SRAM X-Sync 2 oval mountain bike chainring Oval chainrings smooth out the power curve and increase pedalling efficiency - most noticeable on technical terrain SRAM direct mount Eagle Technology creates the smoothest, quietest, longest lasting and most efficient drivetrains SRAM have ever made. X-SYNC 2 chainring design increases chain retention, wear life, and reduces friction and noise. Designed to be used with Eagle chains Aluminium