Tempo Crank-Based Power Meter

As the struggle for supreme power continues in the realm of cycling power meters, price is rapidly becoming as much of a consideration as accuracy. 

The latest in the out-cropping of affordable power meter solutions, comes from the the crowd-funding campaign of Tempo.

Using a similar design platform to that of the popular Stages power crank, the Forida-based Tempo reduces costs by virtue of the fact, that the purchaser supplies his or her crank arm, and Tempo simply installs their sensor to it, via a high strength bonding adhesive.

The sensor itself is encased in an impact and water resistant plastic molded case, which measures 33mm x 60mm, and is just 10.5mm thick.

The Tempo power meter is currently available to fit most Shimano cranks, as well as some FSA models, with the goal of developing a carbon fiber compatible version in the future.

more from Tempo…

Product Status:

The Tempo power meter is a crank arm based power meter full of features and performance. Some of the notable features include:

• It already works! The unit is working and ready to go. There are full working prototypes that have been tested and used. See the video for the data output.
• Ant+ compliant so it works with all head units, watches, and smartphones that are ANT+ capable.
• Excellent battery life. Battery life is expected to be over 200 hours. Battery can be easily replaced by the user.
• Cadence reading down to zero. Most other power meters must reach 20 rpm to begin registering. The Tempo reads down to zero.
• User programmable slope. You can change the slope based on your riding style. You can calibrate it to your current power meter for a second bicycle. (Requires ANT+ USB stick)
• Calibrated and temperature compensated sensors.
• Simple user calibration procedure.
• Battery level reporting with actual voltage measurements.
• Professionally bonded strain gage sensors.
• Over the air update enabled for software upgrades. (Requires ANT+ USB stick)
• Designed, built, tested, manufactured and assembled in the USA.

As of now here is the current status of the project:

• All electronic hardware design completed and tested. Factories have all designs and are on standby for production of hardware
• All software written and is currently being Beta tested. Any inputs from the riders are being included in the updates. Software updates can be pushed to units at any time
• Casedesign is 90% completed. The current units are all 3D printed and being optimized for robustness and water sealing. Once the case is optimized, hard tooling will begin
• Lead times are governed by the availability of crank arms. Crank arms are expected to arrive June-July.

Funding is needed for inventory, housing tools, software licenses, and test fixtures. None of the funding is for development since the unit is already working.

FAQ:

What are the dimensions of the power meter?

-The unit is 10.5mm (0.4 in) thick, 33mm wide (1.3 in), and 60mm (2.4 in) long.

Is the power meter going to be 3D printed or injection molded?

-The power meter case will be injection molded using high quality plastic. It will be resistant to impact and water. The 3D printed models shown are only for prototyping. The funding will be used to make the injection molded tools.

Can it measure cadence?

-Yes! The meter can report cadence without the use of a magnet.

How is it attached to the crank arm?

-The Tempo power meter is bonded to the arm using a high strength adhesive. There are no pockets or cuts made to the crank arm thus keeping is original structural integrity.

Are carbon crank arms available?

-Not yet. Once the campaign is successfully funded, we are going to proceed and being to develop units that will work with carbon cranks arm

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