Tell me more ×  I bought a new road bike with Campag Athena 11
speed in March last year. To the end of Jan it had covered
9000km.  In all that time I hadn't changed the chain because I
don't have the Campag tool, and the KMC chain was not available.
I finally got a new chain recently - unsurprisingly the old one
was very stretched - so I bought a new cassette as well.  The
thing is, the new chain on the old cassette runs very smoothly,
and even dismantling them and comparing the cogs I can't see any
change in shape or size! I don't know what Campag are making
them out of, but it's fantastic stuff.  Everyone I've spoken to
is convinced that after 9000km on one chain the cassette will be
useless, but the prevailing advice is also to change the
cassette when there are issues, and there just don't seem to be
any.  share|improve this question If there's no obvious wear I'd
be tempted to leave it. When I fitted a new chain onto what
turned out to be an obviously worn cassette the chain still
skipped quite a lot. – 