The engineers at Rotor Bike Components developed their original Rotor Crank to maximize the efficiency of your pedal stroke by prolonging the power zone and minimizing dead spots. With these ovalized Road Outer Q-Rings, you can have the majority of the benefit of the Rotor crankset, but you can use the crank of your choice (Shimano, Campy, SRAM, et al). And with redesigned shift pins and ramping, Q-Rings shift without hesitation. Any assumptions that this is rehashed Biopace are wrong. To the contrary, Rotor Road Outer Q-Rings will help you produce more power and reduce fatigue. They capitalize on the strongest part of your pedal stroke and minimize the negative effects of dead spots. The Q-Rings have a subtle oval shape and, with multiple mounting holes, can be 'clocked' to maximize the effects for your biomechanics, pedaling style, and bike geometry. The Q-Ring's oval shaping smoothes the pedal stroke through the dead spots and takes advantage of your power potential at the optimum time -- in the power zone. The multiple mounting hole system is called OCP (Optimum Chainring Positioning) and it allows each rider to maximize the benefit of the Q-Rings. The long axis of the oval chainring should be vertically aligned in the power zone when the crankarms are at or just below horizontal. This position gives the rider maximum leverage, and therefore maximum torque transmission to the rear wheel. Inversely, the short axis of the chainring is aligned so that it nears the vertical when the crankarms are also close to vertical.