The 10-speed Dura-Ace crankset is doubtlessly the signature component of the 10-speed gruppo. From a visual standpoint, it screams for attention. But from a technical perspective it's likely the single most advanced component in the gruppo. It uses a two-piece design to maximize its lightness and to provide unmatched stiffness. A huge hollow cro-moly spindle is press-fitted into the driveside of the Hollowtech II crankarm.