4iiii PRECISION Shimano XTR M9100 Power MeterSeptember 25, 2023
$399.99 – $529.99
4iiii power for your Shimano’s XTR M9100 or M9120 crankset!
4iiii PRECISION Shimano XTR M9100 Power Meter
The 4iiii PRECISION Shimano XTR M9100 Power Meter is brings power to your M9100 or M9120 crankset. The 4iiii PRECISION power meter is a left-only crank arm-based power meter and replaces your current left side crank arm. It takes the power that is generated by your left leg and doubles it in order to determine your total power output.
Using 3D power meter technology capable of measuring tri-axial strain, the 4iiii XTR M9100 Power Meter is accurate to +/- 1.0%. In addition, it’s very lightweight, adding only 9 grams of weight to your crankset.
It features 800 hours of battery life and is compatible with both ANT+ and Bluetooth SMART devices. This means it’s compatible with your favorite bike computer, smart phone or tablet.
Key Product Details
This power meter is compatible with XTR M9100/9120/9130 cranksets. It is also compatible with all other Shimano x100/x120/x130 series MTB cranksets such as the XT M8100/M8120/M8130 or the SLX M7100/7120/7130. See Compatibility tab for more information.
This 4iiii power meter measures left leg power and doubles the value to account for both legs (assumes both legs are generating the same force).
New 4iiii XTR M9100 PRECISION 3+!
The all new 4iiii XTR M9100 PRECISION 3+ power meter features the following improvements over the version 2:
- Apple Find My which allows you to always know where your bike is!
- 800 hours of battery life – the longest coin cell battery life in a power meter on the market!
- Sleeker, slimmer profile making most incompatibility issues a thing of the past.
- Stronger antenna for even better connectivity.
- Indicator light for battery life, successful zero-offset and when the unit has been turned on.
Affordable, accurate to within +/- 1.0%, lightweight at only 9 grams of added weight, 800 hours of battery life (PRECISION 3+), CR2032 user-replaceable battery, ANT+ and Bluetooth compatible, easy to install, 3-year warranty. See Specs tab for more information.
Advice From Our Staff:
4iiii left side crank arms are some of our best-selling units. They are affordable and easy to install. The one consideration is they only measure left leg power compared to some other power meters that measure power from both legs (those versions usually cost more however).
Options For This Power Meter
- Versions: PRECISION 2 | PRECISION 3+ (see above for PRECISION 3+ differences)
- Crank arm lengths: 170 mm | 175 mm
Other Versions to Consider
Dual-Sided XTR 9100/9120 Crankset: We also sell the 4iiii PRECISION PRO Shimano XTR 9100/9120 Dual-Sided Power Meter which is a complete crankset. It is more expensive, however it measures power from both legs.
Crankset: The 4iiii power meter is compatible with XTR M9100/9120/9130 cranksets. It is also compatible with all other Shimano x100/x120/x130 series MTB cranksets such as the XT M8100/M8120/M8130 or the SLX M7100/7120/7130.
It is not compatible with x000 series cranks such as the XTR M9000, XT M8000 or SLX M7000.
Check Frame Clearance: Crank-arm based power meters 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 for the PRECISION 2 and 8 mm of clearance for the PRECISION 3+. Also, make sure 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 your clearance is close but not quite sufficient, what many people will do is simply install a 1 or 2 mm bottom bracket spacer (between the left crank arm and the frame). This should provide you with the clearance you need.
4iiii PRECISION Shimano XTR M9100 Specs
|Name||4iiii PRECISION XTR M9100|
|Location of Power Measurement||Crank Arm|
|Left or Both Legs Measured||Left only|
|Independent Left/Right Measurement||No|
|Crank Arm Material||Aluminum|
|Communication Protocol||ANT+ and Bluetooth SMART|
|Claimed Accuracy||+/- 1.0%|
|Automatic Temp. Compensation||Yes|
|Weight||9 grams (added weight)|
|Battery Type||CR2032 coin cell|
|Battery Life||Version 2: 100 hours / Version 3+: 800 hours|
|Method of Cadence Measurement||Accelerometer|
In the Box
- 4iiii PRECISION Power Meter
- CR2032 coin cell battery
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.
- 8 mm Allen key
Common Questions and Answers
Question: What is the difference between the 4iiii PRECISION 2 and PRECISION 3+?
- The P3+ was introduced in early 2022 and offers several benefits over the P2 model. Please see our article for more information: 4iiii PRECISION 2 vs. PRECISION 3+ Comparison.
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.