To reduce speed robbing friction the RED rear derailleur uses new AeroGlide pulleys. The AeroGlide pulleys have an optimized tooth profile to work best with SRAM''s PC-1091R chain although other 10-speed chains will work just fine. These pulleys are the key to this derailleurs quietness. To insure that they roll smooth SRAM uses Black-Box Ceramic Bearings in both the upper and lower pulleys.

Features
Exact Actuation cable pull ratio for super-precise shifting in conjunction with ZeroLoss shifters
Carbon fiber cage and inner link, titanium hardware, and AeroGlide ceramic bearing pulleys
Polished aluminum outer links with integrated, spring-fixed barrel adjuster
Short cage has extended B-Knuckle for improved clearance with 28t cassettes

Specifications
Speed: 11 speed
Cage: short
Min/Max: short cage - 11/28T; medium cage - 11/32T
Color: carbon/grey/black

Mfr Claimed Weight
short cage - 145g; medium cage - 165g