Anyone who's had the opportunity to pedal an XX1 Eagle bike in anger will likely agree that the 12-speed, flagship drivetrain is the epitome of SRAM technological development. Anyone who's used Quarq's flagship DZero powermeter to count the watts produced by angry pedaling will also likely agree with Quarq that it's the epitome of that brand's technology. When the two are combined in the GXP-compatible Quarq SRAM XX1 Eagle DZero Power Meter Crank Arms, well, good things are bound to happen.Before going any further, we should note that, unlike the standard, direct-mount XX1 Eagle and vanilla XX1 cranksets, the DZero Eagle features a four-bolt spider compatible with an X-Sync 2 (XX1 Eagle) or X-Sync (XX1) 104 BCD chainring. We do like the simplicity and modularity of the direct-mount chainring design, but the powermeter's strain gauges and electronics live in the spider, so eliminating it isn't an option in the Quarq system.
As with the rest of the DZero line, the XX1 model 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 DZero system's accuracy is further boosted by the return of Quarq's 10k dynamic temperature compensation technology, which alleviates the need for constant zeroings in the variable conditions often encountered over the course of long days in the mountains. 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 lets the power meter figure out the atmospheric details for you with minimal drift, so you can focus on turning those Carbon Tuned crank arms, not babysitting them.
As with the previous Quarq models, the DZero XX1 also plays host to Power Balance and Omnical features, which record total output and output for either leg individually (Power Balance) and let you swap chainrings without recalibrating or negatively impacting accuracy (Omnical). As with previous Quarq models, the DZero communicates to your head unit via ANT+ wireless, but Quarq also adds Bluetooth to this generation. Up till now, we've always tempered the obligatory head unit-compatibility statement by writing that your current computer is likely already compatible with the power meter; now, we can just state outright that it is compatible.
We recognize that there is value in components that can stand up to the unexpected obstacles we often encounter when the trail turns funky, but Quarq demonstrates its penchant for being overly thorough by ensuring that the unit's internals can handle comically extreme conditions. The system is waterproof for 30 minutes while submerged under one meter of water, a feature that will come in handy on days when, well, we've all had days where long term submergibility would benefit our gear. Those days typically don't end well for our bodies, and losing expensive gear to a tumble into a stream just adds insult to injury.
Since the DZero is effectively a catch-all for almost every bit of tech Quarq has thrown at the power meter problem over the past decade, it includes the AxCad accelerometer, which provides cadence information without any additional sensors or magnets. The DZero is also compatible with training software suites including Training Peaks WKO+, Training Peaks, Golden Cheetah, and Strava. Unlike previous versions, the DZero's Bluetooth compatibility lets it sync with the Qalvin BLE app to easily tune, tweak, and set zero offsets.
- Fly the flagship models from sister companies SRAM and Quarq
- Improved precision from redesigned strain gauge circuits
- Provides power for right and left legs separately
- XX1 Carbon Tuned crank arms for uncompromising stiffness
- Broadcasts via ANT+ and Bluetooth protocols
- Requires less correction for better data and longer battery life
- Battery can be changed by home mechanics without tools
- Compatible with GXP bottom brackets and adapters