Originally Posted by
Broctoon
If I had a 7-speed drivetrain and wanted to upgrade, I'd skip right over 8 and 9, and go with 10 speeds. In fact, that's what I did, with an old Trek 1100 a few years ago. It is not *that much* more expensive. It's immeasurably more work than continuing with your current setup, but about the same amount of work as going up to 8 speed.
Agree with 8sp not worth the trouble over 7sp but spreading the dropouts 5mm for 135mm is not as trivial as it sounds. Even steel dropouts resent it like hell. What about a Road hub though? I believe 10sp Road hubs are 130mm OLD. Rear derailleur and shifter would have to go though.