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RotorINPower Direct Mount Power Meter Crank Arms - MTB


Item # RTR003F

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  • Black, 170mm ($750.00)
  • Black, 175mm ($750.00)
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Item # RTR003F

INPower Direct Mount Power Meter Crank Arms

More and more cyclists are using the powerful ride metric of wattage while training, including mountain bikers, and with the INPower Direct Mount Power Meter Crank Arms from Rotor, you too can get on board and start training with purchase. Whether you're an XC junkie looking to raise your FTP and crush the competition or an enduro racer trying to pace yourself on the transfers between the stages, a powermeter can keep you in check and open up a world of new training options. If you have a coach or you're your own, the ability to record, parse, and analyze pedal stroke data can help you identify strengths and weaknesses and help you become a better rider.

Instead of the dual-leg, eight-gauge approach of the 2INpower model, the INpower meter uses four gauges to measure power and pedal stroke data coming through the left crank arm only. The strain gauges themselves live in the spindle. This provides more protection against the elements (be they rain, snow, or trail furniture encountered during the occasional user error), and it also helps to tidy up the crank's silhouette by eliminating bulbous protrusions at the crank arm/chainring interface—of course, the grooved crank arms and (should you run them) Rotor's iconoclastic chainrings will still stand out.

As with other power meter cranksets, the INpower's four strain gauges are all spindle-bound and it's equipped with an accelerometer to read cadence; unlike other meters, Rotor's design measures cadence over 500 times per pedal stroke. While the benefits of mapping minute changes in cadence over each leg's power production are immediately obvious to any data obsessive, the potential is magnified exponentially when paired with Rotor's direct mount Q-Ring system. It helps you chart the most efficient direct mount Q-Ring orientation possible to capitalize on the strengths of your pedal stroke while mitigating the weaknesses. The crank arms work just fine with traditional round rings, but adding Rotor's direct mount Q-Rings takes full advantage of the system's potential.

The INpower transmits data via ANT+ Smart protocols, so chances are good that it's already compatible with whatever head unit you're running; however, it's a bit more limited on the bottom bracket front. The INpower Direct Mount Power Meter Crank Arms have a 30mm spindle, so it may take some adapting to adapt it to your shell, but it's compatible with English and Italian threaded, BB86, BBRight, BB386EVO, and—of course—BB30 and PF30 bottom bracket shells. The unit's 300-hour ride time relies on one AA battery, so re-upping is never an issue. Rotor also provides a seamless data upload and management interface by partnering with TrainingPeaks.

The crank arms themselves are the product of Rotor's Trinity Drilling System (TDS), a method of hollowing out the cranks, which reduces weight and maximizes stiffness. Unlike traditional hollow crankset design, TDS involves drilling three channels from the pedal to the spindle. While these holes remove excess material, they also leave behind two thin walls, making them stiffer than the design of a single hollow chamber. The TDS creates a maximum strength-to-weight ratio, and the arms are constructed using 6082 and 7075 aluminum alloy.

  • Take the power to the trail with Rotor's mountain crank
  • Four strain gauges extrapolate total output from left crank arm
  • Charts cadence with an internal accelerometer
  • Electronics housed in the spindle to protect from elements
  • Replaceable AA battery ensures a re-upping isn't a chore
  • Lightweight, stiff alloy construction proven on the biggest stage
  • Pair with direct mount Q-rings for maximum training metrics
  • Partnership with TrainingPeaks makes for seamless data management

Tech Specs
Arm Material6082, 7075 aluminum alloy
Arm Length170, 175mm
Bolt Circle DiameterRotor Direct Mount
BB TypeBSA, BB30, BB30a, BB89, BB92, PF30
Q Factor169mm
Recommended Usemountain biking
Manufacturer Warranty1 year

Actual Weight

Black, 170mm
Black, 175mm

Claimed Weight

Claimed weights are provided by the vendor.

Have questions? Chat with a Gearhead

[170mm] 1lb 3.2oz

Actual weights are measured in-house by the Competitive Cyclist team.

Have questions? Chat with a Gearhead

What do you think about this product?


>Rating: 5

Reliable and Consistant

I've put it through the wringer

This power meter is awesome. It is super durable, reliable, consistent, and easy to use. The power meter quickly connects to any computer and allows you to calibrate. Then you're ready to ride. You do not have to calibrate it every ride, but if there is a major fluctuation in temperature at the start of your ride, then it is not a bad idea. The chain rings can be easily swapped. The crank arms are strong and stiff once you're laying down the power. A must have to bump your training up a notch.


is compatible gxp [PF-92]