The SRAM Quarq Quatro MTB Powermeter BB30 Double Chainset brings a lightweight, easy-to-use, versatile and durable power meter to mountain biking. The Quarq features carbon crank arms, CNC machined 7mm AL rings and X-Glide shifting technology, and is compatible with all of SRAM's 2X10 MTB Groupsets. It weighs 723 grams (175mm, BB30) and the waterproof design is ready for creek crossings and hose downs.
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. A wireless standard for bicycle electronics that ensures interoperability between sensors and bike computers from different manufacturers.