Industry literature discussing powermeters is replete with hyperbolic claims, but Quarq's SRAM Red DZero Power Meter Crank Arms for GXP bottom brackets enjoy a pedigree that speaks for itself. The Red DZero is the latest member of a family that includes wins in the most prestigious races in the world, ranging from Roubaix to Paris and Kona. It incorporates every advancement that Quarq has made in power meter technology over the last decade, and it combines those advancements with an improved measurement circuit for even more accurate data across variable external conditions. As with the rest of the DZero line, the Red model still incorporates five strain gauges strategically placed throughout the spider in order to measure the Newton meters you're throwing into the pedals, and--except for the alloy spider--it features the same Exogram carbon crank arms and graphical treatment as the standard Red crank. It's also still got the same claimed accuracy of +/- 1. 5%, so its numbers are 0. 5% more accurate than most meters, but the new design requires less correction in order to maintain accuracy in drastic temperature changes. Fewer corrections mean the latest SRAM Red power meter model also better rations battery life than the previous generations, though when the battery does go out, you can still change it without tools or having to ship the whole thing to the manufacturer. The Red DZero system's accuracy is further boosted by the return of Quarq's 10k dynamic temperature compensation technology, which alleviates the need for constant, mid-race zeroings in variable conditions. Even if it's just coasting for a few seconds or toggling through your head unit to the proper option, it can still be the difference between winning and losing. It's also obnoxious as hell. The DZero is equipped with an auto-adjust schedule based on a constellation of around 10,000 data points that chart how the unit responds to temperatures ranging from zero to 130 degrees Fahrenheit. This le...

• Arm Material: Exogram Hollow Carbon
• Arm Length: 165 mm, 170 mm, 172.5 mm, 175 mm
• Bolt Circle Diameter: [compact] 110 mm, [standard] 130 mm
• Bolts: hidden bolt (HB) pattern only
• Rings: 1 or 2

Arm Material: Exogram Hollow CarbonQuarq