Sram Red Quarq
Type: Crank-based power meter, meaning it can alternate between racing and training wheels, but swapping the meter between bikes takes some mechanical knowledge.
Benefit: Cheapest crank-based meter
Drawback: Comes without necessary accessories or computer
Getting it to work: Installation of this power meter is no different than installing a crankset, which is much simpler than it sounds. Once you become comfortable with the basic steps required, the Quarq can be swapped from one bike to another in a matter of minutes. The crankset comes without any electronic accessories, so you’ll need an ANT+ compatible computer and analysis software such as Training Peaks. It is part of Sram’s flagship 2012 Red component group and must be paired with the corresponding front derailleur and shifter for optimal gear changes. Riders without Red run the risk of compromising shift quality.
What it does: Power created during the first half of the stroke can be separated from the second half and displayed on a Garmin Edge 500, 800 or Forerunner 910XT, giving an approximation of the balance between the right and left legs. Note that the power balance ratio is not directly measuring the effort independently applied from your left and right side. On most occasions the average leg balance data from a ride has been 49/51 percent, and there was one particular recovery ride when riding with a sore knee that the balance reported was 46/54 percent.
How well it works: This unit worked reliably in a wide variety of weather conditions straight out of the box. The power meter syncs quite easily with Garmin ANT+ enabled devices and manual calibration is also quite easy, although it does require pushing a lot of buttons. The unit can also be automatically recalibrated during the course of a ride by back-spinning the pedals several revolutions, but it doesn’t signal that it has in fact recalibrated, leaving the tester a little unsure. It is available with standard (53/39) or compact (50/34) gearing with crank length as short as 170mm. The battery, which will need replacement once or twice a year, can be bought for a few dollars at most drug stores and takes less than two minutes to install.
Buy it for: Versatility, dependability and advanced features.