Quarq’s current generation XX1 power meter has been redesigned to work exclusively with SRAM’s one-by gearing systems and features a variety of crank lengths, Q factors and BB types to suit nearly every bike. The brand has built an impressive reputation in a fairly short space of time, and its roadie Elsa RS offering came out on top in BikeRadar's 2016 best power meters shootout.
Ours came with 175mm crank arms, a 168mm Q factor and a GXP BB fitment, so just needed an 8mm Allen key and five minutes to fit. Pairing to an ANT+ compatible device is also easy and so far we haven’t had any issues with our Garmin not finding or recognising the power meter.
The Quarq power meter has a claimed accuracy of + or – 1.5% and our testing seems to bear this out. We cross-referenced our Strava times against power readings and the numbers added up.
Older power meters were susceptible to temperature changes, but Quarq has addressed this with what it calls multipoint temperature compensation. This basically means every power meter is individually calibrated at the factory, hopefully eliminating temperature effects on power measurement.
We carried out most of our testing during the British winter, so it’s hard to make an accurate assessment of these claims, but the test bike regularly goes from a warm house into the frigid morning air and so far we’ve not experienced any power drift or unexpected readings.
At 712g all in, it’s slightly heavier than Rotor’s rival Rex 1.1 INpower alloy crank. But this is probably due to the more elaborate (and accurate) strain-gauge hardware.
One small issue worth noting is that SRAM’s carbon XX1 crank arms aren’t the stiffest around, with noticeable flex when stamping on the pedals. It’s not so bad for lighter riders, but a heavier rider may suffer from unwanted give. That said, current cross country world champion Nino Schurter certainly doesn’t seem to suffer with XX1 crank arms and he’s putting out some serious watts.
This article was originally published in What Mountain Bike magazine.