Rival 1 rear derailleur type 21 the sram rival 1 x horizon rear derailleur is engineered for smooth reliable shifting action by eliminating unwanted chain movement x horizon shifts faster puts an end to ghost shifting and reduces shift force and chain slap 11 speed 269g colours black outer cage aluminum ccage sizes medium 11 26 through 11 36 and long 10 42 x sync pull x actuation