Manufactured by Canada-based 4iiii is the first of our bike power meters in our 2020 buyers guide. It measures left leg power within a claimed 1% accuracy. It’s a lightweight option, adding just 9 grams to the left crankarm’s weight. It can also be installed in minutes by most bike owners with a handful of tools. It comes “Ride Ready” fitted to either a Shimano 105, Ultegra or Dura Ace crank. It is also available with a full chain ring set that allows dual readings from both legs. The electronics are built into a small unit (29mm x 8mm x 38mm) that is actually smaller than most cadence sensors.
4iiii can use both ANT+ and Bluetooth Smart so the cranks will communicate with smartphones too. Connection to devices is quick and provides a remote indicator on battery life. Battery performance compared to others is good with over 100 hours of battery life. In a hugely competitive market the 4iiii Precision power meter is a relative steal offering access to power data for real world money.