Quarq DFour91 Power Meter Crank Arms - GXP Carbon, 170mm/110 Asymmetric BCD

Description

The dfour91, like its sister, the dfour, uses the same gauge as the dzero model drops, but a bolt-on fit to a Shimano drivetrain specifically, Shimano DuraAce 9100. Unlike its predecessor, the dfour, the d9100 is not compatible with Shimano DuraAce 9000, Ultegra, or 105 groupsets, although it is also capable of running Ultegra R8000 chainrings. With the exception of the compatibility difference, the DFour91 includes all of the DZero's technology packed into its Spider, most importantly the power meter itself. The power meter saw some hefty reworking, with Quarq Claiming 150 documented improvements, asserting leaps and bounds of advancement over previous models, with the most important improvements made to the voltage measurement and gauge circuits at the heart of the meter . As with previous models, the Dfour91 incorporates five meticulously placed tension gauges throughout the spider, designed to measure how many Newton meters you're putting out when you hammer on the pedals. And that still incorporates the same level of precision as claimed at +/1. 5%, keeping it 0.5% more accurate than more meters. One of our favorite features, however, is that the new design doesn't require as much correction in order to maintain precision over massive temperature ranges, allowing things to work smoother when the mercury drops. This means that the Dfour91, like the Dfour, is better at rationing battery life through changing weather, but when the battery is die out, it is still easy to change without tools or tedious procedures. The 10K Dynamic Quarq temperature compensation technology graces us with its presence in the Dfour91, relieving us from the constant stress of midrace to zero when temperatures fluctuate over long alpine climbs, or early morning runs on warm days. pm. While making corrections may seem like they come at a minuscule cost of coasting for a couple of seconds, it can make all the difference between the podium and concrete come race day. Not to mention the...