Shimano 105 cx50 double 10sp chainset black the hollowtech ii 10 speed cx50 cyclo cross chainset is the perfect choice for enthusiast riders please note bottom bracket is not included 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 evolved to increase