4iiii PRECISION PRO Shimano Ultegra R8000 Dual-Sided CranksetJosh Matthew May 16, 2022
4iiii’s 3-D tri-axial strain gauge technology, dual-sided power and +/- 1.5% accuracy
4iiii PRECISION PRO Shimano Ultegra R8000 Dual-Sided Crankset
The 4iiii PRECISION PRO Shimano Ultegra R8000 Dual-Sided Crankset combines 4iiii’s patent pending 3-D tri-axial strain gauge technology with Shimano’s best-selling Ultegra R8000 crank. The result is an accurate, lightweight and highly reliable power meter crankset that is capable of tacking the most grueling workouts or races.
The dual-sided 4iiii R8000 power meter crankset also features independent left/right power measurement. With a power sensor located on the inside of both crank arms, the power meter can measure the forces generated by each leg individually.
The 4iiii is also extremely lightweight, adding approximately 20 grams to the Shimano R8000 crankset. The power meter is compatible with both ANT+ and Bluetooth SMART devices and is accurate to +/- 1.0%.
4iiii R8000 Dual-Sided Power Meter Options
- Chainrings: 50/34 | 52/36 | 53/39
- Crank arm lengths: 165 mm | 170 mm | 172.5 mm | 175 mm
Tools Needed for Installation
You will need the following tools for installation of this product. You can purchase many of these commonly used tools in our store.
- Shimano Crank Arm Cap Tool
- 5 mm Allen key
Bottom Bracket: This power meter uses a 24 mm Shimano road spindle and must be used with a 24 mm Shimano bottom bracket.
Tip - If you already have a Shimano crankset on your bike, then this power meter will fit your bottom bracket perfectly as all Shimano cranksets use a 24 mm spindle.
Check Frame Clearance: Crank-arm based power meters like this one attach a sensor on the inside of the left crank arm. On some bikes, there is not enough room between the left crank arm and the chainstay for the sensor to clear the frame. Therefore, you should make sure you have at least 10 mm of clearance between the left crank arm and the chainstay - and that you don't have a bottom bracket mounted rear brake (used on some aero and TT bikes). The important area to measure is right in the middle of the crank arm. Please refer to the image below.
If you find that you have around 7-9 mm of clearance, what many people will do is simply install a 1 or 2 mm bottom bracket spacer (between the left crank arm and the frame), which will give them the clearance they need.
4iiii PRECISION PRO Shimano Ultegra R8000 Power Meter Specs
|Name||4iiii PRECISION 2 PRO R8000|
|Location of Power Measurement||Crank arm|
|Left or Both Legs Measured||Both|
|Independent Left/Right Measurement||Yes|
|Installation||More involved (60 min. estimated)|
|Crank Arm Material||Aluminum|
|Communication Protocol||ANT+ and Bluetooth SMART|
|Claimed Accuracy||+/- 1.0%|
|Active Temperature Compensation||Yes|
|Weight||694 grams (170 mm, 50-34T)|
|Battery Life||100 hours|
|Method of Cadence Measurement||Accelerometer|
|BCD||110 4-bolt asymmetric|
|Spindle Size||24 mm|
In the Box
- 4iiii Dual-Sided Power Meter Crankset
- 2 CR2032 coin cell batteries