Key Features:Lightweight 2-piece design 11-speed chainset,2-piece design forged and anodised aluminium crank arms keep weight low,The chainring teeth have been developed to work in conjunction with HG-X 11-speed chains for increased contact to provide greater efficiency and improved power transfer,Bottom bracket bearings are spaced wide apart, enabling the use of larger bearings and an increased axle diameter,Chainring spacing has been optimized for use with 135 / 142 mm rear axle spacing and short chainstays,Can be used with Shimano external or press-fit bottom brackets,The system allows for easier installation, adjustment, and maintenance,Lightweight anodised SG-X aluminium chainrings for smooth and precise shifting.