Installing and Riding with a 4iiii Power Meter on Your Bike

From installation to first ride — what power data actually tells you about your cycling.

A power meter measures exactly how much energy you're putting into the pedals — in watts. Willem installed a 4iiii Precision on his crank arm and discovered that power data changes how you think about cycling.

A power meter is the most honest tool in cycling. Heart rate fluctuates with fatigue, heat, caffeine, and stress. Speed depends on wind and terrain. But watts are watts — a pure measure of your effort.

The 4iiii Precision attaches to your left crank arm. Installation is straightforward: remove the crank arm with a crank puller, attach the sensor pod with the included adhesive, reinstall the crank, and pair via Bluetooth. Willem did it in his living room.

What changes when you ride with power: you stop chasing speed and start managing effort. You learn your sustainable output. You discover that the headwind you're cursing costs exactly 40 watts more than calm air. Training becomes precise.

The data pairs beautifully with Cyclemeter on iPhone and Apple Watch — real-time watt display on your wrist.

From Willem's cycling collection.