The Quarq XX1 GXP Power Meter was built from the ground up to work specifically with SRAM's revered single ring drivetrains, outfitting your GXP bottom bracket with premier power meter technology. With Quarq, the XX1 Power Meter features a seamless design. The carbon XX1 crank arms, combined with CNC machined aluminum spider that houses the power meter, offers a high performance crankset that weighs in at a svelte 626 grams. The Quarq SRAM XX1 Power Meter is equipped with Power Balance technology, which measures and displays the power you're generating in both crank arms separately. Power Balance offers you a more precise comparison between each leg, and thus an easier way to target weaknesses and plan for improvement. While the battery of Quarq SRAM XX1 Power Meter is predicted for 300hours of ride time, it also features a tool free user replacement system. This means you no longer need backup cranksets, and the ability to switch the battery yourself is far better than having to mail in the crankset for a replacement, which is what other systems require. Most importantly, the XX1 Power Meter measures with precision, claiming an accuracy of 1. 5% which is 0. 5% more accuracy than most meters. Quarq does this by measuring watts with five strain gauges strategically placed throughout the spider in order to measure the Newtons you're throwing into the pedals. Also, the XX1 Power Meter eliminates the headache of wildly variable temperatures with a dynamic temperature compensation that features over 10,000 data points, which means it figures out the atmospheric details for you with minimal drift, so you can focus on pedaling instead of toggling. To boot, Quarq's power meter is waterproof for 30 minutes while submerged under one meter of water. The XX1 Power Meter communicates to your head unit via ANT wireless, so most likely it's compatible with your current computer. It measure cadence with an AxCad accelerometer, and it's compatible with various...