Chainring replacement
 

http://bikeforums.net/attachment.php...hmentid=513947

Does my chainring SR Suntour 175mm crankset need to be replaced? And if so, can I replace it with an easier to find brand if it's in the same 52/42/30 configuration?

Those look pretty good to me, and I think I'd run 'em as they are.

Replacing with another brand should be ok. The bolt circle diameter (BCD) is what to watch for. You need five-bolt rings at whatever BCD fits your crank arms.

I don't know, they look pretty bad to me. If this were a motorcycle, definitely replace. can't address your replacement question though.

What makes you think the rings needs replacement? If they really need replacement, or you want to change your gearing, they can be replaced individually; you just need to match the "bold circle diameter" (aka "BCD") for them to work. It looks like your crank has the two outer rings the same BCD (probably 130mm) and a smaller BCD for the inner ring (probably 74mm).

It looks okay to me, Bear in mind that what appear to be worn teeth are actually shift points. If you examine the rings closely, you will see that the shorter teeth are mimicked on the opposite side of the ring as well.

bolt, not bold...

if shifting isn't a problem, don't bother changing the rings.

That's what I was referring to, not sure, as a novice, it just looks like about eight potentially troublesome teeth on the third chain ring.

It's a shift/chain release point. Look at the short teeth where the ring is engraved with the size. Then look at the middle ring in the same area; you'll see shorter teeth there as well. There are none on the small ring because on that ring the chain only needs to shift up and not down.

Yeah, it's "bolt circle diameter", this coming from one who NEVER makes a typo. ;)

I'm pretty sure the outer BCD is 110 mm, not 130 mm and agree the inner is almost certainly 74 mm.

No, none of it needs replacing.

Much to learn, and, understand. Thanks.

That's what I get for trying to make supper at the same time. :notamused:

The points don't wear that much.

The valleys get wider, so that the chain gets purchase on fewer teeth at a time.

You can check somewhat by lifting the chain where it is wrapped around the chainring- good condition = little slack,

poor condition = chain lifts away from the chainring (this also reflects on the state of the chain).

Try it on the different rings- the middle gets the most wear typically.