Rotor Cranks work by increasing the force required on the drive side crankarm which propels the non-drive crank are past the 12 o'clock point. The cyclist is now "permanently pushing" the cranks as there is no gap between when the legs take over push/recover duties, otherwise known as the dead spot.
Strengths: More power on climbs and flats. Less fatigue at the top of climbs
Weaknesses: heavier by about a pound. adds some noise
Bottom Line:
I had heard that Rotor cranks were good for square pedalers which I am and was very pleased when they were already on the Aero. Initially I felt they helped most on cimbs, on very steep grades at slow speeds you can feel the power stroke of the next leg beginning before the first has finished. Its a neat sensation. Today I actually caught a DF rider on the exact same hill that he has smoked me on before. However, I have also found that I can push higher gears on the flats. My standard 50 mile ride on my Strata I usually rode in just under 3 hours. With the Aero and Rotor cranks my first ride was 2:30 even for the 50.
