Innovative modular structure: the ALDHU 24 Crankarms from ROTOR The ALDHU incorporates OCP Mount technology, which enables the rider to fine-tune the orientation of ROTOR's oval Q rings. The ALDHU's proprietary, patent-pending design is based on the modularity of each crankset component. The new model name comes directly from our racing heritage. It is an abbreviation of Alpe d'Huez to commemorate ROTOR's first iconic victory at the Tour de France with Carlos Sastre. Technologies TDS ROTOR's CNC-machined cranks feature our Trinity Drilling System, which is a process that drills three full-depth holes along the axis of the crank. OCP Optimum Chainring Position (OCP) represents the different setup positions that ROTOR Q rings offer to fit a rider's distinct pedaling style. Q rings feature up to 5 OCP's, with OCP 3 as an intermediate starting point, all to optimize your pedaling style. You can determine your OCP if you know your Optimum Chainring Angle (OCA), which can be found by conducting a TORQUE 360 pedal analysis via ROTOR's 2INpower and INpower User Software.