Power meter pedals are one of the most popular types of power meters. The big advantage to pedals is they are compatible with any bike. You don’t have to worry about compatibility issues with your drivetrain as you do with a crank arm, spider or crankset power meter. In addition, power meter pedals are very easy to install. Most of them install just like a normal road pedal and can be set-up in a few minutes. This also means they can be quickly and easily moved between bikes. As an added bonus, if you purchase dual-sided pedals, you will be able to measure each leg’s power individually. This is referred to as independent left/right power analysis.
Single-Sided vs. Dual-Sided
You can purchase a power meter pedal as a single-sided unit, or dual-sided. With both options, you get both a left and right pedal, however with a single-sided unit, only one pedal has a power sensor in it (typically the left pedal). It works by taking your left leg power and doubling it to approximate your total power. With a dual-sided unit, there is a power sensor in each pedal. These versions are more expensive, but they are also more accurate as they are able to measure the actual power that is being generated by each leg. In addition, as previously mentioned, they are able to measure independent left/right power. Single-sided units start around $459 and dual-sided units start around $719.
In terms of accuracy, they are right on par with other direct force (drivetrain located) power meters and are stated to be accurate to +/- 1.0-1.5%.
Please note you must use the cleat system that is specific to your power meter. Pedal-based power meters support both Shimano SPD-SL (Garmin) as well as LOOK Keo cleats (Favero, Garmin and SRM/LOOK). (Speedplay pedals remain unsupported by existing pedal-based power meter offerings.)