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4iiii PRECISION Shimano Ultegra R8000 Power Meter

Josh Matthew January 25, 2022
4.97 out of 5 based on 29 customer ratings
(29 customer reviews)

$299.99

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.

 

4iiii R8000 Power Meter Highlights

Most Affordable DFPM

The 4iiii PRECISION 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 is the lightest power meter you can buy!

Easy to Install

Installation is a breeze. Just swap it out for your current left-side crank arm and you’re ready to ride! Installation takes minutes…not hours.

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

The power meter is available in the following crank arm lengths: 165 mm | 170 mm | 172.5 mm | 175 mm

 

Tools Needed for Installation

The following tools are typically required 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 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.

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 Life100 hours
Method of Cadence MeasurementAccelerometer
Warranty3 years

In the Box

  • 4iiii PRECISION Shimano Ultegra R8000 Power Meter
  • CR2032 coin cell battery
  • Quick Start guide
29 reviews for 4iiii PRECISION Shimano Ultegra R8000 Power Meter
  1. Rodrigo Muñiz (verified owner)

    Excellent, I installed it on my CH2 Tere without any problem. It synchronises very well with my garmin edge 530.
    I have doubts about the battery door, I am a little nervous that it can open mid-ride, hopefully not.

    • Power Meter City

      Hi Rodrigo, Thank you for this kind review on your new 4iiii PRECISION Shimano Ultegra R8000 Power Meter – we hope you will continue to enjoy them. Good luck on your rides and please let us know if there is anything else we can do!

  2. Jim Brewer (verified owner)

    Thanks PMC for the prompt handling and shipping of my 4iii power meter. I was using a heart rate monitor, but with the power meter I find myself not only enjoying looking at all of the data during and post ride, but pushing harder because I can now see what is actually occurring. The zero offset is simple as is setup. Thanks again, Jim

    • Power Meter City

      Glad we helped you find a solution Jim and thank you for taking your time to leave us an awesome review! We are here if there is anything else we can do! Ride safe!

  3. Carlos Silva (verified owner)

    Very happy with my 4iiii, so far so good, the customer service from PMC has no rival they were able to accommodate all of my requests. Thank you guys once again!

    • Power Meter City

      Thank you for this Carlos – we also want to thank you for being a great customer! We hope you will enjoy your new power meter! Let us know if there is anything else we can do! Ride safe!

  4. Stacker (verified owner)

    PMC is as great outfit to work with. Packing, shipping and support all exceed expectations. I now have two 4iiii left side crank arms. Both have significant miles in all conditions. Both perform excellent and I have no concerns/complaints with my purchase.

    • Power Meter City

      Thanks for this Stacker – we really appreciate it! We are glad you liked your new 4iiii PRECISION Shimano Ultegra R8000 Power Meter. If there is anything else we can do, please let us know! Ride safe!

  5. Sean (verified owner)

    This is a game changer. Having the power information while riding helps immensely with managing training load and conserving energy on longer rides. Installation was easy and just took about five minutes. (Be sure you have a torque wrench.) Power Meter City provided a great level of service, which I found about perfect for an internet merchant.

    • Power Meter City

      Thanks for this awesome review Sean – We hope you will enjoy your new power meter! Please let us know if there is anything else we can do to help. Ride safe!

  6. Tony (verified owner)

    I was concerned I would not receive the latest 4iiii power meter. I sent an email and Josh responded promptly. He assured me that I would receive only the latest device, which really put my mind at ease and an end to my search. My 4iiii power meter arrived quickly and with a follow up from Power Meter City about any concerns of which they were none. THANK YOU SO MUCH PMC!

    • Power Meter City

      Thanks for this kind review Tony. We are glad you finally have your new power meter – we hope you will enjoy them. Please let us know if there is anything else we can do!

  7. Tom S (verified owner)

    The 4iiii template indicated the PM might be a close fit to the chain stay but all went well with several mm to spare. Installation was a snap and the PM paired immediately to both the 4iiii android app and the Garmin head unit. Now I have power on both my smart trainer bike and my outside ride. Sweet.

    • Power Meter City

      Great! Thanks for letting us know Tom. We hope you will continue to enjoy new power meter! Let us know if there is anything else we can do! Ride safe!

  8. Jeramie Thompson (verified owner)

    After researching several different options, I decided to go with the 4iii and couldn’t be more happier and impressed with this power meter. The package shipped quickly and arrived unharmed. The crank was an easy install and paired with my Garmin 520 perfectly. Been on several rides with it and I’m impressed with how easy it is to use and works with my computer. Thanks Power Meter City!

    • Power Meter City

      Looks like you are enjoying them – good luck on your rides Jeramie. Please let us know if there is anything else we can do! Ride safe!

  9. Mal (verified owner)

    Foremost the 4iiii PM arrived on the other side of our planet in a timely fashion and it was nice to see it was appropriately packaged.
    As a previous post has commented, my Canyon Endurace chainstay didn’t allow this crank to fit (only by a cats whisker) but this was quickly remedied with a spacer with no issues. From there setup was achieved in no time. Josh from PMC responded to my emails in a friendly and professional manner.
    I’m very pleased with both product and service.

    • Power Meter City

      Hi Mal. Thank you for this kind review! We hope you will enjoy your new power meter. Good luck on your rides and we are here if there is anything else we can do!

  10. 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!

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