There is no better way to train for long gravel and dirt rides than with long gravel and dirt rides, and there is no better tool to assure you’re training efficiently and properly than a power meter. Power meters have long been used on-road, but thankfully we are seeing more and more options for the off-road crowd. Stages Cycling provides simple, robust, and accurate power meters that are perfect for wet, dirty, and rough environments.
Of course Stages markets meters for roadies, and you’ll see them on Team Sky’s bikes, but I believe Stages makes the perfect meter for off-road conditions. The housing is tiny. Not only is it better protected by the crank arm, it also can fit bikes with flared chain stays. Stages lists the housing height at 10 mm (0.39”). This packaging not only houses the strain-gauges for the power measurements but also an accelerometer for crank position allowing cadence output from the meter without the need for a separate magnet or sensor. The housing is made from PC-ABS plastic and is waterproof. This is not only a plus for muddy rides and stream crossings but gives peace-of-mind when you’re hosing down a dirty bike after the ride.
The Stages power meter uses a crank arm based power measurement that collects the power from the non-drive side crank arm. The left-side only measurement keeps the complexity and the price down. Yes, left-only means that power numbers are based on the left leg and you cannot see left-right balance and other pedaling dynamics, but it also means you have less dangly bits on the bike that can potentially fail or get smashed. The Stages Power meter is one of the cheapest on the market with the Ultegra meter reviewed here retailing for $580.
Initial pre-ride calibration of the meter is ultra-simple. To calibrate you simply spin the cranks to wake up the meter, set the left arm to the 6 o’clock position, and follow your computer’s screen prompts for calibration. On the Garmin 1000 this requires you to select sensors then select the power meter from your list of sensors, click calibrate then click calibrate again. After about 5-15 seconds the meter is calibrated and ready to roll. Stages employs Active Temperature Compensation to allow the meter to compensate for changing temperatures during a ride, so after the initial calibration, you don’t have to worry about recalibrating mid-ride should the temperature change drastically (see E on Neil’s ATR recap).
The Stages meter offers Bluetooth and ANT+ connectivity. In addition, there is an app that communicates to the meter using either of those. I tested the app with Bluetooth. If your computer’s calibration process seems a bit tricky, you can calibrate the meter in the app instead. There is a real-time display of power and cadence. There is also a “High Speed” function which records force and torque and can output that file as a *.CSV. I attempted to ride and gather data for analysis and plotting, but the app failed to collect the data on both attempts. I did gather some data while inside but overall found this feature of little to no use. The most useful features of the app are wireless firmware updates for the meter and a display of the current battery level. With regards to battery life, Stages claims 200+ hours from a single CR2032, and based on my usage so far and the indicated remaining life, it seems to be well on the plus side of that 200+.
Stages has a long list of supported crank arms for both road and off-road. This list seems to be expanding often. See http://stagescycling.com/us/products/ for the meters currently offered.
As a mechanical engineer who runs and analyzes dynamic tests for my day-job, I would love to be able to see a bit more data export options from these units, especially with regards the power profile across the pedal-stroke. But this single arm unit holds the price down by keeping it simple. There is an intrinsic value in simplicity. And the Stages Cycling power meter is simple to calibrate, simple to use, and very simple to recommend.