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4iiii PRECISION Power Meter For Shimano Ultegra 6800

Josh Matthew September 24, 2019
4.93 out of 5 based on 15 customer ratings
(15 customer reviews)

$449.99 $329.99

The lightest, most affordable, ready to ride direct force power meter available!

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4iiii PRECISION Power Meter For Shimano Ultegra 6800

Used by World Pro teams Quick-Step Cycling and BORA – hansgrohe, the 4iiii PRECISION Power Meter for Shimano Ultegra 6800 is the lightest, most affordable direct force power meter available. The 4iiii PRECISION power meter is accurate to within +/- 1.0%. In addition, it adds a mere 9 grams of weight to your crank arm. The 4iiii is a left side crank arm-based power meter and takes the power that is generated by your left leg and doubles it in order to determine your total power output.

In addition to being affordable, lightweight and highly accurate, the 4iiii PRECISION measures precise cadence data, has 3D power meter technology capable of measuring tri-axial strain and is compatible with both ANT+ and Bluetooth SMART devices.



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



The 4iiii power meter is compatible with all Shimano Hollowtech II road cranks. Please contact us if you have questions on compatibility.


In the Box

  • 4iiii Power Meter
  • 2 2032 coin cell batteries
  • Quick Start guide


4iiii PRECISION Shimano Ultegra 6800 Specs

Name4iiii PRECISION Ultegra 6800
Bike TypeRoad
Location of Power MeasurementCrank Arm
Left or Both Legs MeasuredLeft only
Independent Left/Right MeasurementNo
Communication ProtocolANT+ and Bluetooth SMART
Claimed Accuracy+/- 1.0%
Weight9 grams (added weight)
Battery TypeCR2032 coin cell
Battery Life100 hours
Method of Cadence MeasurementAccelerometer
Warranty1 year


15 reviews for 4iiii PRECISION Power Meter For Shimano Ultegra 6800

  1. Avatar

    Ivan Murdock (verified owner)

    Reliable and repeatable. This is a great product.

    • Power Meter City

      Power Meter City

      Hi Ivan, That’s what we like to hear! Enjoy it!

  2. Avatar

    Doug (verified owner)

    I have used the 4iii power meter for just over a month now. I have been very happy with its ease of setup, price and accuracy. Now back to interval training!

    • Power Meter City

      Power Meter City

      Hi Doug, Thanks for the review and go crush those intervals! We’re here if you need anything.

  3. Avatar

    ari (verified owner)

    Bought this product when I visited US for a week, powermetercity delivered it fast without any trouble.
    the 4iiii itself has been great so far (2 weeks usage with some rain included), though it is left side only PM, the reading is comparable with my old garmin vector (dual side power meter) where they mostly resulted in single digit watts difference of average power and more importantly, it is consistent enough (though, I have not test it on high enough elevation/mountain). Now, I mostly use the 4iiii only, this way I can switch to lighter pedal and get rid of the Vector pods.

    • Power Meter City

      Power Meter City

      Hi Ari, Great to hear the 4iiii PRECISION Ultegra power meter is working out for you. It really is a great power meter and we too have found them to be super reliable and consistent. Enjoy it and let us know if you need anything else.

  4. Avatar

    Mohd Herwan (verified owner)

    Great product. Have been used more than a month, working really great

    • Power Meter City

      Power Meter City

      Hi Mohd. Thanks for the review. The 4iiii crank arms are some of our most popular units. I’m glad it’s working out for you!

  5. Avatar

    Bryan (verified owner)

    Have been using my 4iiii Precision PM for three months now, through all sorts of late fall and wet winter riding and so far it’s been flawless. This was my first purchase from Power Meter City and I was very happy with the speed of order fulfillment and shipping. Will definitely be looking at 4iiii and PMC for my next purchase!

    • Power Meter City

      Power Meter City

      Hi Bryan. Thanks for the review. I’m happy to hear your 4iiii power meter is delivering the goods! Keep up the good work and let us know if there is anything else we can help you with!

  6. Avatar

    Brett Chapman (verified owner)

    Bought from PMCity while visiting the US from New Zealand back in October 2018. I have a Stages power meter (1st Gen) which has worked fine apart from having to remove the battery each ride but couldn’t go past the 4iiii for price. I have to say that it has worked flawlessly for me and I can only speak positively about its reliability and performance from day 1. My Stages has been relegated to my training bike.

    • Power Meter City

      Power Meter City

      Hi Brett. Thanks for the review. Glad to hear the 4iiii 6800 is working well for you. Come back and visit us anytime!

  7. Avatar

    sakari uunila (verified owner)

    excellent product. some trouble synching with Polar bike computers, which are compatible, but other than that, it is working very well. Using it with my polar v800 watch also and works well. Would highly recommend.

    • Power Meter City

      Power Meter City

      Hi Sakari. Thanks for leaving us a review on your 4iiii PRECISION Shimano Ultegra 6800. Keep up the good work!

  8. Avatar

    Alexander Ortiz (verified owner)

    After a few month of riding the 4IIII PRECISION POWER METER FOR SHIMANO ULTEGRA 6800 has been working reliably and consistently giving me great power numbers. Battery life is excellent. I had an issue with Cadence numbers spiking every now and again so I reached out to the customer support. Wriley reached out to me and addressed every concern I had including an analysis of my ride through fit files.I can’t complain about the support. It’s great when a product manufacture is responsive and helpful and works with it’s customer.

    • Power Meter City

      Power Meter City

      Hi Alexander. Thanks for the great review of your 4iiii. We’re glad you got everything sorted and hope you continue to enjoy it. Please let us know if there is anything else we can do!

  9. Avatar

    banjeman (verified owner)

    just received and installed power meter (took about 5 minutes). Power meter city was great to work with and shipping was fast 2-days. I initially ordered the podiiiium; however before shipping power meter sent me an email asking to confirm it would work with my bike and based on directions they sent me I had serious concerns, so they refunded my money. I spent the next 4-5 hours researching power meter left crank arms and if they would fit on a 2015 TREK Emonda SLR frame. My research confirmed Stages Gen. 3 worked, but not much found regarding 4iiii. I noted the pictures and realized the Precision was more in the middle of the crank than the podiiiium, so I took the chance and ordered the precision. To hedge my bet I also ordered 24mm round 0.5mm thick shims designed for shimano BB. Needless to say I did not need the shims. I took a picture of the clearance (~2mm), but apparently on this website reviewers can’t post pictures. I just want anyone who is concerned about a 4iiii precision left crank power meter fitting on a TREK Emonda SLR frame the answer is a resounding YES! I can’t attest to the longevity of this device yet, but the interaction with power meter city was 5 stars for sure.

    • Power Meter City

      Power Meter City

      Hi Ben. Thanks for the great review and we are glad we could help you out. We hope you enjoy your 4iiii power meter and are here if you need anything else.

  10. Avatar

    Gianluca Catignani (verified owner)

    Bought this product recently while in USA, and needed it for my second bike which mounts Shimano Ultegra crankset, Powermetercity delivered it fast and I am very happy with customer service of Powermetercity, which replied my questions.
    The 4iiii is working just fine, and giving consistent figures (4 weeks usage ), and since it is left side only PM, I can dismount it and mount it on my first bike I use for racing,, as both my bikes mount Shimano Ultegra. Thumbs Up for Pewermetercity.

    • Power Meter City

      Power Meter City

      Hi Gianluca. Thanks for taking a moment to leave a review on your 4iiii, we really appreciate it. Keep up the good work on the bike!

  11. Avatar

    Leon Shen (verified owner)

    Excellent! Reliable! This is a must have to help with training. I have 4iii on one bike, and Stages on another. Their readings are very comparable and consistent. A side benefit is that the investment on these power meters help hold me on my current bikes for more years – big savings. The shipment from Powermetercity is very fast!

    • Power Meter City

      Power Meter City

      Hi Leon. Thanks for the review and we’re pumped to hear these power meters are working out for you! Let us know if there is anything else we can do.

  12. Avatar

    Bruce Tangney

    Fits great on the Domane 5.2, plenty of clearance. Thanks for your help Josh!

    • Power Meter City

      Power Meter City

      Hi Bruce. Thanks for the review. It was our pleasure to help you out!

  13. Avatar

    Mike Ballein (verified owner)

    4iii crank arm power meter works great. Power meter city service is outstanding. Quick turnaround delivery. They are my go to now, I have purchased many different products and they are consistently outstanding. Great job PMC! Thank you Mike

    • Power Meter City

      Power Meter City

      Hi Mike. Thanks for the review. I am glad we could help you out and we hope you enjoy your 4iiii!

  14. Avatar

    David (verified owner)

    Great product. Easy to set up and update firmware. Accurate every time. Replaced my older Stages with this one!

    • Power Meter City

      Power Meter City

      Hi David. Thanks for the review on your 4iiii. We’re glad you are enjoying it and are here if there is anything else we can help you with!

  15. Avatar

    Hans Bagger (verified owner)

    My first ever power meter! It was so easy to set up, use and provides great readings on my Garmin Edge. Have recommended it to all my friends and would buy again.

    • Power Meter City

      Power Meter City

      Hi Hans. Thanks for the note on your 4iiii. We’re glad you like it!

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