The strong, silent type. The Shimano Alivio RD-M4000 SGS rear derailleur is designed for aggressive riding. With its super low profile and single-tension construction, it does not hit the chainstay in rough riding conditions. It's smooth and quiet, featuring Shadow Rd technology for less trouble.
Alivio RD-M4000 7/8/9 Speed Rear Derailleur
Features:Wide link design increases durability and precise shifting.