I picked up an old (best I can date it is 1996) GT Outpost to discover it has issues going into 1st, it binds. upon further examination, the 1st gear chainring (CR) has some splits on a few teeth. I didn't know what to look for in bikes since I am fairly new to riding, so I missed it. Now I do. the CR appears to be welded together as I do NOT see bolts holding the 3 rings together. Will the whole crank need to be replaced? I was hoping to use this as a road bike (it is similar in form to road bikes) and save the mtn bike for off-roading. I tried looking for a crank for it, but it is difficult due to the age. of course I never worked on a bike before as well. is it worth repairing? or just cut my losses? Thanks for any assistance.

picture is of an identical looking bike

Finding a crank for it is not difficult due to its age.

If that is an old model Shimano/SR crank (which did come with pressed/welded rings, by the way), the splits in the chainring are very likely forming done to improve shifting...which would mean: there's nothing wrong.

Unfortunately, without a picture of the side of the crank that matters...

ok, what will fit? cost? I got the bike for under 100. I can get more detailed pictures later but it looks like all the CRs are welded together as 1 piece and why I think the whole crank needs to be replaced. I don't recall how the CRs are attached to the crank.

oh it's BAD. once the chain gets on the splits, it BINDS and throws the chain OFF. the splits are BAD. when I test rode it, it never occurred to drop into 1st gear because I didn't need to. but once I tried a hill, OOPS!

I don't think you understand what you are being told. It's very likely those "splits" you are describing are an intentional part of the chainring's design and are there to improve shifting. It's far more likely the front derailleur needs to be adjusted to shift properly and/or the cables and housing are dirty and should be replaced.

A good, sharp detailed closeup of the crank would make it a lot easier to see what's going on.

Agreed that we need more info to be more specific in our attempts to help. Photos, yes, but also a better description to what is meant by "binding". When diagnosing bikes it helps to separate the various functions. So does the crank spin smoothly and without rapid slowing down (as in tight/rough/binding BB bearings), removing the chain from the CR while giving the crank a spin separates a chain issue from one of the crank/BB. Are the CRs wobbly when the crank is not spinning? Are they so when the crank does spin? Do all the CR teeth follow each other in line or are some bent to one side? Does the ft der have a full and in impeded movement? Do this by pulling on the exposed cable to separate the der from the shifter function. Is the ft der properly positioned WRT the CR? Looking up on line vids to see how ft ders are adjusted helps here. Is the chain in good shape? Any non moving links? Any twisted links? These are but some of the ways to try to figure out what might be going on.


All of these and other methods of diagnose are done in only a few minutes by experienced mechanics. If you can't understand these methods then you might be best served in going to a LBS and asking them for an assessment/estimate. For all their simplicity ft ders are actually rather complex in their set up and function. Andy.

The smallest chainring on a crankset generally isn't going to have much in the way of shaped teeth or shifting aids. Those are necessary to lift a chain from a lower chainring and since there isn't a lower chainring than the inner, those aids simply aren't needed on the inner ring. If you see "splits" on that small chainring, there's a decent chance they're damage and not there by design. (I'm speaking in generalities, but it really would be nice to see a decent pic to confirm.)

If the crankset needs replacing, a replacement crankset is easy to find. Eyeballing the crankset, I'm guessing it's a 28/38/48 triple. (Since the picture's taken from the non-drive side, I'm not 100% sure on that, so you'll need to count teeth to be certain.) And if the bike's the same size as the one pictured, the crank arms are probably 170 mm in length. Inexpensive replacement options would include Shimano FC-M311 or FC-M171 cranksets, which can be found online for about $20. Both of those cranksets are designed to use a 122.5 mm bottom bracket, so add a Shimano UN-55 bottom bracket in that length for another $20 or so.

If you don't have the tools to replace square taper cranks and Shimano splined bottom brackets, you may need to buy a couple of tools as well. A Park Tool CWP-7 crank puller will cost you $15-20. A Park Tool BBT-32 bottom bracket tool will set you back about $15.

Have you compared the rings to another bicycle?
A picture of the "splits" would show exactly what we need to know.

A lot of Shimano cranks from that era had shifting ramps formed by what looks like tears in the chainring.

I'm guessing something else is wrong with it.

Could be bent rings, or improperly setup or damaged front derailleur. I'd check those first.

If you decide crank is toast,
Replacements are available at Niagara Bikes. You'll want something with similar teeth counts to simplify things. The one in the photo loos like it has pretty big rings, 28/38/48 perhaps.

You'll probably want a Shimano A-group Altus/Acera/Alivio. You need to get proper interface, probably square taper. You'll have to check current BB spindle length to see if new crank compatible with existing BB, or just get new BB with crank.

I have been riding a 1996 GT Outpost for twenty years. The one in the photo appears to be the same general vintage, but not the same year. In any event, the front chain rings ARE welded together, so you would need to replace the whole crankset. I just replaced mine with a 3-ring set made by Acer for $40, which included a 5-minute installation that saved me getting my hands dirty. The package includes the chainring set and the two cranks (arms that hold the pedals). You need some bike-specific tools to replace it, so it might be worth playing dumb and asking the bike shop mechanic to put it on for you.

Great bike, that GT Outpost. I have put hundreds of dollars into mine over the years only because I don't ever want to ride anything else!

see attached. here you can see how the chain binds after it goes into 1st gear.

in the 1st picture, you can see the split tooth in 1st gear.

Where in your photos are the splits?

Can't see any broken teeth from the photos. Rings and chain look very dry and dirty.

see attached

are these teeth broken?

The ones on the big ring are a "shift gate" -- intentionally shortened to aid shifting. The other two rings look like they do have some problems, though. A file could take care of the weird "split" on the small ring's funky tooth. The middle ring, though... I'd probably toss the crankset.

If you're looking for something on the cheap, I've got a similar-quality Sakae XCT crankset I'll never use. Same 28/38/48 chainring configuration. I can send it to you for the cost of shipping.

This crankset is quite worn and, as mentioned, has some damaged teeth. While some of these issues are sort of correctable the best long term solution is to replace the crankset. Know that while matching the teeth counts is very possible the new crankset might not be best mated to the old BB (and a BB as old as this crankset might be well wore anyway.)


The chain being lifted up and "behind" the small ring is what we call chain suck (google it). This can happen because of well worn teeth which allows the chain to no longer sit in the tooth valley and release off it as intended (often made worse by shifting under pedal power) or from teeth that are bent/damaged in a way that the chain gets hooked on then and doesn't release.


That this crankset shows multiple issues and will only increase wear on other parts like the chain. I vote for replacing it. Andy

That's a pretty cool old bike. I'd toss the chainset in the recycling and try and find a replacement on ebay.

Assuming you need a new crankset (three chain rings and two pedal arms), this is not as big a project as you might think it is. As I mentioned earlier, I replaced the crankset on my 1996 GT Outpost a few months ago and the part was readily available at a local bike shop. The whole thing, with installation, cost me $40.

If you have trouble finding one, call Dan at Visentin Bike Pro Shop in Oyster Bay, NY at 516-922-2150 and he can probably ship you one.

Chain suck!!! that's definitely it! It's only recently that I got into multi-geared bikes so it's new to me. Should I file that "split" tooth on 1st gear and try it again? or just take it to a shop & get their opinion? the odd 2nd gear teeth may be normal as I saw others that looked like it. also there seems to be a lot of slack in the chain, should I take out a link or two?

It is more likely that the chain suck is happening on your middle ring, not the small one
Remove chain links only if you are sure that after they have been removed you can still switch gears to the largest rear cog while your chain is on the big ring in front without destroying your rear derailleur. If you remove links from a properly sized chain you are asking for trouble

Well. Taking a problem to those who deal with them daily is always a good way to get info. Andy

Nice ride, try to find a used bike store they can hook you up with the same thing or an upgrade very cheaply. Probably in the range of $5-$20.