Rear

Shimano's Dura-Ace Rear Derailleur boasts a light and reliable cold-forged-aluminum body with a carbon cage and a wide pivot design that boosts rigidity for smooth, speedy shifts. Fluorine-coated pivots minimize friction for nearly effortless shifting. And, the oversize sealed-bearing pulleys are silky smooth, ultra quiet, and keep out dirt and water. Plus, the 7900 accepts up to a 28-tooth cassette cog for even greater gearing possibilities.

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)