Rear

The RD-M9100 XTR rear derailleur is intended for use with 1x drivetrains. It is compatible with both 11- and 12-speed cassettes. - Decreased rear derailleur tension at low gear position, to prevent high chain tension - Added bumper at rear derailleur pulley cage - Bigger 13T pulley - Direct mount compatible - Compatible cassette size: 10-51 (12-speed), 10-45 (11-speed) - Total capacity: 35t (GS Medium Cage) / 41t (SGS Long Cage)

Shimano Ultegra Di2 Shadow rear derailleur. - Sleek integrated appearance - New low-profile design - Shimano Shadow RD - Race endurance - Optimized slant angle - Maintain race concentration with more intuitive shift control - System communication with front derailleur - Shimano Synchronized Shift - Wide compatibility - Short cage covers: 11-25T to 11-30T - Medium cage covers: 11-28T to 11-34T - Average Weight: 242 grams (SS type), 249 grams (GS type)