Chain/drivetrain life

[lph]

My understanding is that you replace the chain and cassette (at the same time, because they "wear together" - though I know a few who insist you can run 2 chains to 1 cassette) early enough to save wear on the more expensive chainrings.

Once the chainrings are worn you replace them too. You can replace them individually on some bikes, not on all. And then you should replace the chain and cassette at the same time.

The upside is you then have a brand-new drivetrain, which is great!

[maillotpois]

lph is generally right, but I will generally go through 2 -3 chains before I need a cassette change - with a SUPER thorough cleaning of the cassette and checking for wear when changing the chain.

I've gone through about 4 cassettes and 8 chains on one bike (replacing chain at 2500 or so miles, when stretched) before needing to replace rings. Even then, you may not need to replace all the rings, just the ones that are most worn.

[lph]

lph is generally right, but I will generally go through 2 -3 chains before I need a cassette change

Oh good. I've always thought that theory made sense, but every time I mention it at the lbs somebody tries to talk me out of it...