Apologies to all who took the time to answer my gear slipping/crunching query. Turns out the problem was 'mechanic' error. Or more accurately, I hadn't done up the cassette lockring tight enough, which I discovered when taking it off to fit the new cassette I'd bought to replace it. So at least I have a spare cassette now.
Apologies to all who took the time to answer my gear slipping/crunching query. Turns out the problem was 'mechanic' error. Or more accurately, I hadn't done up the cassette lockring tight enough, which I discovered when taking it off to fit the new cassette I'd bought to replace it. So at least I have a spare cassette now.