Power Meters

Whether you're looking to take your training to the next level or you simply want a better way to measure energy expenditure, a power meter is your best bet. And the Power Cranks 105 Upgrade Kit are no exception. With our lightweight power sensors on a Shimano 105 crankarm, it's the perfect way to enter the power meter game. The development of Power Cranks began with our Human Performance Team looking at riders in realistic scenarios on the bike. Historically, power meters have been validated by two different methods—one is by measuring the produced torque by applying a static, linear load to a crankarm or chainring, while the second uses a power generating motor to pedal the bike. Well, cycling is neither static nor linear, and humans apply power much differently than a machine. So, we found that neither of these methods answer the "real-world" accuracy question. To get the best test for accuracy, in all types of riding scenarios, we built our own cycling treadmill, the WinMill, to measure power output to a known truth. This new benchmark lets us evaluate accuracy under all riding conditions—seated versus standing, various power and cadence levels, different weights, and a myriad of gear. This data acquisition process is our gold-standard for testing power meters, and through our testing and external validation from the Locomotion lab in Boulder, Colorado, Power Cranks have been proven to have the highest accuracy in real world scenarios (+/- 1.5%). The Power Cranks are also easy to live with, with class-leading temperature compensation firmware and waterproof enclosures. Calibration is only required during seasonal-type fluctuations in temperature, and the included wrench makes battery swaps a breeze. +/- 1.5% real-world accuracy tested on the WinMill and validated by the Locomotion Lab in Boulder, CO. Available in 170-175mm crankarm lengths. Easy set-up and diagnostics with the Specialized Power app. (iOS and Android versions available). Right crankarm and spider NOT included. Shimano 5800 generation 105 left-side power measurement. Works with ANT+ and Bluetooth® devices.

Rally RS100 is tested to the extreme, so you can ride there too. This single-sensing power meter delivers reliable power measurements and is easy to transfer between bikes, no matter what bike you're on or where you're riding. - Impeccably Designed Pedal—Rally power meters have undergone rigorous testing to increase reliability. Featuring a superior design with sensors housed inside, this pedal installs like any other pedal. And it's quick to transfer between bikes. - Reliable Readings—By reliably measuring your cadence and forces detected on the left pedal, Rally RS100 doubles the value to provide total power. Want more metrics? Upgrade later to the dual-sensing system (sold separately). - Cleat Compatibility—For a comfortable ride, this pedal is designed to fit your favorite Shimano SPD-SL cleats. - Transferable Spindle—From road to gravel to cyclocross and much more, keep riding year-round with a transferable spindle that can be installed in the Rally RS/Rally RK road pedal body kits (each sold separately). - Battery Life—Make sure you're ready for those long rides and training sessions with up to 120 hours of battery life. Specs: - Battery type: LR44/SR44 (x4) or CR1/3N (x2) - Battery life: up to 120 hours - Maximum rider weight: 105kg - Accuracy: +/- 1% - Field calibration - Adjustable release tension - Measurement location: spindle - Communication: ANT+ and BLUETOOTH - Weight: 328g - Water resistance: IPX7 - Cleat type: SPD-SL - Q-factor: 53mm (55mm with provided 2mm washer) - Stack height: 12.2mm In the Box: - Rally RS100 pedals - Cleat hardware - 55mm Q-factor washers - Documentation