If you were particularly eagle-eyed in your examination of Mark Renshaw’s Cervelo S5, your attention might have been drawn to a little “2” on the right-hand crank, which certainly wasn’t there on the Rotor INpower power meter that the Dimension Data and Lampre-Merida were using last year.
That little digit denotes that this is a prototype version of the second generation of the Spanish company’s INpower power meter, an axle-based system that measures power from within the bottom bracket. We’ve been in contact with Rotor for the details on the new version.
While the first generation of INpower was a single-sided system (meaning that it measures the power output of your left leg, before doubling that value to give an estimate of your total power output for both legs, the second generation, which will be called Rotor 2INpower, will be a dual-sided system, measuring both legs independently.
From the battery compartment that is visible on the right crank arm, we’d expect that this system will simply take the existing INpower system and give it some extra strain gauges for the right side of the crankset. However, Rotor isn’t willing to give any further details at this time, beyond saying that 2INpower will “share some of the characteristics” of the existing system.
Look out for a full product announcement in the spring.