The Best Dual-Sided Power Meters

A dual-sided power meter puts a sensor on each leg and adds the two numbers together. A single-sided meter measures one leg and doubles it. That is the entire difference, and everything worth saying about this category follows from one question: what do you actually do with the second number?

The answer for most riders is “nothing, yet” — and the reason to buy dual-sided anyway has changed. It used to be that two sensors cost roughly double. It no longer does. The cheapest dual-sided pedal on this page now undercuts several single-sided units we recommend, which turns a question about data into a question about price brackets. If you can have both legs measured for the money you were going to spend on one, there is no argument left to have.

How we ranked these

Criteria first, picks second. We do not do our own instrumented accuracy testing, so nothing on this page is ranked on a number we generated. It is ranked on four things we can check.

1. A published tolerance, from the manufacturer. Favero, Garmin and Magene all publish a figure for every unit here. Five of the six claim ±1%; the Magene PES P505 claims ±1.5%. Where a manufacturer does not publish a tolerance, we treat it as unknown rather than assuming the category norm — which is why some units on our main power meter ranking sit lower than their marketing suggests.

2. The weight of independent evidence behind that claim. A published ±1% is a claim, not a result. The Assioma Duo has been measured against trainers, cranks and other pedals by more testers over more years than anything else in the category. The Magene P715 S has a thinner and noisier record. Both claim ±1%. Those two facts are not equal, and we rank on the second one as well as the first.

3. Battery life, as published. This is the most under-weighted specification in the category, and the spread here is enormous: about 50 hours for the Assioma Duo, 90 for the Garmin Rally 210, 120 for the Magene P715 S and up to 160 for the Assioma Pro RS-2. For a rider doing four structured indoor sessions a week, that is the difference between charging monthly and charging twice a season. Our power meter battery life guide lists every published figure side by side.

4. Whether it fits the shoes you already own. Cleat system is the single most common reason a power meter purchase goes wrong. Look Keo, Shimano SPD-SL and two-bolt SPD are not interchangeable, and a pedal that needs new shoes is more expensive than its price tag. Power meter pedals and cleat compatibility maps the whole field before the specification sheet matters.

What the second sensor actually buys you

Three things, and only one of them is used by most riders who pay for it.

A total that is measured rather than estimated. This is the real one. A single-sided meter reports your left leg times two. If you are 50/50, that is correct. If you are 48/52, it reads about 4% low — and the figure drifts with fatigue, cadence, gradient and whether you are out of the saddle. A dual-sided meter has no such offset, which is why it is the only sensible choice when your numbers have to travel: to a coach, into a race category, or across to a different device.

A balance figure. Useful in exactly two situations — returning from an injury or a surgery on one leg, and chasing down a bike fit problem that only shows up under load. Outside those, most riders look at it for a month and then never again. It is a diagnostic, not a training metric, and nobody has ever got faster by staring at it.

The advanced pedaling metrics. Torque effectiveness, pedaling smoothness, power phase, platform center offset. These are genuinely interesting and almost entirely unactionable without a coach who asks for them. Do not let them decide the purchase.

When single-sided is still the right call

If you ride indoors, train to your own numbers, and compare this week to last week, a single-sided meter is internally consistent and the doubling error is invisible to you — because it is the same error every time. That is the whole case for the category, and we make it properly in best single-sided power meters and single vs dual-sided power meters.

There is also a budget argument that still holds in one direction. If your choice is between a single-sided pedal from a maker with a long record and a dual-sided pedal from one without, buy the record. Two sensors measuring to an unproven standard are not better than one sensor measuring to a proven one.

And if you already own a current smart trainer, be honest about what you are solving. The trainer measures power indoors already. A pedal meter earns its money by following you outdoors and acting as the reference your trainer gets checked against — the argument we run in smart trainer vs power meter. If you never ride outside, that argument is weak and the money is better spent on the trainer itself.

Pedals or cranks?

Five of the six picks here are pedals, and that is not an accident: pedals are the only format where dual-sided is both easy and portable. Two sensing pedals move between bikes with a 15 mm wrench, and you can be riding power on a second bike in five minutes.

Dual-sided crank measurement is harder and rarer. A left-arm meter can only ever measure one leg, so a crank-based dual-sided meter means either a complete crankset with gauges on both arms (the Magene PES P505 here) or a spider meter that measures total power without splitting it. The crankset route is cheaper and completely protected from curbs and bike racks; it just cannot move, and it pulls your bottom bracket into the decision. Power meter pedals vs cranks is the full version of that argument.

Before you order

Check the cleat system against your shoes, not against the picture. Look Keo and Shimano SPD-SL look similar in a product shot and are not compatible.

Check whether cleats are included. Favero supplies compatible cleats with the Duo and the Pro RS-2. Magene does not supply them with the P715 S.

Check crank clearance and Favero's fitting limits. Favero publishes restrictions — no pedal extenders, no shorteners, a crank thread-length ceiling. They exist for a reason and they are easy to read before you buy and expensive to discover afterwards.

Plan the first calibration. Every meter on this page wants a zero offset after fitting, and after any big temperature change. Our calibration guide covers it in about two minutes, and connecting a power meter to Zwift covers the part that goes wrong most often on a first indoor ride.