Pioneer Shimano Dura Ace R9100 Single Leg Power Meter Crank Arm

If you've just upgraded to Shimano's latest flagship drivetrain, we'd understand why you might be a bit uneasy about springing for a full, dual leg power setup. Pioneer's Dura Ace R9100 Single Leg Power Meter Crank Arm lets you quantify the gains in efficiency made by Shimano's crankset redesign, letting you track your physical progress as you progress toward upgrading to a full power meter. Or not. The single leg approach may not let you parse out the power production nuances of each leg individually, but it does provide a full number in order to chart your total output. For most cyclists, that's more than enough to get a leg up on their goals. The Single Leg Power Meter is an impressive piece of tech on its own, and since it broadcasts wirelessly with ANT, chances are good that it's already compatible with your current head unit or wearable. It measures pedaling force, direction, and overall efficiency by monitoring 12 points of rotation at 30 degree intervals across the pedal stroke. At each point, the deflection caused by radial and tangential forces on the crank arm is scanned 16 times to ensure a claimed 2% accuracy. The system's Active Temperature Memory Adjustment feature maintains that accuracy in temperatures ranging from 14 to 122 degrees Fahrenheit, so it stays on point even in extreme conditions. This eliminates the need to freewheel in the middle of a race in order to zero the system, a situation that can cost you precious momentum during a solo effort or make you lose your safe position near the front just as the race hits a climb. The unit also has a waterproof rating of IPX6 and IPX7, so it can handle inclement conditions as well as extreme temperatures.