[Closed] 9 and 10 speed MTB rear mechs...

The only combination that works is this, a 10spd Shimano mech with a 9spd Sram shifter. You may need a 6mm spacer under the cable clamp on the mech.

As above, as the actuation ratio is slightly different on 10 speed mechs compared to 9 speed. I've heard of some people having trouble with the above combo as well, though it can be got to work (it works as sram and shimano systems have different ratios, and this difference basically cancels out when you run the above 9/10 combination).

Ah yes, I remember now. Thanks

8 and 9 speed are compatible aren't they?

Yep that works fine IIRC, mechs have the same ratios.