Shimano's Ultegra 6800 chainrings provide confidence-inspiring shifting and category-defining speed. Cold-forged aluminum comprises these super-stiff, hollow outer rings, and Shimano's unique system of ramps and pins means lightning fast shifts are at your command. - Bolt circle diameter: 4-bolt 110mm asymmetric - 50T pairs with 34T inner ring - 52T pairs with 36T inner ring - 53T pairs with 39T inner ring Inner rings sold separately