Originally Posted by
noglider
Yes, it's clear now. I don't track my miles, so I don't know how long anything lasts. I have too many bikes and don't ride enough, so I probably don't have 8,000 miles on anything.
Still, I'd prefer to forestall cassette replacement, especially with expensive cassettes such as 9-speeds. If that means "wasting" chains, I'm OK with that. Replacing them prematurely is one of the few environmentally-unfriendly things I do. It saves a lot of solvent handling and dirty scrubbing.
I think you still missed something. Changing chains made NO DIFFERENCE. My cassette still had to be replaced in the same number of miles.
The cassette was surely more worn out at that point, but it didn't matter because the chain was worn out too and they matched. At the end I replaced the cassette at 9000 miles either way.