Shimano XT Rear Derailleur 12 Speed RD-M8100-SGS### Shimano Says ### SHIMANO DEORE XT Rear Derailleur SHIMANO SHADOW RD+ 1x12 speed The all new SHIMANO DEORE XT M8100 series of derailleurs brings a new level of drivetrain silence thank to decreased tension in the low gear position and an added bumper on the pulley cage. Larger 13T pulleys increase efficiency and chain management while compatibility with SHIMANO's new 12 speed cassettes boosts range. FEATURES Fast and precise shifting performance