Rotor has just issued an update for its Power Meter cranks to resolve issues related to zero calibration and battery life. The units use a dual power meter to individually measure left and right leg power. They were introduced at Eurobike 2012 but didn’t start shipping until Spring 2013. Check out the tech details in this post.

Their sponsored riders found that batteries were getting drained very quickly. The culprit? Transportation. Having the bikes jostle and vibrate while in the team can or on a rack we’re keeping the system awake and trying to transmit, which killed the battery. (BTW, this problem isn’t limited to Rotor. If your own power meter battery seems to be running low frequently, this could be the cause) Now, an initial 1.5kg load must be applied to the crank to wake up the transmitter.

They also found that calibration set up wasn’t always accurate. This one sounds like mostly user error, like trying to calibrate on the move, so it now requires a zero RPM state to be zero’d out.

Lastly, they’ve made software updates easier with an update to the PC software.

Full PR and links below…

PRESS RELEASE: In its first two years since hitting the market, ROTOR Power became the power meter of choice for many elite-level teams and athletes, such as Lampre-Merida, Caja Rural (road); Sunweb (cyclocross); and Frederik Van Lierde and Timo Bracht (triathlon). However, like any sophisticated advancement, Power faced some difficulties.

“The pros were putting the product to hard use and the most recurrent challenges they experienced had to do with installation issues and elevated battery consumption,” explained Julio Madrigal, sponsorship manager for ROTOR Bike Components. “The racers demanded that we resolve them.”

Together in collaboration with its teams and athletes, ROTOR has released new features intended to make Power even more sophisticated, accurate and reliable. New SW 0.900 firmware and new user software, as well as videos to demonstrate the various features of Power, have closed the gaps that would potentially prove challenging for consumers.

“The athletes were finding that the battery would get drained during non-pedaling instances, like bike transportation and handling,” said David Martínez, product engineer for ROTOR. “To solve the issue, you now have to apply an initial load of 1.5 kg. in order to activate the crank.”

ROTOR’s new SW 0.900 firmware also resolved a problem where users reported faulty data readings and disconnections, which originated from incorrect crankset calibration. Now calibration is only possible if cadence = 0 RPM. Another feature of SW 0.900 is a function to reset the processing chip in rare cases where malfunctions were occurring with certain wireless processing devices.

The ROTOR Power User Software 1.4 introduces the new RX Level function to increase security for wireless updates. The RX-radiofrequency signal shows how effectively the cranks communicate with the computer in order to avoid failures during the wireless updating process. Equally important is an improved function for updating data between the crank and software.

Tested and developed by the professionals, the new SW 0.900 firmware and software are now available to consumers at


  1. alvis on

    (BTW, this problem isn’t limited to Rotor. If your own power meter battery seems to be running low frequently, this could be the cause)

    Only if your sensor trigger uses an accelerometer. The other problem with accuracy when actually riding is the road noise, probably another reason they were getting faulty data and dropouts. Magnets and a reed switch may sound old fashioned but the tech is hard to beat in this kind of application.

    And why oh why do power meters need calibrated every five minutes? No other decent measuring device requires this level of user maintenance. Cyclists tolerance for substandard engineering is way too high.

  2. Andrew Coggan on

    The “road noise” problem seems to have been fixed via a previous firmware update (SW 0.800, I think). At least, I have not encountered any of the data artifacts that earlier adopters initially reported.


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