How can I tell whether my cassette needs replacing?

tgotb

My commuter's just over a year old, around 7000 miles on the clock, and I think it must be on its 5th chain or thereabouts. My commute's pretty flat, so I probably do most of my riding on the same two or three sprockets. I'm about to replace the chain again (stretch just over 0.75%) but how can I tell whether or not to replace the cassette too? Is it as simple as replacing the chain and then seeing whether it skips?

I have the new cassette ready to go, but am reluctant to replace it earlier than necessary, especially as January's not the best month for drive chain longevity...

nicklouse

Is it as simple as replacing the chain and then seeing whether it skips?

basically yes.

Sheldon has some thoughts and pictures on this as well.

tgotb

Thanks, excellent pointer.

For the benefit of anyone else following the thread, here's the link:
http://sheldonbrown.com/chains.html

saladdays

Commuting in London in all weathers means I change my cassette every two SRAM chains or so; about 5500M.

jeremyrundle

You need a special tool to fit a casette don't you

Blue Meanie

Only if it's a special cassette. Shimano and Sram use the standard HG Lockring tool, and a chainwhip to remove the old cassette. I still have an infamous Hypercraker, well known for cracking frames.

Do rhetorical questions need question marks (?)