Single-Side Powermeter

Whether you’re a pro or simply training hard, PRECISION Powermeters deliver industry-leading accuracy, highly dependable cadence data and 3D powermeter technology capable of measuring tri-axial strain on your crank arm. Designed to be reliable, durable and lightweight, compatible with  ANT+ and Bluetooth head units, PRECISION helps you train harder and smarter.

PRECISION Ride Ready comes installed on a new Shimano left crank arm (105, Ultegra, Dura-Ace, Deore XT or XTR). These crank arms will fit bottom brackets using the Hollowtech II interface.


Shimano 105

Shimano Ultegra

Shimano Dura Ace

Shimano XTR

Shimano Deore XT

Shimano GRX

Check your bike frame clearance with the compatibility guide BEFORE placing your order. Any compatibility issues encountered after purchase will be subject to our terms and conditions.


  • 3D powermeter technology (patent pending) measures tri-axial strain on your crank arm
  • Accurate, consistent data
  • Lightweight, compact design
  • Battery status indicator via 4iiii app
  • Compatible with ANT+, Bluetooth Smart head units, smartphones, and other 4iiii products
  • User-friendly app and configurable rider compensation scale factor
  • Easy setup and maintenance


  • Weight: 9 grams
  • Data accuracy: +/- 1% error margin
  • Battery life: 100+ riding hours on 2032 coin cell battery
  • Battery life (hours of use): up to 200 hours.

How does it work?

Choose the  Shimano left crank arm you want at checkout, and you’ll receive it with PRECISION installed. The crankset can be installed easily with the use of a Shimano crank installation tool, hex bits and a torque wrench. Install the 4iiii app, pair, update, calibrate and ride.


Software & Documentation

Display Compatibility


  • CatEye Cycling
  • Endomondo
  • Strava 
  • TrainerRoad
  • Wahoo Fitness: Workout Tracker 
  • Plus other apps supporting Bluetooth Smart/LE bike power devices

Android Apps

  • CateEye Cycling 
  • Endomondo
  • Strava 
  • Wahoo Fitness: Workout Tracker 
  • Plus other apps supporting Bluetooth Smart/LE bike power devices


  • Stealth evo+ 
  • Stealth 50 
  • Strada Smart
  • Padrone Smart 
  • Padrone Smart+


  • Edge 500 
  • Edge 510 
  • Edge 520 
  • Edge 800 
  • Edge 810 
  • Edge 820 
  • Edge 1000 
  • Edge Explore 1000 
  • epix 
  • Forerunner 310XT 
  • Forerunner 910XT 
  • Forerunner 920XT
  • fenix 2 
  • fenix 3 
  • fenix 3 HR


  • M450 
  • V800 BTLE 
  • Please note: the Polar V650 is not compatible


  • Ambit3 Sport (Bluetooth)
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