Accurate is an understatement.
The Rotor 2INPower Powermeter MTB Crank Arms features two sets of strain gauges measuring power independently in each leg with the high accuracy level of +/- one percent. Power information is then wirelessly transmitted via Bluetooth Smart or ANT+ to your preferred head unit or Rotor's smartphone app available for iPhone and Android devices. For these mountain bike-specific 2INPower Powermeter Crank Arms, you'll find the electronics and battery are neatly tucked inside the axle where they're safe from moisture ingress and harsh abuse out on the trail.
While the electronics are all spindle-bound, there's four strain gauges in the axle for left leg measurement and four in the right crank arm for the right leg measurement. Rotor claims this design negates the need to re-calibrate settings due to drastic temperature swings. And seeing they're laid out in opposition, the eight gauges work as internal correctives to each other to provide more points of input, help the system reduce drift, and eliminate the need to constantly zero by establishing a more comprehensive body of aggregate data.
As with other power meter cranksets, the 2INpower is 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 Q-Ring system. It helps you chart the most efficient 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 Q-Rings takes full advantage of the system's potential.
The 2INPower Powermeter MTB Crank works with Rotor's 30-millimeter Universal Bottom Bracket (UBB) design, making it compatible with nearly all standard frames on the market with the use of spacers (the only exception is it's not compatible with BB90). For chainring choices, you must run them with Rotor's direct-mount mountain bike rings, either their NoQ rings or Q-rings with a 110-millimeter bolt circle diameter, ranging from 26 to 34-tooth sizes for customizing your gearing range. The battery is fully contained and rechargeable via a magnetic connection in the proximal end of the crank arm. While it's recharging, Rotor provides a seamless data upload and management interface by partnering with TrainingPeaks.
- Mountain bike powermeter cranks with +/-1% accuracy
- Eight strain gauges increase accuracy, reduce need to zero
- Independently measures left and right leg power output
- Charts cadence information 500 times per pedal stroke
- Electronics housed in spindle to keep out the elements
- Compatible with Rotor's direct-mount NoQ and Q-rings
- Charts maximum pedaling efficiency with Rotor Q-Rings
- Bluetooth Smart and ANT+ for head units and smartphones