Hi All,

I’m keen to drop my 38T outer chain ring down to a 36 / 34 / 32T ring. Race face seem to have 36 + 34T options but i’m not sure if they offer a true 2×10 outer ring in either size. also, will it effect my M785 2×10 Front mech if i drop sizes?

Any input welcome, thanks

I swapped out a 32t Shimano XT FCM770-10 speed ring for a 36t SLX 9 speed and noticed no change in shifting performance.

You can always drop the front mech a mm or two if it’s a problem, I’m currently running a M785 2×10 with 24 -36 rings.

Your front mech will be fine…

However your cranks will not. You’ll need to swap them for a conventional triple, but ditch the outer and middle rings and put a middle of your choice on instead.

dirtydog, you’re running the same m785 double cranks as me. Is your 36t ring the SLX 9 spd you mention?

No mate, I’m running triple M770 10 speed cranks with the M785 double specific mech, 24 – 36 rings and bash. The 36t is a 9 speed SLX middle ring and it works fine with my 10 speed setup.

I’m not sure what the issue with your crank is, Mboy?

I’m not sure what the issue with your crank is, Mboy?

The OP is running XT double cranks currently. Smallest “big” ring they can take is a 38T.

If he switches to conventional triple cranks such as you and I run, he can run whatever size middle chainring he likes down to a 32T.

On an XT double the smallest is a 33t, otherwise the chain fouls the tabs in the outer position