but compatible with any of Shimano’s other 11-speed road shifters. For flat bar setups, the RX can be paired with Shimano’s Metrea SL-U5000 shifter that is compatible with road rear derailleurs.

6-speed and 5-speed systems. With the development of 9 and now 10-speed cassettes it was necessary also to reduce tooth thickness, so 9 and 10-speed chains are incompatible with other systems.