that seals are still available from Enduro Fork Seals and are replaced easily enough, but are there any other specialized gaskets or seals that are not available?

[Pinoy Rider]

I still ride my 1995 Stumpjumper. The original fork was a mag 21. I replaced it with a Marz Superfly and eventually put a SID XC(2000). A little lateral flex but overall I like the little extra travel.

[BottomBraket]

I need to follow this tread. I have a "trash-bin save" Diamondack apex with a Rock Shox Indy C. Last friday, in the cold, it felt like a rigid fork.

Any hints, advice, suggestions?

[RonF]

Hmmm... The more I look into it, the more it seems like a rigid fork is the way to go since the 'antique' Rock Shox route looks like it might take a lot of effort. That said, does anyone know where I can get a 413mm Vicious Cycles fork cheap?

[RonF]

Well, I was at the local Community Bikes and found a 2000 Rockshox Judy SL manufacturer sample unit in a corner that looks like it received very little use and sustained most of its scratches from being bounced around the shop. Based on the red springs that are in it, the owner's manual suggests it is set up for 63mm of travel, but I haven't gotten into the recoil dampers yet to see how the spacers are oriented. The uncompressed a-c length is something like 445mm, which seems like a big jump from the ~410mm a-c length that was on my old OEM Rockshox. Would it be a bad idea to use this fork, or would the added a-c length effect steering negatively?

I also contacted Vicious Cycles and Chris Kelly about fork recommendations and got very different answers. Vicious recommends a 413mm fork where Kelly recommended a 435mm fork.

So a rigid fork is still in the plan, but they are kind of costly, and this Judy SL in my hands is here, now, and cheap, but potentially too long. What do I do?

[riderx]

If it was me: Measure your current axle to crown and get rigid fork that is a reasonably close match.