A high performance double chainset from the classic atb group using the most advanced 10 speed dyna sys chainringsforged hollowtech ii aluminium cranks offer unrivalled strength to weight ratiolightweight construction with external super smooth bottom bracket bearings for efficient usealuminium double anodized outer chainring with plated inner ring for excellent rigidity and durabilityoptimised q factor for double chainsethg x chainring with patented spike pins give smooth and fast gear shifts u