Canadian firm 4iiii Innovations is now selling its Precision Pro dual-sided power meter, which only adds 25g to a crankset, the company claims. As with the company’s left-side-only Precision, you can send in your current crankset and 4iiii will install the meter onto it (called Factory Install), or you can buy what 4iiii calls Ride Ready — a new crankset with a meter installed. The Dura-Ace 9000 Precision Pro goes for $749 (about £570) with the Factory Install option. Ride Ready Dura-Ace 9000 cranks are $1,499 (about £1,140).
The Precision Pro has strain gauges on both arms for distinct right and let power measurement. It works on both ANT+ (for most head units like Garmin Edge devices) and Bluetooth (for smartphones). The firmware is upgradeable over Bluetooth with the 4iiii iOS and Android apps.
Tom Boonen and the rest of Etixx-Quick Step have been racing on Precision Pro meters this year Ben Delaney / Immediate Media
Stages was the first company to offer a crank-based power meter with strain gauges in the left arm. 4iiii followed, and now Pioneer also has a left-arm meter. Garmin’s pedal-based Vector 2 has a left-side-only option (the Vector 2S), and Rotor’s INpower measures on the left. In each of the products, the left-side measurement is doubled for a total wattage number.
Some other power meters, such as SRM, Quarq or Power2Max, measure the input from both legs, but not distinctly. Quarq and Power2Max offer left/right calculations, based on where in the stroke power is applied, but not actual measurements for each leg.
With this dual-leg system, 4iiii joins like likes of Pioneer, Verve InfoCrank and Garmin Vector with distinct left/right measurement.
“Power helps riders focus on how their body responds to training, ” said Karel Bergmann, 4iiii’s Precision product manager. “While single-sided power meters meet the needs of most riders, dual-sided power provides an extra level of data for those who are fine tuning their training or monitoring strength progressions during recovery from an injury.”
This is Boonen’s Precision Pro that he used at the 2016 Paris-Roubaix, where he placed second Ben Delaney / Immediate Media