4iiii Precision 3 Power meter Deore XT M8100

In this article I will review the 4iiii Precision 3 Power Meter on the left Shimano Deore XT M8100 crankarm. I’ve purchased the factory installed crankarm and exchanged it on my Scott Scale 925 mountain bike. I’ll have a look at the key features, the 4iiii companion app for Google Android and my experience so far with the power meter (without the find my feature).

Key features 4iiii Precision 3 Power Meter for Shimano Deore XT m8100

While 4iiii has already a 3+ version out there from their Precision Power Meter series, I’ve opted for the Shimano Deore XT Precision 3 version (without the +) and thus without the Apple FindMy functionality (but upgradable would you be dying to get this feature set). If you are interested in a more in-depth comparison or findings on the double sided Pro version check out the in-depth review on DC Rainmaker.

On the left-side 4iiii Preceision 3 Powermeter product page you can read:

Whether you’re fighting for a Kona qualification spot, logging countless hours on virtual riding platforms or looking to better your time up the local KOM segment, you want accurate and reliable tools to unlock your potential. With up to 800 hours of battery life, +/-1% accuracy and backed by our industry-leading 3-year warranty, the PRECISION 3 Powermeter will be your trusted tool for years to come.


Not everyone has the perfect pedal stroke. With +/- 1% accuracy, 4iiii is the only crank-based power meter to use 3 strain gauges to measure all forces in your pedal stroke

Below you can see the fully spectrum of key features where the CR2032 Coin Cell is an important one for me. The Pioneer Dura Ace 9000 Single Leg Power Meter model SGY-PM910H and the 4iiii Viiiiva Heart Rate Monitor or the Wahoo Tickr-X all make use of the same CR2032 Coin Cell battery. So easier to perform maintenance having a single battery type powering it all.

Accuracy+/- 1%
Battery TypeCR2032 Coin Cell
Battery LifeUp to 800hrs
Waterproof RatingIPx7
Cadence Range30 – 170rpm
Power Range0 – 4,000W
Operating Temperature0 – 50°C
Communication ProtocolsANT+, Bluetooth

I really like the 800 hours of battery life which means that exchanging coin cell batteries is limited. The battery cap is designed in such a way that no tools are needed (in contrary to the PB Swiss Tools Coin Driver Stubby that is needed on the Pioneer power meter for Dura Ace 9000).

Very important on the mountain bike is the waterproofness and IPx7 rating. As you can read below the 4iii Precision 3 has perfectly survived the muddy, rainy winter and spring Netherlands (as well as my maintenance regime).

With a slim profile and just 9 grams added to the weight of a Shimano Deore XT crank arm, you have no need anymore to check for sufficient clearance between crank and frame.

Just for the fun I’ve tested the bridge function of the 4iiii Viiiiva Heart Rate monitor that can connect to Bluetooth and ANT+ devices and bridge the protocols. 🙂

4iiii Device Configuration App for Google Android and Apple iOS

The 4iiii Device Configuration App for Google Android comes with 3 major tabs to navigate the application on you smartphone:

  1. Devices
  2. Workout
  3. More

In the Devices tab you will see the 4iii devices that you’ve added. In my case the 4iiii Precision 3 power meter for Shimano Deore XT M8100 crankarm and the 4iiii Viiiiva Heart Rate monitor that I have been using for a while now as my primary heart rate monitor (with CORE Temperature Monitor attached to the strap).

From the individual device views you can check battery status, perform a zero offset (pre-ride calibration) or simply update firmware when needed/available. So this is the most used option for me personally.

In the Workout tab, you can record an activity like you would do on a smartwatch or cycling-computer. I have a Garmin Fenix 7, a Garmin Edge 840 or a Wahoo Elemnt Bolt to record workouts.

In the More tab most of the changes have happened since the review of the Viiiiva on the left and the more options on the right now, with the 4iiii Precision 3 power meter:

  • More
    • Profile
    • Saved Workouts
    • Workout Unit
    • Find
    • FAQ

  • More
    • Profile
    • Saved Workouts
    • Workout Unit
    • FAQ
    • Privacy Policy
    • Strava Options
    • Notifications

To use all the Strava Options you need to connect to your Strava Account. But this feature is aimed to auto uploading files to Strava (probably from the workout tab). The use case would be around running or cycling when you use your phone to record the workout activity. I’ll manage all of this in Garmin Connect or Wahoo Elemnt App (so on my cycling computer).

Notifications is another word for setting a switch to receive information about 4iiii products. In my case I’ve toggled the switch for the 4iiii Viiiiva and the Precision 3.

Precision 3 Power Meter on the single tracks

In practice the 4iiii Precision 3 power meter is robust and reliable power meter, that has survived the rainy and muddy “winter season”. It is a matter of calibrating the Precision 3 before the ride (zero offset function) and you can shred the single tracks.

The 4iiii Precision 3 power meter works well with the Wahoo Fitness Elemnt Bolt (stealth edition) and the Garmin Edge 840 cycling computers.

Installation is as easy as installing a Shimano Hollowtech II crank arm, which means two bolts, the Shimano Safety Plate (Y-1FU98120) and the Kogel Bearings pre-load cap that you need un-install and re-install. I would say maximum 10 minutes of work including the change of a pedal. Check out the review of the RISK cap removal tool, Park Tool BBT-10.2 Adjusting Cap tool.

Since I have the Scott Scale 925 mountain bike, the 4iii Precision 3 power meter is providing me accurate and reliable results when I’m on the go. No signs of wear during the maintenance efforts, and the Pro Bike Gear crank protectors and All Mountain Crank Defender will keep it safe from scratches as well.

Summarizing, the Precision 3 does what it needs to do, in a consistent way. 🙂

Concluding thoughts and wrap-up

The price-point of the 4iiii Precision 3 Power Meter build upon a Shimano Deore XT M8100 crank is around € 350,00 to € 375,00. While it is still a substantial amount of money it is not anywhere near the SRM Origin € 1800,00 mark.

The most important thing for me with such an investment is that it is a reliable and robust product that will survive the intended use out on the single tracks with rain, mud, dirt and cleaning with a garden hose. And to be fair the 4iiii Precision 3 Power Meter survives all that for months now.

When I’m in the race for a gravel bike I will certainly think about a crank-based power meter from 4iiii again, simply because it does what it needs to do in a very good way.

  • Do you use a power meter on your mountain bike or gravel bike ?
  • Do you use 4iiii products ? If so which ones ?

Interested in other product reviews on cycling-review.net click on any of the categories below:

Leave a Comment

Share to...