Originally Posted by
JiveTurkey
For Shimano, the FDs between road and MTB are not compatible (different cable pull ratios). Since SRAM road FD & Shimano road FD are compatible and SRAM MTB FD & Shimano MTB FD are compatible, that leads me to believe SRAM road FDs won't work with MTB shifters.
SRAM road RDs use the same 1:1 ("exact actuation") cable pull ratio as SRAM MTB RDs, so they are interchangeable. But you should look out for max cog and total capacity.
Are you sure that SRAM Road rear ders are 1:1? That's great because I have a project in mind. As far as SRAM off road rear ders. go, some are 1:1 and some are 2:1 to be compatible with Shimano drive trains. X.7, X.9 X.0 are all 1:1 as are their shifters. most others are 2:1 as are their shifters. If indeed the SRAM road ders are 1:1, you would have to mate them with one of the 1:1 shifters. The SRAM off road rear der is the most robust I have used. Why would you substitute a road der for that? What advantage would there be? I'm just curious. Those X.9s are just about bulletproof.