Campagnolo Ultra-Torque carbon crankset riders have been impatiently waiting for the Stages Power Meter folks to offer their popular left crank arm power meter. Now, after a few years of development and testing, Chorus 11 Ultra-Torque Stages left arms are available: a 20 gram power meter unit bonded to a new genuine Campy carbon crankarm. Stages power meters are ANT+ and Bluetooth dual channel compatible to work with a host of head units and devices at the present and into the future. You can use your Stages Power Meter with almost any current smartphone via Bluetooth Smart with two-way interaction, and simultaneously be connected to your ANT+ compatible computer/GPS head unit for in-ride data and collection. The StagesPOWER App offers several key features and functions, is easy to use and is free for Stages Power Meter owners. Stages offers tools that allow you to improve performance, and maintain balance in your training process.

Why measure power at all? Power gives you a clear representation of effort and output that is consistent. Knowledge of power data allows you to exploit your strengths, improve your weaknesses, and plan crucial recovery. It is true that there are cyclists, most at the highest levels of the sport, who can truly benefit from accurate individual leg and spin cycle measurement. Cyclists overcoming injuries may also find this highly useful, though physical therapists can assess such imbalances as well. The key for Stages is: power differential between legs has no significant influence on ride data and its value as a training tool.

Installation of the Chorus Power Meter is just a matter of replacing your existing left side crankarm with the Stages version. No magnets, zipties sensors or additional hardware required. Done. The head unit pairing and Zero calibration tasks are just as simple. The Stages unit is equipped with an accelerometer that tracks crank position during rotation to calculate cadence. It sends the cadence and power information to your connected devices. The self-contained unit means that from installing the power meter to riding generally takes about 10 minutes. Install, pair the power meter to a compatible head unit, Zero calibrate, go ride. Stages even provides excellent instructions and support through their website.

While there are power meters on the market with price ranges well into thousands of dollars, and with a bevy features and capabilities, generating, measuring and applying power data for use by most cyclists can be achieved with the left arm Stages unit. For example, the engineers found through thousands of miles of testing research that power differential between legs has no significant influence on ride data and its value as a training tool. This helps to significantly reduce complexity and cost while providing power measurement with ±2% accuracy. The left arm measurement is taken and doubled for so-called total power. Stages's assumption of symmetry also gives major advantages over crank spider based torque measurements.

It is crucial for accurate training and analysis that the meter be consistent to itself, that the rider can quickly and easily set Zero calibration at the start of every ride, and that temperature is always accounted for. Stages constantly corrects for temperature via Active Temperature Compensation (ATC) which takes place automatically and continuously while you pedal, allowing you to simply ride and use utilize your data without worrying about manual adjustments. Accuracy is much better over many of it's competitors (whose units don't auto correct, or do so with far less frequency) whenever there is a significant change in temperature during your ride. Temperature can seriously affect the strain gage systems used to measure power, to the point where a long climb in the mountains during which weather and temperatures can greatly fluctuate, uncorrected data is nearly worthless.

Stages installs the unit on the arm. The location on the arm is crucial, as the arm and pod then tested and calibrated together to ensure that the strain gages and sensors are working optimally with each specific crank arm. The pod itself is made of an incredibly strong polycarbonate blend that is similar material to that used in bulletproof glass. This material is perfect due to its light weight, superior durability and impact protection, so there is very little chance of an impact breaking the housing without also seriously damaging the crank arm. Additionally, the Stages Power Meter is highly sealed against environmental conditions, and carries an IPX7 water resistance rating, which means it can be submerged in water up to 1 meter for a maximum of 30 minutes. Please keep in mind that this does not mean that you use a pressure washer on the unit. We highly recommend you never pressure wash near the bottom bracket/ crank assembly of any bike.

It was crucial to Stages to make their power meter efficient, as well as keep their firmware updated. This version of the Stages Power Meter is their Gen2 pod, which is more streamlined than the original model (allowing for more crank arm and frame compatibility). The battery compartment and door were improved and strengthened. It is easy to change the battery, a coin-style, readily available CR2032 model. Each CR2032 delivers 200+ hours of power to the unit. The StagesPOWER App also keeps track of the battery level, so you can be prepared. Firmware is updated via this smartphone app as well. Stages regularly advances their firmware and app to reflect new features and updates. The app is user friendly and will become your best friend as you manage your power meter, allowing for direct updates to Training Peaks, Strava, Garmin Training Center and other cloud-based training systems.