The superlight and stiff carbon rims have an asymmetrical design shaped by exhaustive wind-tunnel testing and data. The all-new R3-C40 aero hub with ceramic bearings reduces friction by up to 30 percent over the previous generation. And the 22.4mm wide hookless rims create a seamless integration between the rim and tubeless tire for improved rolling resistance, increased sidewall support, and better cornering grip. It all adds up to best-inclass aerodynamics, unbeatable efficiency, and total control in all conditions.