The shimano rs500 4636 10 speed double chainset is a lightweight 2 piece design 11 speed chainset the 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 the bottom bracket bearings are spaced wide apart enabling the use of larger bearings and an increased axle diameter which means these cranks can be use