SRAM 55T TT chainrings are stamped from 7075 aluminium for low weight and excellent strength. The teeth are ramped and pinned for precision shifting, too. 130 mm bolt circle diameter. TT: Time Trial rings with added reinforcement for strength and special graphics on the outer ring (Yaw: X-GlideR versions compatible with 2012+ New-Red, hidden-arm crank clocking/timing and New-Red front derailleur/shifter). 7075-T6 aluminium with black hard anodized finish (2012+ replaces TGA Tungsten grey) and timed ramps/pins for optimized shifting performance. 55t rings recommended as only compatible with 42t inner.
Low weight and excellent strength
Made of 7075-T6 aluminium
Timed ramps/pins for optimized shifting performance
Black hard anodized finish
130 mm Bolt circle diameter