Smithers MINNEAPOLIS

Quarq

As per Krusers request, I checked out the Quarq power measurement system at INTERBIKE this year.

These guys are onto something.

The first part of the system is the CinQo crankarm spider. This unit, which will replace the original spider on some FSA, Truvativ, Cannondale, Rotor and Specialized cranksets, has a built in strain gauge to measure power output.

The representatives at Quarq explained to me that they think there are only two ways to accurately measure power output on a bike, via the rear hub or via the crank. They chose the crank.

The second element of the Quarq system is the Qranium, the computer/display that mounts on the handlebar.

A fully functional computer, including 512mb of memory and a GPS chip, the Qranium is probably the most powerful bicycle computer ever made. It’s compatible with CyclingPeaks software and, since it uses the Linux open source code, it is completely customizable by someone who is familiar with the Linux operating system. Not just customizable in regards to display options, but users can write their own programs, load them onto the Qranium and run them as they would run any program on a PC. Quarq is hoping that a community of programmers will write and share their work using online message boards.

While the Qranium uses a built in rechargeable Lithium Ion battery, the CinQo uses a simple CR2450 user replaceable watch battery to communicate with the computer. Quarq can get away with using such a low power sensor at the crankarm due to the fact that they have chosen to use the ANT+SPORT communication technology.

ANT+SPORT is a 2.4GHz wireless networking protocol that uses very little power and is very small. This allows a system using ANT+SPORT to run for potentially years before a battery change is required and can be used in small sensor applications as appropriate for bicycle sensors. Quarq has chosen ANT+SPORT not just for these reasons, but also because of the fact that ANT+SPORT devices can communicated with any ANT+SPORT sensors. This means that the Qranium can read data from other manufacturers ANT+SPORT sensors (such as the Garmin speed and cadence sensor), and the CinQo can send data to other manufacturers ANT+SPORT computers.

Price? You can spend $2300 – 3600 on an SRM power meter, or you can spend $2190 on the Quarq system. I think it’s considerably lighter than the SRM and it appears to be much more customizable.

Current limitations of the system include the fact that the CinQo is only compatible with cranksets that have a replaceable chainring spider. Quarq is in the process of developing a crank system compatible with any crankset so this problem will be solved in the near term. The size/weight of the sensor will continue to be reduced.

I’ll never buy this thing because I am not that serious about on the road training. But if I was interested in measuring watts on the road I would not hesitate to get the Quarq system.