Trail riders on a 1x12 Shimano mountain bike drivetrain who ride rough ground and want a quiet, settled chain.
The Shimano SLX RD-M7100-SGS is a long-cage rear derailleur for 1x12-speed mountain bike drivetrains. It takes cassettes from 10T up to 51T, has a 41T total capacity, and weighs 313 g by Shimano's own figure.
SHIMANO SHADOW RD+ keeps the chain stable on rough ground, and Shimano added a bumper on the pulley cage that absorbs chain impact on aggressive terrain. Derailleur and chain tension are lower in the lowest gears, and the bigger 13T pulleys help efficiency and chain control.
Bumper on the pulley cage
Absorbs chain impact on aggressive terrain, according to Shimano.
SHADOW RD+ stabiliser
Reduces chain slap for a quiet drivetrain in every gear.
Lower tension in low gear
Shimano reduced the derailleur and chain tension in the lowest gear positions.
13T pulleys
Larger pulleys for better efficiency and chain control.
Drivetrain fit
Construction
SHIMANO SHADOW RD+
A rear derailleur stabiliser that reduces chain slap and gives a simple answer to chain drop. Shimano says it is lighter and more efficient than a roller-type chain device.
HYPERGLIDE+
Shimano's shifting technology for fast, shockless shifts, matched to its wide range 12-speed 10 to 51T drivetrain.
Great for
Maybe not for
Long cage (SGS): largest sprocket 51T, smallest 10T, total capacity 41T, single chainring only. Use it with an HG 12-speed chain and a 12-speed cassette. It fits conventional direct-attachment and UDH derailleur hangers.
Use the lever switch properly
Shimano's manual says to move the lever switch to OFF before you take the rear wheel out, and it recommends leaving the switch ON while riding to reduce chain slap and help keep the chain on the sprockets. Check the plate unit cover and its cap are fitted before every ride, and do not take the derailleur apart or modify it, as you may fall and be seriously injured. Keep rust cleaners away from the chain, because alkali or acid based solvents can make a chain break.
