SeraphimF

I've seen a few threads on this but nothing too conclusive. I just got a Gary Fisher Aquila on Craigslist for $40 (for some reason, it is in appreciable shape and has no visible deficiencies under the conditions I've ridden it so far). I'm planning on using it as a utility bike/commuter when the time comes, but the fatal flaw is the suspension fork. I kind of like it -- it doesn't really slow me down much, but it has no attachment points and the bulk of the shocks gets in the way of mounting a wald basket through the quick release.

I figure a steel or cro-mo fork that needs no special qualities can be had on ebay for cheap enough, but all the threads I found talk about how it will "change the geometry of the bike". How will it change? I'm not particularly drawn to the geometry of this bike (although it does fit like a dream), so if it changes and isn't some geometrical monstrosity, who cares? Any specific info on what kind of changes this will bring, specific forks that can be recommended for a smooth transition, or any other info? It isn't going to need to perform at some high level, just hold the wheel and a basket and not bring me closer to death. Current setup is threaded and I'd like to keep it that way.

Trevtassie

Get a Surly Troll Fork in 100mm suspension corrected. Yeah, it'll cost way more than the bike, but they have every attachment point you could ever want, plus a few you didn't know about... If you run non-corrected forks it'll do the following: Steepen the fork rake and make the bike twitchy, shorten the wheelbase making it twitchy, drop the bars down so you need a higher stem. Probably the most critical thing it'll do is drop the bottom bracket height to a point where pedal strike becomes a real problem.
As for keeping it threaded, you'd need to find a set of forks with the same height headtube or get a threadless fork threaded, which would probably cost more than buying or scrounging a threadless headset and stem. You might be able to find those at your local bike kitchen.

Oneder

You need more clearance for a shock so if you change to a standard fixed fork you will lose some height in the front, which you may or may not want. The real issue is you have to find out the proper size fork, and they are not always available new any more. So for that reason I would try and avoid messing with fork on an old bike, but you could probably pick up another cheap mountain bike for the fork if you know it's compatible.

Ironfish653

Yup. You'll want to find a fork that has the same Axle-to-Crown length. (Really the axle, to the bottom bearing race)
Generally, in the mid-90's when suspension forks became more common, and over the years, as travel increased, head tube length decreased, height increased, and moved forward to accommodate forks with 100mm of travel, so a rigid replacement has to keep all of that in mind, to keep the front wheel in the right place.

A bike like a cruiser, with no suspension, will have much longer head tube and shorter fork legs than a long travel MTB even if they both have 26" wheels.. Using a cruiser fork on a long-travel MTB will cause a lot of the problems that are mentioned in Post#2.
An early-90's MTB will probably be less trouble to fit with a generic 26" fork, but still try to find one with as close to the same length as the original.

SeraphimF

I would have found this a ridiculous prospect not long ago but I really like riding this bike, which makes me feel a little better about putting some loot into it. I actually have a threadless stem to spare, but that means new bars...it never ends! swept back bars in 31.8 that are cheap seem like a hot commodity. I will also have spare flat mtb 31.8 bars but I hate flat bars, might do for the time being depending on prices of swept back bars I find. I appreciate the geometrical info from you and the other users, but still have other questions: is this fork basically guaranteed to be accommodating to my bike? Are there more factors to keep in mind? I will have a talk with the LBS here but I haven't been to them before and I live in an area where my expectation is that its a family cycling cruisers and nothing else kind of place. I've had very unhelpful LBS people in the past so its something I'm trying to cover in advance.

EDIT: Bonus is that this will fork will uglify it to a degree where I will feel more comfortable locking it outside!

skidder

Bike Nashbar sells a suspension-corrected rigid fork for $50. It heavy, but no heavier than a suspension fork. I'm using one on an old MTB I converted to a utilitarian street bicycle and its been working fine for the past few years. I think the Nashbar fork is for replacing 100mm travel forks, but mine was an old 80mm travel fork. It made a tiny bit of difference in the seat angle, and the steering seems a little floppy (it won't steer straight by itself if I take my hands off the handlebars while riding it), but not enough to discourage me from using it. Longest ride I've done on it was 35 miles (on pavement) and no issues.

Oneder

When I was talking about fit I did not mean the length of the fork. Typically if you get a new fork then you cut the tube to fit your frame. You probably can't get a new fork for that bike any more though. So you have to find one used that is the right diameter and type to fit your frame and also has enough length. So it's kind of a complicated prospect.

SeraphimF

Very helpful explanation! I am probably going to go with the Surly fork so as to give less of a chance of messing up but still have a few questions if you can help. First, how do I measure axle to bottom bearing? I assume bottom bearing=bottom bracket? Is it simply the height difference? i.e. if I drew a horizontal line from the BB, how much higher would I have to go to get to the axle?

Second, what exactly is "travel"? I hear it mentioned often but don't know what it is.

Although leaning towards the Surly, I'd be interested to know if a similar measurement rigid MTB from the same time period is likely to have a compatible fork, or if its a better bet to just go with the Surly fork and have that be that.

SeraphimF

Can you link to it? I'll try to look but that always helps. Also, I'm getting the idea that "travel" is just how long the shocks are? Is this true? Is it simple to just measure the travel, or should I try to find the specs.

Edit: found it. Looks pretty good and also has good attachment points, so putting it into consideration.

Ironfish653

No problem. The 'bottom bearing' is the Lower Headset Bearing. All headsets have a bearing at the top and bottom of the headtube; on an older bike like your Fisher, you'll be able to see the bearing race as a black or silver band between the top of the fork, and the bottom of the headtube. Measure from that band to the axle, +/- 5mm.
Basically, it's the overall length of the fork legs.

Travel refers to how much a suspension for allows the wheel to move up and down. 'Short travel' refers to the earlier 2"-3" travel forks, the current generations are long travel, 100mm+ (4"+) This refers to MTB forks, with short travel forks most commonly found on 26" bikes, and long-travel being the realm of the 29ers. More travel increases the axle to crown length.
Confusing things, a lot of hybrids are using short (<2") travel 'comfort forks'

Your bike is most likely an early-2000s, so we're talking about a classic short-travel 26" bike.

Trevtassie

If you don't want to run lowrider racks using midfork eyelets I'd go the Nashbar, $49.99 including postage is a good deal. Throw in one of these stems for 25.4 bars and you are set https://www.bikenashbar.com/cycling/...e-stem-ns-atms

SeraphimF

I was going that direction too. I will probably attach one of those racks that attaches at the same spot that the canti breaks do. Just want to make double sure about the travel of my fork before I go for it but it seems like the way to go.

SeraphimF

Very helpful again, thanks a lot. Assuming it is a 2-3" travel fork, its a bit harder to find a suspension-corrected fork to replace it, since most are for 100mm instead of 80. Bit of research I did suggested 440mm axle to crown on a fork replacing a suspension fork with 80mm travel, sound right? I know the fork is a Rock Shox Indy, some of which have as low as 40 something mm of travel. in that case (I'll check the model and travel amount when I get home) would it be easier to just go for a non-corrected fork?

LesterOfPuppets

You said it's a threaded fork. First you have to determine steerer diameter. 1" or 1-1/8". Then you have to decide if you really want to keep it threaded, since that makes buying forks a little more difficult - 1. Is the fork's steerer long enough? 2. If the steerer is a little longer than needed, does the threading go down far enough?

As for ATC length, Yeah, fork travel probably gonna be 62mm travel or so. They might have made some 80mm travel threaded forks, but I dunno. 425-440 ATC might be OK

Got any pics of bike?

MAK

I did this on my Gary Fisher Nirvana and it came out great. The Surly Troll fork also saved me two or three pounds and as said above, has almost too many attachment points.