Mr. Underbridge

I'm helping out a neighbor with his bike, and he's let it go waaaaay too long on the current chain. We're talking 1/4" of stretch over 12 links (I measured 3 times because I couldn't believe it). So clearly the rear cluster is toast, but I have a spare (and identical) rear cluster, and chains are cheap. So no worries.

However, his crankset is of the riveted variety, so if that's toast it'll probably cost more than this particular ride is worth. Can't just replace the middle ring.

Question is, how do you tell when a chainrings is past the point of no return? I'm kind of hoping that because they're steel they might be OK. Is there any way to look at how many links on an unworn chain will lay on the chainring with no daylight under them? Or should I just grab a new chain, throw on my less worn cluster, and see if it works?

Thanks!

Re-Cycle

If the chainrings are steel there is almost no way they are worn out. If they are aluminum there is a good chance they are not worn out. Keep in mind that there is a lot more chain wrap on the chainring then the rear cluster so not only do chainrings wear slower but they are less sensitive to wear. My suggestion is to clean the chainrings and go for a new chain / cluster.

MudPie

I wore out the 22T granny ring on a mountain bike, and the tooth profile was like "shark fins". I say go ahead and replace the chain and cluster and give it a go.

z415

I would go for it and see.