On Bicycles, and.... what else is there?

When you think about power meters what professional team comes to mind? Only one... Indeed, there's a web site devoted to photos of Chris Froome looking at stems . Staring at his SRM display, many have claimed. Sucking the humanity of out racing by reducing it to pre-programmed efforts determined by power analysis? Hardly, obviously, but traditionalists always oppose change. He even does it in Pro Cycling Manager , a video game: So it's a major change in the world as we know it when it's leaked that for 2014, Sky is discarding their trusty SRMs for Stages power meters: Stages measures power on only the left leg, assuming the right leg is the same. This, not surprisingly, results in errors. I looked at Stages power data in this blog post . For example, comparing Stages power / 2 to Vector left-leg power is a good match, according to DC Rainmaker's data: But compare it to the Vector right leg data, and things get uglier: It typically takes two legs...

An interesting issue came up in the Wattage list , and that is that the Cinqo (and presumibly the SRM ) calculate power under the assumption that the pedal cadence is uniform throughout the pedal stroke. This is an interesting assumption, worth investigating, in light of my recent discussion of Metrigear hitting its 1.5% power target. In my discussion on Metrigear, there were two principal limiting factors to accuracy: one was nailing down the pedal orientation, the other was getting the pedal rotation rate correct. For the orientation, the system was getting close after only 20 seconds of my simulation of highly variable cadence, a worst-case scenario. Results I didn't show were that if I simulate longer periods, the system continues to improve on its orientation determination, and can nail that down to a fraction of a degree. That's good enough to separate out the "propulsive" component of force. On the other hand, the primary challenge remained the determ...