Reviewed - Axle based Power Meters

To self fit these Axle based power meters you must be confident at removing your crankset from your bottom bracket (or pay your LBS to do it for you). These units are very robust as the power sensors are contained within the axle housed inside Bottom Bracket assembly. This makes them ideal for MTB and XC riders.

The power is usually measured only from one side. They provide averaged total power by multiplying the power measured in one leg (like the Crank Arm power meters). The Rotor InPower devices are very popular as they use regular AA batteries giving 300 hours+. They have been designed with VERY EASY battery change in mind.

NOTE > there are a few units like the Rotor 2INPower that have TWO sets of sensors, one in the BB/axle (left leg) and the other in the crankarm (right leg). These bi-lateral power meters provide TRUE left & right power balance. The total power output is also a TRUE value as it's measured from both legs, not estimated. If power phase and power balance are parameters that interest you please consider some of these dual sided power meters.


  • This power meter is compatible with ANT+ devices
    This power meter measures power from the LEFT side
    Medium priced option
    Moderate skills required - may require tools & assistance

    Rotor INPower 3D+ single

    A popular design for cyclists who want their power metering solution hidden away. The Rotor INPower 3D+ system has it's strain gauges inside the bottom bracket axle keeping them away from harm. Specifically designed for accurate power metering with Q-Rings. This is just the LEFT side crank arm. You must already have a Rotor crankset on your bike to use this power meter ...

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  • This power meter is compatible with ANT+ devices
    This power meter measures power from the LEFT side
    Medium priced option
    Moderate skills required - may require tools & assistance

    Rotor INPower 3D+ double

    A sophisticated power metering system with all the sensitive electronics housed inside the axle unit. The Rotor INPower 3D extracts power from the left leg only to give an estimated TOTAL power. Specifically designed for accurate power measurement with Q-Ring chainrings. Fans of this power meter are attracted to it's robust design and the 300 hour battery life from a single AA battery. This double model comes as a full crankset kit ...

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  • This power meter is compatible with ANT+ devices
    This power meter measures power from BOTH legs
    Most expensive option
    Moderate skills required - may require tools & assistance

    Rotor 2INPower System

    A beautiful piece of engineering. The Rotor 2INPower Dual sided power metering system has two independent strain gauges. One, in the right crank arm and the other in the bottom bracket axle (left leg power). Through this innovative design the Rotor 2INPower Dual provides accurate LEFT and RIGHT power balance as well as a true TOTAL power output figure.

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