Interbike: Quarq power meter & real bike computer

Linux for your handlebars

One of the most intriguing launches at Interbike was a pairing of power measuring crank spider and power meter/global positioning system (GPS)/heart rate monitor/altimeter computer from new company Quarq Technology. What’s especially interesting if you’re a hardcore bike instrumentation geek is that the display unit will run open-source software, so developers will be able to modify it and write applications for it.


The heart of the system is Quarq’s CinQo instrumented crank spider. It will be available to fit a number of existing chainsets from companies such as FSA, Specialized, Truvativ, Cannondale and Sibex Sports. In short, if your cranks have a removable spider, Quarq plans to have an instrumented spider for you.

Quarq claims the accuracy of its strain gauge-based instrument is an a par with power devices that use similar technology, but where it differs from its rivals is in the adoption of the Dynastream Innovations Ant+Sport Bike Power interface, a wireless standard that allows the spider to be used with any compatible handlebar unit.

GPS manufacturer Garmin owns Dynastream Innovations, so it’s no surprise that the CinQo will work with Garmin’s recently-announced Edge 705 GPS bike computer. It should also work with SRM’s forthcoming ANT+Sport handlebar unit. More interesting to folks who have a need for what you might call a true bike computer, is that it will work with Quarq’s own Qranium handlebar unit.

Running a cut-down version of the Debian Linux operating system, the Qranium boasts 512MB of RAM, the ability to communicate with four ANT+Sport devices at once, a barometric altimeter, 20-channel GPS and a USB interface for charging and communication. It will run Quarq’s own open-source software, so the source code for the software will be available for anyone to read and modify.

The combination of the device’s open-source roots and that USB interface means that programmers will be able to write applications to add to the unit’s capabilities if there are functions people want that aren’t provided out of the box.

For example, according to a couple of developers-cum-bike riders we’ve spoken to, you could connect a GPRS modem and relay live data to a website, or write an auto-blogging script, that at the end of each ride takes the ride log and pushes it to a blog – or sends it straight to your coach. Or, more frivolously, use USB headphones and use it to store music for your ride.

The Qranium works with its own ANT+Sport heart rate strap, and also with Polar analogue straps.


Quarq hopes to have the Cinqo spider and Qranium bike computer available in the first quarter of 2008. The CinQo will retail for US$1,195 and the Qranium for US$995.