The Limits cycling power meter may be the simplest, cheapest one yet
Competitive cyclists like to track their power output, and many use a power meter in order to do so. Those meters mostly take the form of a device that's either added to or built into one crank arm, and they can cost anywhere from around US$1,000 to over $2,000. The Limits power meter, however, simply goes between the pedal and crank of any bike, and is planned to cost less than $400.
Created by a team led by Scottish engineers Ken Norton and Gordon Drummond, the Limits is threaded onto the pedal receptacle of the left crank arm, and then the existing pedal is threaded onto it. A dummy device is also included for use on the right-hand crank, to keep the spacing consistent on both sides.
This setup not only means that users don't have to wonder about compatibility with their current drivetrain, but they can also swap the device between multiple bikes. The designers claim that the gap created between the pedals and cranks shouldn't negatively affect the bike's fit, and in fact may even help alleviate knee pain.
Once in place, the waterproof power meter measures cadence (via an inclinometer) and torque (via strain gauges). Using these two data points, it is then able to calculate power output in real time. It's powered by a replaceable coin cell battery, that reportedly should be good for about a year of use.
Users will also require a third-party cycling computer that uses the ANT+ wireless protocol, in order to see what the Limits has to report.
Norton and Drummond are currently raising production funds for their device, on Indiegogo. Although the planned retail price is $384, a pledge of $249 will currently get you one – assuming all goes according to plans.
More information is available in the pitch video below.