When to replace a crank?

[ZenSojourner]

How do you decide when you need to replace your crank?

Note that's NEED not want.

[DirtDiva]

When you see a better one for a really good price?

Generally, you just replace the parts of the crankset as the wear out. Chances are the bottom bracket will go first (unless you only ever ride in perfect weather) - usually there are squeaky noises and wobbly feelings giving you a clue here. Then you might wear the teeth of one or more of the chain rings to the point where replacement is a good idea. The crankarms themselves very seldom wear out, even if they can get pretty scruffy looking as the paint/anodizing wear off.

When I replaced the crankset on my mountain bike, it was because I had been chewing through isis bottom brackets at an alarming rate (like, less than three months) in the British winter and wanted to try a different system to see if it would be more durable.

[OakLeaf]

What's wrong with it now that makes you think it might need to be replaced?

I think at one time or another I've worn out or broken every component except for the cranks...

Oh, okay, the cranks and the stem.

[DebW]

The chainrings need replacing if the chain won't sit down in the valleys between the teeth.

[ZenSojourner]

I'm buying this:



And the guy at my LBS wants to replace EVERYTHING on it.

I just want to replace the rear cassette and the chain. And the seat. And the pedals. And the tires. And the bartape.

The components were all new in 1998 (crank, rear cassette, both derailleurs, STI shifters), the frame is from 1987 or 1988 (it's a Terry Despatch, lugged steel). Left shifter replaced in 2004. It has a Sun wheel on there. Actually what I'll probably do is buy a new wheel with a new cassette on it and use that one permanently mounted on a trainer (depending on the trainer, if that's appropriate)

The guy at the LBS is a gonzo mountain biker who replaces all his components every year. I just don't think that's appropriate in my case.

Owner says it shows "some wear" but it has less than 2k miles (on the chainrings)

I actually don't know if the bottom bracket was replaced when the crank was replaced. If not, after 20 years I'm sure it needs to be replaced by now.

$225 is the asking price. I don't see many used Terry's in my size.

[uforgot]

That bike is going to be a beauty! I like those cranks. Some of the newer ones just look ugly and flat to me. I'd listen to Deb. I'm not even close to expert, but why on earth can't you just replace the chainrings? I've noticed that some shop owners just don't care for the older bikes, and only want to deal with new new new, and others like them like we do. Can you find one who thinks that it's a lovely bike and doesn't want to take away it's character?