Thanks to its Shadow RD+ design, the Shimano Deore RD-M5100-SGS rear derailleur delivers consistent MTB shifting performance over rough terrain. The low profile design avoids damage from rocks while Shimano's chain stabilizing technology reduces chain drop, achieving a quiet drivetrain in all gear positions at the same time.
The Top Normal rear derailleur for the Deore 1x11-speed drivetrain is designed to work perfectly with the large 11–51 teeth Shimano CS-M5100 cassette covering a wide gear range. The guide and tension pulley of the long SGS cage feature 13 teeth each.

Shadow RD+
Quiet drivetrain, less distraction. The Shadow RD+ system is lighter and more efficient than roller type chain devices. A rear derailleur stabilizer reduces chain slap and is a simple solution to prevent chain drop as well.

Speed: 11
Weight: 326 g
Cage length: Long SGS
Pulley teeth: 13T
Top sprocket max: 11T
Low sprocket minimum: 51T
Total capacity: 40T
Compatible chain: HG-X11