I want to fit a SRAM type 2 or Shimano clutch rear mech (that only seem to come in 10 speed) but have a 9 speed cassette and shifter - can it work if the limiter screws are set ok or will the ratio be out as it is designed to shift a narrower chain less far? Can't really justify a whole new groupset!
The ratio is different.
You can use a shimano clutch mech with a spacer under the cable bolt point and a 9speed sram shifter apparently. Google for it, it's been talked about on here and there's a pinkbike article.
But if you don't already have a sram shifter, you need a shifter anyhow so all it saves you is a cassette and chain... in which case why not just wait till they wear out? If that's not going to be soon, ride your bike more!
Thanks IA, as I thought. Guess it will be the upgrade......, which should be after a beasting at Tweedlove!