4iiii PRECISION PRO Shimano Ultegra R8000 Dual-Sided CranksetOctober 17, 2023
4iiii’s 3-D tri-axial strain gauge technology, dual-sided power and +/- 1.0% 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%.
Key Product Details
This power meter is compatible with 2×11 road drivetrains and 24 mm Shimano bottom brackets. Most customers that buy it already have a Shimano R8000 crankset on their bike and therefore, it’s an easy swap. However, it can be used on any road bike as long as its 2×11 with a 24 mm bottom bracket. See Compatibility tab for more information.
This 4iiii power meter has a power sensor on both crank arms and measures power from both legs. It is also able to measure your left vs. right leg power.
Dual-leg power measurement, can measure left vs. right leg power, accurate to within +/- 1.0%, lightweight at only 20 grams of added weight, 100 hours of battery life, CR2032 user-replaceable battery, ANT+ and Bluetooth compatible, 3-year warranty. See Specs tab for more information.
Advice From Our Staff:
This is a great option for customers with a Shimano R8000 drivetrain that want to keep an OEM R8000 crankset on their bike but add power. We also like that fact that this crankset measures power from both legs and has a 3-year warranty, which is longer than most power meters.
Options For This Power Meter
- Chainrings: 50/34 | 52/36 | 53/39
- Crank arm lengths: 170 mm | 172.5 mm | 175 mm
Other Versions to Consider
Left Side R8000: We also sell the 4iiii PRECISION Shimano Ultegra R8000 Power Meter which is a left side crank arm only. It is more affordable, however it only measures left leg power.
Bottom Bracket: This power meter is compatible with 2x11 road drivetrains and 24 mm Shimano bottom brackets. Most customers that buy it already have a Shimano R8000 crankset on their bike and therefore, it's an easy swap. However, it can be used on any road bike as long as its 2x11 with a 24 mm bottom bracket.
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|
|Q Factor||146 mm|
In the Box
- 4iiii Dual-Sided Power Meter Crankset
- 2 CR2032 coin cell batteries
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
Common Questions and Answers
Question: How do I determine what length my current cranks are so I can make sure I get the same size?
- Your crank arm length should be printed or stamped on the inside of the left crank arm, usually near the pedal end.