10/09/2026
This Shimano XTR RD-M951 from 1998 represents a different era with RapidRise. Unlike traditional high-normal derailleurs that default to the smallest cog under relaxed cable tension, a RapidRise derailleur rests on the largest cog when the cable is loose. The intention was to make you "start" in low-normal and have gear ratio increase with torque. A genius idea which ultimately failed because both riders and mechanics have very developed muscle memory and a system which works in opposite was said to be unnatural.
