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4iiii PRECISION Shimano Ultegra R8000 Power Meter

Josh Matthew May 23, 2022
4.93 out of 5 based on 30 customer ratings
(30 customer reviews)

$334.99$384.99

4iiii’s PRECISION power meter combined with Shimano’s Ultegra R8000 groupset

Clear selection

4iiii PRECISION Shimano Ultegra R8000 Power Meter

Introducing the all new 4iiii PRECISION Shimano Ultegra R8000 Power Meter. 4iiii has combined their patent pending 3-D tri-axial strain gauge technology, measured at +/- 1.0% accuracy, with Shimano’s best of breed Ultegra R8000 groupset. The result is one of the lightest, most affordable and most accurate direct force power meters available.

The PRECISION determines your total power based on the force that is generated by your left leg. This left-only design allows for a power meter that is lightweight and easy to install. Specifically, the power meter adds only 9 grams to your crank arm and is installed in about 10 minutes. In addition, the PRECISION is compatible with both ANT+ and Bluetooth SMART devices. This means you can use it with your favorite bicycle computer, watch or smart phone.

 

New 4iiii R8000 PRECISION 3!

The all new 4iiii R8000 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 R8000 Power Meter Highlights

Highly Affordable

The 4iiii PRECISION R8000 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 R8000 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.

Options

  • 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

Compatibility

Crankset: This 4iiii power meter is compatible with Shimano R8000 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 Ultegra R8000 Specs

Name4iiii PRECISION Ultegra R8000
Bike TypeRoad
Location of Power MeasurementCrank Arm
Left or Both Legs MeasuredLeft only
Independent Left/Right MeasurementNo
InstallationEasier
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 Shimano Ultegra R8000 Power Meter
  • CR2032 coin cell battery
30 reviews for 4iiii PRECISION Shimano Ultegra R8000 Power Meter
  1. Ron (verified owner)

    Impressive delivery speed, expected to be delay due to COVID-19 pandemic, but end up received earlier than expected. Good product, good price, finally with a power meter without burning a big hole on my pocket..thx powermetercity:)

    • Power Meter City

      Hi Ron. We really appreciate this! Thank you for being a great customer too. We are here if there is anything else we can do!

  2. gaston2010 (verified owner)

    Amazing power meter.
    Great results riding your bike, it’s perfect for jumping into the power meter metric to control your performance.
    You will be able to get faster and doses your power.

    • Power Meter City

      Thanks for this Gaston. We hope you will continue to enjoy your 4iiii PRECISION Shimano Ultegra R8000 Power Meter. We are here if there is anything else we can do!

  3. Cullen M (verified owner)

    Quick and easy delivery from PM, works well! Make sure to order the Shimano crank tool.

    • Power Meter City

      Hi Cullen. Thanks for this kind review! We hope you will continue to enjoy your new 4iiii PRECISION Shimano Ultegra R8000 Power Meter. We are here if there is anything else we can do!

  4. STEPHEN ESMACHER

    Power Meter City (PMC) is great to do business with. Before ordering the Ride Ready – Left Side version I reached out to 4iiii and there was a little confusion about whether there would be sufficient chain stay clearance on my Canyon Endurace. They said it would so I ordered one from PMC but it didn’t have sufficient clearance. PMC took it back and gave me a full refund. I hope I have a need to do business with them again.

    • Power Meter City

      Hi Stephen. Thanks for this. Let us know if there is anything else we can help you with!

  5. Marcos Pereira (verified owner)

    Easy to install, light and good price!

    • Power Meter City

      Hi Marcos. Thanks for this kind review! Let us know if there is anything else we can help you with!

  6. Adam Phillips (verified owner)

    This thing is awesome!! I have been riding for a little over 22 years with a few years of racing. I had a power meter years ago, back before things was this simple. I can’t believe how easy and affordable this 4iiii is. Only takes a few minutes to put on and works perfectly out of the box. Plus you get cadence as well. It will not give you individual leg watts unless you buy the dual, but for me I don’t need that. Not a lot of difference between my two legs and no matter what I do can’t seam to change that. The single arm doubles you out put at the crank and gives a very accurate reading. Also like getting the reading at the crank not the wheel so I can see what I’m doing not the loss of drive chain and wheel. Great product great place to buy from as they are on top of their game. It got shipped out right away. I have no doubts that the customer service is out standing although I have never had to use it. If you want to get better at cycling, power out put is the best information tool you can have and at this price its very affordable

    • Power Meter City

      Hi Adam. You’re right! This 4iiii PRECISION Shimano Ultegra R8000 Power Meter really works great! Thank you for this awesome review! We hope you will continue to enjoy them and please let us know if there is anything else we can help you with!

  7. Dave Fishman (verified owner)

    Love the power meter has opened up a different way to train. And train more accurately. Power Meter City delivers great service at an affordable price. Was going to purchase earlier but they were out of stock. Had them add me to email list when available. Got notified purchased the meter and was delivered on time. Thanks for the great service.

    • Power Meter City

      Hi Dave. Looks like you are enjoying your new 4iiii PRECISION Shimano Ultegra R8000 Power Meter. We want to thank you for being a great customer! Let us know if there is anything else we can help you with!

  8. Fazlee

    Excellent product! Flawless pairing to my Garmin Edge 530 and Forerunner 945. Comes packaged very nicely. I don’t use the 4iiii app for much, but for updating the firmware of the power meter, it worked effortlessly on the first try. Power meter installs easily of course, just the standard 2 bolt interface for Hollowtech II cranksets.

    The item was shipped out the same day I placed the order (maybe even within the hour!) and I received it a week later (thanks pandemic + elections shutting down the local mail office).

    Happy purchase, happy result, and I will definitely return here the next time I purchase a power meter (which will likely be soon now that my wife has seen what this does…)

    • Power Meter City

      Hi Fazlee. Looks like you are enjoy your new 4iiii power meter! Good choice BTW. Good luck on your future rides and we are here if there is anything else we can do.

  9. joel mclarry (verified owner)

    Power meter works great with wahoo bolt. No issues, power drops or spikes. Very easy install that took 5 minutes.

    • Power Meter City

      Hi Joel. Thanks for leaving a great review on your 4iiii PRECISION Shimano Ultegra R8000 Power Meter. We hope you continue to enjoy them and we are here if there is anything else we can do!

  10. Chuck P (verified owner)

    Doing a new build and since I have a 4iiii Precision power meter on my other bike (b-day present last year) that has been flawless, why fix what ain’t broke? Very fast shipping from Power Meter City. Easy peasy installation and pairing to my head unit (Wahoo ROAM with associated iPhone app). The only learning curve was figuring out you can’t pair two power meters at the same time on the 4iiii app. Minor inconvenience, but not a big deal. But it does mean having to unpair one power meter and re-pair the other whenever I switch riding bikes. Otherwise, the 4iiii Precision power meter works as advertised, i.e., it tells me how much I suck. 🙂

    • Power Meter City

      Hi Chuck. Thanks for this! Good choice BTW. We hope you continue to enjoy your new 4iiii PRECISION Shimano Ultegra R8000 Power Meter. We are here if there is anything else we can help you with!

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