Shimano Deore XT RD M8000 11 Speed Rear Derailleur. Shimano Deore XT has made the jump to 11 speed with their new M8000 groupset and a key element in making the drivetrain smoother, crisper, and more reliable is the rear derailleur. Featuring a GS version for single or double crankset drivetrains and an SGS edition for a triple crankset, the new Deore XT RD M8000 rear derailleur has been redesigned with a lighter shift than its predecessor 20% less force is required to move the chain and it does more efficiently so every shift feels smoother and easier. The all new Shadow design with an optimized slant angle helps keep the chain perfectly tensioned and stable plus features an easy to adjust design via an allen wrench. Additionally, the pulleys and jockey wheels feature a new tooth design to reduce friction and make every pedal stroke more efficient.