Elsa 10R

Brand: SRAM

Spider-based power meter from Quarq, the maker of power-metering cranksets bought by SRAM in 2011, announced in 2013 as a non-SRAM-RED option in the range. Five strain gauges measure torque on the drive side, and Quarq's OmniCal allows chainrings to be changed without recalibration. It transmits over ANT+ only and runs on a user-replaceable CR2032 battery.