Single-ring drivetrain simplifies functionality and reduces weight 48 and 50t variants feature direct mount aero chainrings for better aerodynamics Non-aero chainrings can be installed with a single tool, making gearing changes a breeze SRAM X-SYNC™ wide-tooth, narrow-tooth chainring technology provides maximum chain control Laser-etched chainring finish is more durable DUB™ bottom bracket adds durability and simplicity Can be upgraded to a power meter SRAM Model ID: FC-RED-1-D1