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4iiii PRECISION Shimano GRX RX810 Power Meter

Niel Ubod May 17, 2022
5.00 out of 5 based on 9 customer ratings
(9 customer reviews)

$334.99$384.99

4iiii’s PRECISION power meter combined with Shimano’s GRX RX810 groupset

Clear selection

4iiii PRECISION Shimano GRX RX810 Power Meter

Introducing the all new 4iiii PRECISION Shimano GRX RX810 Power Meter. 4iiii has combined their patent pending 3-D tri-axial strain gauge technology, measured at +/- 1.0% accuracy, with Shimano’s GRX RX810 groupset. The result is one of the lightest, most affordable and most accurate direct force power meters available for gravel and adventure riders.

The 4iiii power meter measures left leg power and doubles this value to determine your total power. This left-only design allows for a power meter that is affordable, lightweight and easy to install. 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 GRX RX810 PRECISION 3!

The all new 4iiii GRX RX810 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.

 

Highlights

Highly Affordable

The 4iiii PRECISION GRX RX810 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 GRX RX81 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: 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: The 4iiii power meter is compatible with all Shimano GRX cranksets including GRX RX600.

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 GRX RX810 Specs

Name4iiii PRECISION 3 GRX RX810
Bike TypeGravel
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 GRX RX810 Power Meter
  • CR2032 coin cell battery
9 reviews for 4iiii PRECISION Shimano GRX RX810 Power Meter
  1. Andrew littleton (verified owner)

    Power meter meter shipped same day, and product was was as advertised.

    • Power Meter City

      Thank you, Andrew! We really appreciate it! If there is anything else we can do, please let us know! Ride safe!

  2. David Williams (verified owner)

    The power meter works flawlessly and was simple to install. The service and delivery from Power Meter City was exceptional. Less than a week to deliver to Brisbane, Australia.

    • Power Meter City

      Awesome David! That was fast than expected! We hope you will enjoy your new power meter. We are here if there is anything else we can help you with!

  3. Kim Hyunseung (verified owner)

    My second PM I bought here and I am very satisfied. Works well, perfectly fits with my Giant Revolt. Thanks for caring, have a nice day!

    • Power Meter City

      Thank you for the loyalty and kind review Kim – we really appreciate it! We hope you will enjoy your 2nd power meter (Good choice BTW!) Let us know if there is anything else we can do! Ride safe!

  4. Takaaki Takuma (verified owner)

    This is the third Power Meter by me. One STAGES and two 4iiii. 4iiii is awesome PM. High stability and accuracy, water registance. If I buy one more PM again, absolutely will chose 4iiii.
    Power Meter City is reliable shop, because quick shipping and send me emails when I need.

    • Power Meter City

      Hi Takaaki. Thanks for this kind review – we really appreciate it. We hope you will continue to enjoy your new power meter. Please let us know if there is anything else we can do!

  5. Trevor (verified owner)

    As all the other reviews say… great customer service. Arrived within a week in Australia, faster than what local post could achieve….
    Easy to install, calibrate and start using. Great communication from ordering, shipping through to delivery… and excellent support followup as well.
    Definitely recommend purchasing from Power Meter City!

    • Power Meter City

      Hi Trevor. Thanks for this kind review! We are glad you finally have your power meter – good luck on your future rides. We are here if there is anything else we can do!

  6. Nerio (verified owner)

    Excellent product, and superb customer service from Powermetercity. Arrived within 3 business days (earlier than expected) even despite shipping all the way to Singapore during the current pandemic.

    Purchasing this has been a hassle free experience, and all my questions were answered promptly by using the chat feature on the site. Furthermore, Powermetercity is the only place which had this in stock.

    Lastly, the product itself has been faultless. Works really well, great app support, and does the job!

    • Power Meter City

      Nice! Thanks for this Nerio. We are glad it came fast despite the current situation. Good luck on your future rides! We are here if there is anything else we can do!

  7. Thomas Coleman (verified owner)

    Good price and good quality equipment

    • Power Meter City

      Hi Thomas. Thanks for this awesome review on your 4iiii PRECISION Shimano GRX RX810 Power Meter. We hope you will continue to enjoy them and we are here if there is anything else we can do!

  8. Philip Gray (verified owner)

    This was my first purchase from Power Meter City and I was not disappointed! Super fast shipping, I was installing the power meter to my bike in less than a week after purchase, which is pretty good as I am in New Zealand. Great communication and follow up emails offering post purchase support, if only more companies offered this level of customer care!

    • Power Meter City

      Hi Philip. Thanks for this kind review on your 4iiii PRECISION Shimano GRX RX810 Power Meter. Good choice for your first power meter! We hope you will continue to enjoy them! We also want to thank you for being a great customer! Let us know if there is anything else we can do!

  9. Michael Brannon

    This is my 2nd 4iiii power meter purchased from power meter city. I had a problem with this model, and Josh from pmc shipped me a new one out, pronto! PMC has the best customer service that I’ve dealt with recently. I’ll definitely be purchasing all my power meters from Power Meter City

    • Power Meter City

      Hi Michael. We really appreciate this and thank you for being a great customer. We hope you will enjoy your new 4iiii PRECISION Shimano GRX RX810 Power Meter. Please let us know if there is anything else we can do!

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