Just quick one. I have used 9 speed chain rings and 9 speed chains on a 10 speed drive chain and they have been fine.

A mate in work has offered me a 9 speed XT rear mech and I'm just wondering if there is any reason why this is not going to work with 10 speed everything else,including shifters?

It'll work fine.

EDIT: Actually I've got a nagging doubt at the back of my head, didn't Shimano alter the pull ratio on 10spd stuff?

s8tannorm wrote:It'll work fine.

EDIT: Actually I've got a nagging doubt at the back of my head, didn't Shimano alter the pull ratio on 10spd stuff?

Hmmm It would seem from this (http://forums.mtbr.com/drivetrain-shift ... ost9074131) that:

Shimano 9 and 10 speed MTB rear derailleurs and shifters cannot be mixed in any combination!!!

This detail might be buried on the above links, but I think 9sp pulls cable on a 2:1 ratio, but 10sp pulls cable on a 1.9:1 ratio. You can get a 10sp mech to work on 9sp with a little riser block where the cable bolts to the mech to increase the ratio, but I don't think it works the t'other way around. Alternatively, get some thumbies, switch them to friction and run it with whatever mech and cassette you like :)

Ian wrote:This detail might be buried on the above links, but I think 9sp pulls cable on a 2:1 ratio, but 10sp pulls cable on a 1.9:1 ratio. You can get a 10sp mech to work on 9sp with a little riser block where the cable bolts to the mech to increase the ratio, but I don't think it works the t'other way around. Alternatively, get some thumbies, switch them to friction and run it with whatever mech and cassette you like :)

As simple as that.

Think I'll just buy a 10 speed when I need one and not try to do my mate a favour.