Already proven in the pro peloton when paired with Shimano's flagship Dura-Ace drivetrain, the Pioneer Dura-Ace R9100 Bluetooth Power Meter Crankset adds data collection to your training, helps you analyze every ride, and doesn't compromise the drivetrain for those of us who appreciate a build where every component is the same make and model. Its sleek design integrates cleanly onto the crankset and features dual-leg strain gauges for independent pedal data and other detailed metrics. Newly updated, it transmits that data to any Bluetooth LE or ANT+ cycling computer, and pairing it with one of Pioneer's own cycling computers opens up an even wider world of torque vector analysis for those of us who want to dig into the real nitty gritty minutiae in search of marginal gains and a few extra watts. The system measures pedaling force, direction, and overall efficiency via dual strain gauges bonded to the crank arms. Each sensor unit captures 12 points of rotation at 30-degree intervals by measuring minute changes in the shape of the crank caused when force is applied while pedaling. From this, force is calculated in both the direction of rotation and the radial direction. The combination of these two force components indicates the direction in which the total force is being applied, which is shown using the system's force vectors. Also, a magnet ring that attaches to the bottom bracket measures the position of the crank, allowing precise display of the force vectors at every 30-degree interval throughout the rotation. The force vectors for one full rotation are then wirelessly transmitted to any Bluetooth LE or ANT+ head unit via the transmitter module bolted in the crankset's spider. The information centers around pedaling efficiency, giving riders the ability to target inefficiencies for improvement in training and racing. When pedaling efficiency is high, most of the rider's power is being used to rotate the pedals. So, the force measured in the direction of rot...