Sram X4 Rear Derailleur Long Cage BlackThe Sram X4 Rear Derailleur uses a Steel/Composite Cage with replaceable pulleys to demonstrate Sram’s 1:1 Actuation Ratio and Direct Route Technology to redefine the feeling of smooth shifting. The B-Knuckle is composed of the rugged 6061 Alloy. Weighs only 340 grams. Black in color.710845609671
