Quarq’s Elsa 10R is a spider-based power meter that uses five strain gauges to measure the driveside torque. It’s simple to set up and use and produced reliable data during the course of our test, the averages all being within six watts of our control meter and peak 10-second power typically 15 watts higher.
We found that when taking it from a warm room to the cold outdoors it would read around 10 watts higher than the control meter for around 10 minutes until it had adjusted to the cooler temperatures. This is by no means a deal breaker but also not quite as good as many other meters we've tested.
Quarq has one of the highest sampling rates of any power meter, reportedly over 5000Hz (5000 times per second). But Quarq doesn’t have its own head unit so you’re limited to ANT+, which will only record and display data at 1Hz. That’s a lot of data going to waste right now, but it could be useful with a more advanced head unit in future.
The Quarq Elsa 10R is easier to use than its predecessors, you don’t need to recalibrate if you change chainrings and you can quickly change the CR2032 battery. It quickly pairs with ANT+ head units and zeroing the torque before each ride is simple.
Quarq also gives you a left/right balance reading called Power Balance, which according to the maker is ‘the ratio of power generated in the right drive stroke (first half) versus the left drive stroke (second half) for each crank revolution’. This is not quite the same as left/right balance measured by other power meters (Vector, Rotor and Factor) but in practice it wasn’t much different.
We found Quarq’s main downside to be durability. One of our testers had numerous problems with his unit (it would jump from normal to crazy data, or not work at all), which were never satisfactorily resolved. Still, this is a problem not unique to Quarq – power meters are fragile things.