I have not replaced my rear campag cassette since I purchased the groupset back in 2009, but wanted to know whether they will still wear even if you do replace your chain frequently.

Trying to understand whether this could be one of the reasons why the shifting on my bike has started to become really temperamental. I adjust the indexing, but it never seems to stay indexed correctly and over the course of a ride it will drift out and shifting become problematic.

Not sure about your shifting but yes, a cassette will still wear even with a new chain but it will happen much slower than it would with an old chain. I do about 4 or 5 chains to a cassette.

Short answer: Yes, but not as quick.

Yes.

Over time your old chain would have worn into the cassette, meaning that when you’ve changed to your new chain it will go into the same grooves left by your old chain! Which can wear your chain prematurely and might be the cause of the slipping! Hope that helps!

No – cassettes becoem everlasting if you replace the chains!

Seriously, yes. But your issue is likely to be mech wear or cable stiffness.

Road bike components, (which I assume it is as it’s Campag) wear WAY slower than MTB bits, especially if you don’t use it in filthy weather. But for inconsistent indexing, I’d be changing the cable first.

edit – beaten to it!