Shimano 105 cx50 double 10sp chainset silverthe hollowtech ii 10 speed cx50 offers an ideal balance of light weight and stiffness making it the perfect choice for both enthusiast and competitive riders features alloy chainrings are both rigid and lightweight the chainring teeth have been developed to work in conjunction with the 10 speed directional hg road chains for increased contact to provide greater efficiency and improved power transfer industry leading cold forged crank arms have been e