Power Up, pt 2: Quarq and Wahoo

article & images by Nick Salazar

Dec 24, 2011   34,020

Quarq power. SRAM rings. 165mm crank arms. For me, it doesn't get much better than this.

My experience with the Quarq power meter has been, in a word, delightful. I got the crank from UPS one night around 6pm, and I started my first trainer ride on it at 6:30. Most of that time was spent trying to swap out the bearings on the frustrating and ultra-tight-fitting BB90 on my Speed Concept. But once the bearings were swapped, I used some superglue to put a cadence magnet on my frame, as per Quarq's instructions, then popped on the crank.

The Quarq comes fully assembled and ready to go. No special setup. No calibrations, no hassle, no swearing at your bike. Just install the crank as normal, and it works. It's awesome.

The pairing process was also dead simple. Just pedal the Quarq a couple times, which wakes it up, and then initiate the pairing procedure from the head unit. In my case, it was my iPhone, equipped with the Wahoo ANT+ Key and running the Wahoo Fitness app. You just tell it in your workout settings that you have a power meter, and it identifies and pairs the thing for you. I was getting power and cadence numbers from the Quarq immediately. Seriously, from the time I launched the app to the time I was pedaling with power was probably about 30 seconds. I never had to crack a manual open. This is a fantastic combination.

In over a month of using the Quarq on every ride, I haven't had a single issue. No dropouts, no weird numbers, just pure performance. In the realm of how the device works, there's very little to say. It just does. Flawlessly. The finer points of the Quarq are where it really starts to distinguish itself.

The Small Things

The user calibration software, Qalvin, is one reason Quarq's future looks so bright.

First of all, the battery is user-replaceable, meaning you don't have to send the unit in for service every couple years (SRM owners have to do that). And the other big feature here is that the Quarq can now be user-calibrated as well. What's that mean?

Troy Hoskin of Quarq had this to say: "The best example to illustrate this is the change from road to TT rings. In most cases, fitting solid TT rings stiffens up the system and more mechanical torque (pedal force) is applied to the strain gauges for an equivalent force on the pedals. This in turn makes the power meter read higher. The slope, or multiplier, must be decreased so that power data is accurate again. User calibration enables you to adjust the slope yourself."

So as long as you always keep the same rings on your crank, you'll never really need to re-calibrate the Quarq. But if you ever swap to a different kind of ring, you need to re-calibrate. For some additional technical reading, see the Strain Gauge Technology section at the bottom of this page, and also check out this article.

Recalibration used to require sending the crank back to Quarq. But not anymore. They've published an app in the Apple app store called Qalvin (no Android version just yet). And, as you imagine, it lets you fiddle with the slope on your own. The procedure for calibrating new rings is fairly simple, but does require that you have a heavy weight (44 lbs or greater), and that you know its actual mass with great precision. Quarq has a great instructional video on how the process works.

Many users will never get into Qalvin, but it's really nice to know it's there should you ever need it. Plus, if you calculate the slope of two different sets of rings, you could swap rings and then re-enter the slope values without re-calibrating. This could be really nice if you like to swap rings based on the course or terrain you're riding.

Of course, all the data coming off the device is meaningless without the devices you're using to see it. Hit the jump for the impromptu head unit that became my mainstay.

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