Jowdy

Howdy,

I'm doing a little project on an old mountain bike, and want to install a 32-tooth chain ring on the crank, nothing else. (And I'll be using four or five sprockets on the rear cassette.)

Of course, I don't want the chain to be inclined to slide off as I'm shifting the rear gears, so I'm wondering if anyone has a recommendation for such a chainring. I've read that most compatible chainrings (like Shimano's something-glide style) are machined to allow the chain to shift easily off the chain ring when changing gears.

So, to distill: What's a good non-shifting 32-tooth chainring compatible with the five-bold pattern of my Shimano STX crankset?

Thanks for your help.

Jowdy

JiveTurkey

Do you know what the bolt circle diameter (BCD) of the crank is, specifically for the middle chainring? See here: https://sheldonbrown.com/harris/chainrings.html

I'm guessing 110mm. In that case, the smallest chainring that will work is 33T, which is rare (https://www.sheldonbrown.com/harris/chainrings/110.html). Should be able to easily find a single-speed 34T chainring, such as https://www.universalcycles.com/shopp...s.php?id=16021 Just make sure it is for 3/32" NOT 1/8" chain.

If the middle and outer chainring positions are 110 BCD, the inner chainring spot will likely take 74mm BCD, which can take a 32T. You'd probably want to get a longer bottom bracket so that the new chainline of the inner chainring can be similar to the original chainlline of the middle chainring.

If you do have a 110mm BCD crank, I suggest just using a 34T and adjusting the size of your cogs to accommodate the slightly higher gearing.

LWaB

There were some older STX cranks that had unique chainrings. Without a model number or photo, it is difficult to give definitive advice.

Ingleside

A non-ramped chainring like the one Salsa makes should work out for you. As far as I know STX cranks used a 94/58 bolt pattern.

https://www.universalcycles.com/shopp...7&category=649

Jowdy

All,

Big thanks for the feedback; this all points me in good directions.

And, Turkey, thanks for the brief breakdown of complexities to consider. It helps as I slowly gain an applicable vocabulary for this stuff.

j

Iowegian

+1

LarDasse74

I also recall STX or STX-RC having an odd pattern... maybe the right BCD for some standard size, but standard rings still didn't fit very well.

Mr IGH

If you go with a Surly, be sure to add a bash guard. If you're not going to add a bash guard, Surly isn't a good choice, look for a beefy aluminum chainring.