IAV Power Technology

If you follow us or read any of our articles, you’ll know that we are big fans of Favero’s power meter pedals. The Favero Assiomas power meters are accurate, reliable, easy to install and are compatibility with any bike. In addition, they are the most affordable power meter pedals available. For example, both the Favero Assioma DUO and Favero Assioma PRO MX-2 sell for $759. This is less than any other dual-sided road or MTB pedal. Favero’s single-sided pedals are also priced below the competition. Well…if this isn’t enough, these power meter pedals also feature Favero’s IAV Power Technology which makes them one of the most accurate power meters available.

 

Most PMs Assume Constant Velocity (or Average Angular Velocity)

As we discuss in our article on Power Meters and Oval Chainrings, most power meters make a pretty key assumption regarding your pedaling speed. That is, they assume that your pedaling velocity is constant. That is not the same as cadence. Cadence measures how many times you turn the cranks within a 60 second span. Rather, we’re talking about the speed at which you turn the pedals during each pedal revolution. Again, most power meters assume your speed during each pedal stroke is constant – also called average angular velocity or AAV. Well some riders have pedaling styles where their velocity can vary at different points in the pedal stroke. If you’re one of these people and your power meter uses AAV, your power data can be skewed.

Oval chainrings can really cause this problem. Due to the very nature of what oval rings intend to accomplish (speed up your pedal stroke during the dead spot and slow it down during your power phase), they can lead to rather meaningful inconsistencies in your pedal stroke revolution. Most studies say oval rings can skew your power data anywhere from 1.0% to 4.0% (upwards). Favero cites research that concludes errors caused by power meters that use AVV can reach 4.5%.

The Fix: Actual Instantaneous Angular Velocity (IAV Power Technology)

Well IAV Power Technology sets out to fix this issue. Using proprietary software and an integrated three-axis gyroscope, the Assioma can measure actual instantaneous angular velocity. Unlike AAV, IAV takes into account your true pedaling speed within each pedal stroke. It can do this regardless of your unique pedaling style or the shape of your chainrings. But the cool part is, not only does IAV fix the issue of inconsistent pedal stroke revolutions, but in doing so, it also improves the accuracy of the Assioma from +/-2.0% to +/-1.0%. That’s not bad for a free firmware upgrade!