2-piece design forged & 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 & enhanced power transfer. The bottom bracket bearings are spaced wide apart, enabling the use of larger bearings & an increased axle diameter. The system allows for easier installation, adjustment, & maintenance. Lightweight anodised SG-X aluminium chainrings for smooth & precise shifting.