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4iiii PRECISION Shimano DURA-ACE 9100 Power Meter

Josh Matthew June 16, 2022
5.00 out of 5 based on 4 customer ratings
(4 customer reviews)


The 4iiii PRECISION is now available in Shimano’s latest evolution of the FC-R9100!

Clear selection

4iiii PRECISION Shimano DURA-ACE 9100 Power Meter

Shimano’s lightweight evolution of the FC-R9100 is now available as a 4iiii PRECISION power meter! Used by the World Tour teams Quick-Step Floors and Bora-hansgrohe, the 4iiii PRECISION Shimano DURA-ACE 9100 Power Meter is the lightest, most affordable direct force power meter available. The added weight of the 4iiii PRECISION is only 9 grams. Even better yet, it is accurate to within +/- 1.0%.

The 4iiii PRECISION is a left-only crank arm-based power meter and replaces your current left side crank arm. The 4iiii takes the power that is generated by your left leg and doubles it in order to determine your total power output. All PRECISION models run off a CR2032 battery, feature approximately 100 hours of battery life and support both ANT+ and Bluetooth SMART wireless protocols.


New 4iiii DA9100 PRECISION 3!

The all new 4iiii DA9100 PRECISION 3 Power Meter features the following improvements over the version 2:

  • 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.


4iiii PRECISION Shimano DURA-ACE 9100 Highlights

Highly Affordable

The 4iiii PRECISION DA9100 is one of the most affordable, ready to ride direct force power meters available.

High Level of Accuracy

The PRECISION is accurate to within +/- 1.0%. This compares to average accuracy of +/- 1.0-2.0% for most other power meters.

Lightest Power Meter

At only 9 grams of added weight, the PRECISION 3 is the lightest power meter you can buy!

Long Battery Life

The 4iiii PRECISION 3 DA9100 Power Meter provides and industry leading 800 hours of battery life!

Easy to Install

Installation is a breeze. Just swap it out for your current left-side crank arm and you’re ready to ride!

ANT+ & Bluetooth SMART

The power meter transmits data via both ANT+ and Bluetooth SMART so you can use it with a wide range of devices.


  • Versions: PRECISION 2 | PRECISION 3 (see above for PRECISION 3 differences)
  • 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


Crankset: This 4iiii power meter is compatible with Shimano DURA-ACE 9100 cranksets.

Please note, the power meter can also be installed other Shimano road cranksets, as long as they use Shimano's Hollowtech II interface. These cranksets can easily be identified by the two opposing pinch bolts that are used to secure the left side crank arm. Please see the image below and contact us if you have any questions on compatibility.Shimano Hollowtech II Left Crank Arm

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.

The clearance between the frame and left side power meter crank arm

4iiii PRECISION Shimano DURA-ACE 9100 Specs

Bike TypeRoad
Location of Power MeasurementCrank Arm
Left or Both Legs MeasuredLeft only
Independent Left/Right MeasurementNo
Crank Arm MaterialAluminum
Communication ProtocolANT+ and Bluetooth SMART
Claimed Accuracy+/- 1.0%
Automatic Temp. CompensationYes
Weight9 grams (added weight)
Battery TypeCR2032 coin cell
Battery LifeVersion 2: 100 hours / Version 3: 800 hours
Method of Cadence MeasurementAccelerometer
Warranty3 years

In the Box

  • 4iiii PRECISION Power Meter For Shimano DURA-ACE 9100
  • CR2032 coin cell battery
4 reviews for 4iiii PRECISION Shimano DURA-ACE 9100 Power Meter
  1. Joshua S (verified owner)

    Very impressed with this PM. I’ve been using crank based for close to a decade, but when I upgraded my bike, I decided to try a new system. Super easy to install. Great app used to keep firmware updated. Zero dropped connection on my first ride, which is a huge improvement! Would recommend every time.

    • Power Meter City

      Hi Joshua! Good job on your first ride. We are glad too that it worked perfectly fine on you as expected. We hope you continue to enjoy them and please let us know if there is anything else we can do!

  2. Mark (verified owner)

    Great product, fantastic price and ideal product to keep a super light race bike as it should be. Very consistent and minimalist. Just have to be careful of customs charge if buying from Europe!

    • Power Meter City

      Hi Mark. Thanks for this amazing review! Yes, most countries do have customs charges. We hope you continue to enjoy your power meter and we are here if there is anything else we can do!

  3. cjharrer (verified owner)

    I wanted a Power Meter, but I’m also on a budget. This product was by far the easiest upgrade I’ve ever done to my bike! Pulled the left crank-arm, put a new CR-2032 battery in, installed crank arm and pedal, updated firmware, calibrated and off and riding. Pairing to my cyclometer was simple and the output matches what I get on my trainer. Definitely a good investment for me and I will incorporate into my training plan!

    • Power Meter City

      Hi Cjharrer. Thanks for this kind review on your 4iiii DURA-ACE 9100. We hope you continue to enjoy them and please let us know if there is anything else we can do!

  4. cendres (verified owner)

    Dollar for dollar, I think this is the best single-sided PM going for those on a budget. It’s been 100% reliable in all sorts of messy conditions and has proven to match up very well with power numbers from my Kickr. PM City shipping was super quick and pricing was very fair. Will be a repeat customer.

    • Power Meter City

      Hi Cendres. Thanks for the review! Not only are you getting accurate, consistent data…but you got a DURA-ACE 9100 crank arm to boot – not too shabby 🙂 We hope you continue to enjoy it.

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