Do you have a frameset with a GXP compatible bottom bracket interface? If so, and you have been saving for a high quality, easy to use, incredibly accurate, ANT+ power meter for your Shimano 11 speed drivetrain, you have found your power meter. It is no secret, if you are running Shimano 11 speed, optimal shifting performance is achieved with Shimano's proprietary 4-arm Hollowglide chainrings. Quarq has built a loyal following with their power meters and instead of asking cyclists to compromise shifting, the company now offers the Elsa RS Powermeter. This GXP BB compatible model has been designed to integrate perfectly with your Hollowglide chainrings, both mechanically and aesthetically. The Elsa RS also has a few upgrades that make the unit more accurate and easier to set-up and use, especially with space challenged frames. Quarq's reputation for quality, light weight and cutting edge data collection has been well earned, and now Shimano riders can have their cake, and eat it too. After the race, that is.

The powermeter itself is housed in a CNC machined aluminum spider that is mated to a lightweight Exogram™ Hollow Carbon crank arm with the stepped 24mm GXP spindle. The combination was developed for complete integration. The stiffness and power transfer of the crankset is excellent, and there is zero power loss from the spider design. Your Shimano Hollowglide (Dura-Ace 9000, Ultegra 6800, and 105 5800) chainrings will bolt right on the spider via the same hardware you use with the Shimano crankset. Just follow Shimano's installation specifications. OmniCal calibration ensures that you can install and change rings without impacting the power meter's calibration. The alignment of the four-arm design keeps the Quarq battery compartment completely accessible on the front of the crankset, just above the arm. ANT+ transmission is verified by LED for simple, clear operation, and Quarq makes the ANT+ ID visible to ensure proper connection.

Quarq has installed their AxCad™ accelerometer, which eliminates the need for a cadence magnet. Given the shape and size of the spider, many frames formerly had difficulty accommodating the unit and the magnet. Now the set-up is cleaner and you have more frame clearance. AxCad is a highly reliable measure of cadence while pedaling, and reacts quickly to changes and stoppage. Many power meter manufacturers have struggled to address temperature variation, but the engineers developed new sensors and firmware, called 10K™ temperature compensation, that eliminates temperature effects on power measurement through more frequent, more accurate temperature readings throughout the pedal stroke. Quarq considers the Elsa RS to be accurate in all conditions to within +/- 1.5%, placing it among the most accurate power meters on the market.

ANT+ wireless transmission gives you maximum flexibility in your choice of head units from Garmin, PowerTap, Lezyne, and so on. Syncing your Elsa RS is simple, as is your pre-ride zeroing. All of the usual power measurement metrics are measured and calculated for your head unit and can be downloaded or transferred to your favorite training and analysis programs, such as Training Peaks, Strava, and Golden Cheetah. The widely available CR2032 battery generally delivers 300 hours of transmission before replacement is necessary, so you won't have to worry about losing data. Quarq power meters have an IPX7 waterproof rating, so you ride in the rain all you want. They feature a 2-year warranty, free firmware updates, and strong Quarq-direct support.

The bottom line is that if you have a GXP bottom bracket standard option, and want to run a Quarq powermeter with your Shimano 11-speed drivetrain, the Elsa RSGXP Powermeter was designed just for you. You make no sacrifices in shifting quality or performance and get one of the most accurate power meters available. The 600-650 gram crank weight is competitively light and stiff, so again, no sacrifices.