Rear Derailleur M 12 Speed Shimano XTR Shadow+ RD-M9100-SGS

The Shimano XTR RD-M9100-SGS is the flagship of Shimano’s mountain bike range. The lightest, quietest, and highest-performing 12-speed derailleur they make. Built for cross-country, marathon, and enduro racers who want race-day precision without compromise.

At the heart of the M9100 is HYPERGLIDE+ shifting, which cuts gear-change time by around a third compared to previous HG drivetrains. Delivering fast, smooth, near-silent shifts in both directions, even under full pedalling load.

Oversized 13-tooth pulley wheels improve chain stability and reduce friction, while decreased chain tension in the lower gears keeps the drivetrain running quieter and more efficiently where it matters most.

The SHADOW RD+ clutch keeps the chain taut over rough terrain, cutting chain slap and the risk of drops, and a protective bumper on the pulley cage absorbs impacts and further quiets operation on aggressive trails.

As the long-cage (SGS) model, the RD-M9100-SGS is built for wide-range 1×12 setups. Compatible with Shimano’s 10-51T 12-speed cassette, and also the 10-45T Rhythm Step cassette for riders who prefer tighter gear steps.

Key specs:

• Speeds: 12
• Cage length: Long (SGS)
• Clutch: SHADOW RD+
• Cassette compatibility: 10-51T and 10-45T 12-speed
• Total capacity: 41T
• Pulley wheels: 13T (sealed bearings)
• Weight: 240g