😕 Or is it just an ‘inexact art’?

well i guess if your next chain wears out at a super fast rate then you can guess its buggered – thats the expensive way of finding out like i did 🙁

I work on the old rule that if the outgoing chain has 0.5% stretch or more then the cassette goes with it.

if a new chain skips is the only way I know.

if a new chain skips is the only way I know

Yep, what TJ said.

Rohloff make a tool it costs about £20
http://www.rohloff.de/en/products/hg_ig_check/

I have 2-3 PG990 cassettes in my spares, but don’t know/can’t remember how many miles they’ve done (not that many is my guess!), guess I can just give each one a go with a new chain and see what happens!

I go by looking at the teeth and seeing if they have heavy indent/lips on the teeth

if it slips, it’s for the skip(s)

I think the general technique used on the classifieds is:

Look at it – if it still has teeth then its in good condition and has only covered 50 miles.

LOL @ David 🙂

APF

Does anyone really buy secondhand cassettes?