Crank Arm Power Meters for Road

Additional Crank Arm Power Meters for Road Info:

Brands

We carry road crank arm power meters from 4iiii Innovations and Stages Cycling.

Check Frame Compatibility

Before purchasing, you should confirm compatibly with your frame. On some bikes, there is not enough room between the left crank arm and the chainstay for the sensor to clear the frame. Therefore, you should make sure you have at least 10 mm of clearance for Stages and 4iiii PRECISION 2 power meters and 8 mm of clearance for 4iiii PRECISION 3 power meters. Also, make sure that you don’t have a bottom bracket mounted rear brake (used on some aero and TT bikes). Please refer to the image below.

Quick Product Comparison:

Price

While 4iiii and Stages make road crank arm power meters for different cranksets, in general 4iiii PRECISION 2 power meters are the lower cost option. On average, they are about 8-10% cheaper than Stages models. However, 4iiii’s newest PRECISION 3 models are priced slightly above the Stages models. On average, they are about 3% more. Once 4iiii discontinues the PRECISION 2, cost will favor Stages, ever-so-slightly.

Models

4iiii offers road crank arms for Shimano cranksets. Stages on the other hand, makes crank arms for Shimano, Campagnolo, FSA, Cannondale, SRAM, Easton and Specialized cranksets.

In addition, both companies make left crank arms (which are the power meters on this page), as well as complete cranksets that measure both left and right leg power. The complete cranksets can be found on our Cranksets page.

Installation

All these power meters install the same way. You simply remove your current, left-side crank arm power meter and replace it with your new, power-equipped version. Installation typically takes about 5-10 minutes for most models.

The one exception to this is the Stages Carbon for SRAM BB30 Power Meter, which also requires that you replace the spindle. Note that for Shimano models, you will also need a Shimano Crankarm Cap Tool (sold by us separately).

Power Measurement

All these left side crank arm road power meters measure power from the left leg and double the value in order to determine total power. This method of power calculation assumes that both legs are producing the same power.

ANT+/Bluetooth SMART

All of these power meters are dual ANT+ and Bluetooth SMART compatible.

Batteries

4iiii and Stages power meters use CR2032 batteries. 4iiii PRECISION 2 models offer 100 hours of battery life, while the PRECISION 3 gets a whopping 800 hours. Stages models get about 200 hours.

Weight

Crank arm power meters for road bikes are one of the lightest power meters you can buy. The 4iiii adds a mere 7.5-9 grams (based on the model) to your bike. The Stages adds 20 grams, which is still very light.