Chain+Cassette worn, what about crank wear?

alarustic

I've put 4000 miles on my bike throughout this year from new. To date, I've replace nothing. I assume if I replace the chain now I'll have to change the cassette, too. I read elsewhere I should've changed the chain way before now to save the cassette from wear.

I'm wondering if I should just keep riding it until the chain fails or whether I risk damaging the teeth on the crank, too? I see they're expensive to replace! I don't see the point in changing the chain+cassette during the winter months if I can leave them until spring.

I would appreciate your advice.

Wirral_paul

There's a lot more teeth on the chain rings to spread the load and so unless you can see signs of "hooking" to the teeth then i'd replace the cassette and chain and see how it goes. At 4k miles - i'd expect your chain rings to be ok - so how they run with a new chain. Some of the teeth are likely to be shaped differently (ie looking like the tips are missing) but that likely the design to aid shifting.

keef66

The longer you leave it as it is, the greater the chance you'll wear the chainring teeth. You could just leave the whole lot to wear out together until it actually starts skipping under load. By then you'll probably need new chain, cassette and chainrings. That's the state my old MTB was in when it was nicked, so I was somewhat cheered up by the possibility of the thief crushing his nuts on the top tube.

If it were mine I'd replace chain and cassette now, and start checking for chain wear more frequently in future. I replace my chains at 0.75% wear and so far the original 105 cassette has done about 6000 miles.

Bobbinogs

I would determine if the chain needed changing by either measuring or by using a gauge. Just going by mileage is a fairly crass and inaccurate way of working that out.

Like Keef66 I normally change at .75% but running a chain beyond that won't kill everything else. If you chain needs changing now then change it. If the cassette is skipping when you change the chain then change the cassette. IME, the chainrings will last forever unless you abuse them (my ALAN has the original chainring set from '89).

easyup

Do you ride in the wet, dirt, lots of climbing, cross chain, regularly clean/lube? These and other factors determine chain life, which determine cassette and ring life. On my road bikes with good mid-level components I change chains as they "stretch" to 12 1/16", measured under tension, and would think something wrong if I only get 4,000 out of it. I usually get 3 or 4 chain changes before the cassette skips and countless number of changes before ring teeth start looking like shark fins and need attention. But most of my riding is in flat, dry, clean roads in Arizona and I religiously wipe down my chain, chain rings, pulleys and floss my cassette after 20 to 40 mile rides. As they say, your mileage may vary.

alarustic

easyup wrote:

Do you ride in the wet, dirt, lots of climbing, cross chain, regularly clean/lube?

Ride in wet - yes
Ride in dirt - no
Climbing - lots
Cross chain - no
Clean chain regularly - no
Lube chain regularly - yes

Based on the advice in earlier posts I've ordered a chain wear tool so I can check the condition for myself. Once I know I'll decide what needs replacing. In future, I'll be a bit more interested in this side of things!