To run a 1x11 drivetrain with the Shimano XT M8000 11 speed system your best options for wide range gearing are the 11-42 and 11-46 cassettes. The M8000-GS and SGS 11 Speed Rear Derailleurs have been designed with the specific requirements of a 1x system in mind. At the same time, the same principles hold for the 2x11 speed drivetrain with the 11-40 cassette. You want maximum chain retention both at the cassette and on the front ring or rings. Shifting needs to be fast, precise, and wholly reliable. This is XT, and every aspect of the this derailleur has been re-engineered to follow the XTR example, at a much more reasonable cost.

The Shadow RD+ design, which keeps the overall derailleur profile very close to the bike in all gearing positions, has been redesigned with a shallow slant angle, keeping the cage more towards the cassette, for increased gear stability and consistent shifts. Combined with an improved clutch tension adjustment, the slant delivers excellent chain wrap and positive force on the derailleur when engaged, meaning no chain bounce, and virtually zero chance of chain drop. The shifting performance has also improved, and when used with the new M8000 11 speed shifter, precision shifts have never been more consistent.

Cable routing is clean and direct to the derailleur, and the high efficiency pulleys offer tremendous durability and very low chain resistance. The M8000 Rear Derailleur comes with the conventional bolt mount system, but is compatible (when used with an adapter kit) with direct mount frames. Short of XTR you won't find a higher performing, low profile derailleur this durable and precise anywhere.