Quarq technology powers the SRAM S2275 Quarq Power Meter used by XC world champions Jaroslav Kulhavy and Nino Schurter, and the BlackBox DH power meters used by Danny Hart and Sam Hill.
How Power Meters Work
Power meters calculate power by measuring the torque (pedal force) and the angular velocity (cadence). Power = Torque x Cadence.
When you press on the pedals, all parts of the bikes drivetrain displace (flex) slightly under the load. Power meters are designed using Finite Element Analysis to displace in a very controlled manner in specific locations in response to applied load. Strain gauges are used to measure the displacement and thus calculate the applied torque. Reed switches are used to calculate cadence.
SRAM power meters use a proprietary strain gauge arrangement and precision digital circuitry to delivery high accuracy and low power consumption for optimal battery life.
Inside Quarq Power Meters
ANT+™: A wireless standard for bicycle electronics that ensures interoperability between sensors and bike computers from different manufacturers.