A mate wants to fit one of the new 10spd doubles (a 26/38 SLX or XT) to his Shimano 9spd bike.
- does it need a 10spd double-specific front mech? If so, will this work okay with a 9spd LH shifter? Or will it be okay with a 9spd double mech?
- will the rings be okay with a 9spd chain, or will they need spacing out a tad? Or should I just fit a 10spd chain?