Sorry, this product is no longer available!
4iiii Precision Ultegra 6800 Powermeter is no longer available at Merlin Cycles. However you may find an alternative or updated product below.

This item was discontinued 24th June 2019.

If you require help finding an alternative to this product please contact customer services.

Code: FC-6800-PML100
4iiii Precision Ultegra 6800 Left Arm Powermeter
Accurate measurement of cycling effort is vital for anyone who takes cycling seriously. PRECISION powermeters provide industry leading accuracy, together with reliable cadence data. PRECISION 3D technology is capable of measuring tri-axial strain on the crank arm, ensuring the accuracy of the measurement. Designed to work flawlessly with Bluetooth and Ant+ head units, PRECISION powermeters offer an accurate, lightweight, durable and affordable method of measuring rider power.    
PRECISION power meters are installed on a new Shimano left crank arm (105, Ultegra, or Dura-Ace). These crank arms will fit bottom brackets using the Hollowtech ii format.
  • 3D powermeter technology (patent pending) measures tri-axial strain on your crank arm
  • Accurate, consistent data
  • Lightweight, compact design
  • Battery status indicator via 4iiii app
  • Compatible with ANT+, Bluetooth Smart head units, smartphones, and other 4iiii products
  • User-friendly app and configurable rider compensation scale factor
  • Easy setup and maintenance
  • Weight: 9 grams
  • Data accuracy: +/- 1% error margin
  • Battery life: 100+ riding hours on 2032 coin cell battery


Note: Check your frame clearance before you order by downloading and printing the compatibility guide Click Here
Great price on this 4iiii power meter, and so simple to set up and use. Arrived in about 10 days from the UK to the west coast of the USA. Excited to train with power info now!
Bought this after endless problems with a stages PM. Works perfectly, even cycling in torrential rain. No need to spend more unless you're a pro.
Have used the 4iiii for 5 or so rides now in a variety of temperatures but so far all dry. Super easy to install, took only 10mins. Paired with my wahoo ELEMNT bolt and iPad (for zwift) straight away. Calibration is very easy. So far has worked flawlessly and produces power data in line with a stages power meter which I have used before. I weighed it before installation, the new crank including the power meter weighed only 7g more than the existing identical crank, battery included. Arrived on time and exactly as described. So far super happy.
Merlin is my go to bike shop store. This power meter exceeds my expectations and is comparable to my Stages. Easy installation and accurate readings and even better than Stages Gen 2 because no dropout issues. At least with my bikes in the US. Highly recommend both Merlin and this power meter.
Excellent product and so easy to install and setup. Literally took 5mins from taking the old crank arm off to downloading the app and configuring the sensor.
The item I bought arrived in about a week. I mounted on my bike immediately and ran about 200 km. It worked without problem. I am satisfied with high performance.
Very easy to pair up and calibrate. Durability still to be tested
Receiver powermeter within 2 days. Installation succeeded within 10 minutes. Pairing with Garmin Edge 810 and Fenix 5 also went smoothly and without any problem. I have done 5 rides with the 4iiii now and it is a great help for training and feedback purposes. A complete new world has opened. I use the program "golden cheetah" to analyse the TCX data from my Garmins. I can greatly recommend the 4iii product and services of Merlincycles. (Especially at this great price)
Easy to install and set up.