This article originally appeared on BikeRadar
The Elsa RS is Quarq's top-of-the-line model made for Shimano four-bolt chainrings.
Quarq has come a long way in a relatively short time, with constant updates and innovations since its launch back in 2008. Since being bought by SRAM in 2011, the pace of progress has only increased and we've seen a flurry of new features and price drops. This lightweight model with hollow carbon cranks is great value and every other version, right down to the entry-level Riken AL, features all the same measurement hardware.
The Elsa RS certainly looks the part, blending perfectly into a Dura-Ace drivetrain. Indeed, it's worth noting that it seems optimised for Dura-Ace – when we replaced an Ultegra 6800 crank with the Elsa RS unit during 2015 testing, the original Ultegra chainrings fitted easily, with the Hollowglide outer ring not completely flush with a spider, creating a small step between the two. This had no effect at all on function though, with Shimano's typically slick changes identical to before.
- Highs: Accuracy, consistency, simplicity, value
- Lows: Apart from its dura-ace-centric fit, nothing
- Buy if: You're a power-hungry shimano user after an attractive, foolproof alternative
The most significant of several recent developments by Quarq is the switch to accelerometers in place of a magnet for cadence. It makes installation much easier because you're simply fitting another crankset. Pairing is easy anyway, and helped further by the thoughtful inclusion of an LED status light and the ANT+ ID on the outside.
Quarq meters measure power at the spider, like an SRM. It's a good method as it means the expensive and fragile bits are tucked neatly away where they're hard to damage. It does mean that left and right power can't be measured independently but Quarq has beaten SRM to a trick by using crank position to calculate the effort from each leg. It's just as good and always gave the same split as whichever power meter pedals we were running.
Another crucial feature is Quarq's '10K' temperature compensation algorithm. Older models were more vulnerable to temperature variation but this one has it covered. You should still do a pre-ride manual zero offset but after that the Elsa RS does it all.
Over hundreds of miles the Elsa RS never put a foot wrong. It responded quickly, tracked well with other meters, caught sprints well and never gave us any grief. That there is so little to say about its performance actually says everything – it's brilliant.