The Rotor ALDHU Carbon Crank Arms are the focal point of Rotors first carbon crankset. The set is incredibly lightweight, dropping about 100 grams compared to the aluminum version. Both vertical and horizontal stiffness are significantly increased as well. The carbon ALDHU features the same modular design as previous models for use with any Rotor 1x or 2x direct moutn chainrings. These arms are made for use with 30mm axles, offering an interface that makes assembly extremely easy while maintaining a firm fit. Rotor found that power is often lost as a result of axle torsion under pedaling force. TO fix this problem, they created Twin Leg technology which provides a more balanced approach, reducing power losses when force is exerted on the left pedal. With the ALDHU Carbon Crank Arms, all of your effort will be directly translated into speed and power.