SRAM XO1 12s ChainIt might look normal from the outside, but the engineering inside this incredible chain design makes possible a gear range previously found only in 2 chainring drivetrains. And it's also the biggest contributor to the Eagle drivetrain's ultra smooth, precise, durable and quiet performance. The Eagle chain's links have a smooth radius, with no sharp edges or chamfers, which yield a significant reduction in noise, friction and wear on chainrings and