The Shimano Alivio RD-M3100-SGS is a 9 speed, long cage rear derailleur with a low profile SHIMANO SHADOW design.

What it's for

A replacement rear derailleur for 9 speed mountain and trekking bikes with double or triple cranks.

How it works

SHIMANO SHADOW RD: a low profile design that tucks the derailleur under the cassette so it does not hit the chainstay or trail obstacles.

Compatibility

• Speeds: 9
• Largest cog: up to 36T
• Total capacity: 45T
• How to check yours: total capacity is the difference between your largest and smallest cog plus the difference between your largest and smallest chainring

Setup and installation

• Cable tension is set with the barrel adjuster on the derailleur

Specs

• Model: RD-M3100-SGS
• Cage: long (SGS)
• Max low sprocket: 36T
• Total capacity: 45T
• Series: Alivio M3100