A high performance chainset from the classic atb group offering the most advanced featuresforged hollowtech ii aluminium cranks offer unrivalled strength to weight ratiolightweight construction with external super smooth bottom bracket bearings for efficient usedrilled steel and carbon composite construction middle ring combined with a thicker aluminium double anodized 44 tooth and plated aluminium 22 tooth ring for excellent rigidity and durabilitysg x chainringsdelivering a smooth precise shif