4iiii XT 8100 Precision 3 Left Power Meter

The 4iiii XT M8100 Precision 3 is lightweight, reliable, accurate and easy to use. Due to the super lightweight design, the sensor only adds 9 grams to a standard crank. This makes this 4iiii power meter the lightest one on the market! Also, the sensor in the Precision 3 is smaller than before, so that the power meter now fits even more frames!

Accuracy
The Precision 3 power meter is highly accurate with a deviation of only 1%. The power is measured in the left crank arm and doubled to measure the total power delivered. As for most riders, the difference between the left and right leg is very small, this power meter is an excellent choice for your bike. When you exert power through your pedals or crank, it doesn't just bend the crank, it turns and twists in all 3 dimensions. 4iiii's 3D Strain Gauge system measures this multidimensional load so that you can be confident that your unique pedal stroke is accurately measured regardless of your riding conditions.

Connectivity
The 4iiii Precision 3 power meter transmits a Bluetooth and ANT+ signal so that it can be connected to virtually all modern cycle computers of brands such as Garmin, Wahoo, Polar, Mio, Lezyne and Bryton. The calibration goes via 4iiii Device Configuration, an app for Android and IOS. Through this app you can also see the status of the CR2032 coin cell battery.

Battery life
The 4iiii has no internal battery but runs on coin cell batteries. While this means that you have to replace them every now and then, you'll be happy to know that the battery (CR 2032 button cell) lasts up to 800 hours, which is a lot longer than most internal batteries in power meters. If the battery gets below 15%, you get a message in the 4iiii Device Configuration so you can replace it in time.

• Weight: 9 grams
• Connectivity: ANT+, Bluetooth
• Accuracy: +/-1%
• Battery: CR2032 (battery life up to 800 hours)
• 3 Year warranty
• Waterproof rating: IPX7
• Active temperature compensation
• Power range: 0 - 4000W
• Cadence range: 30 - 150RPM

• Of course this crank arm fits Shimano XT M8100.

Let op: The 4iiii Precision powermeter is slightly wider than a Shimano left crank arm due to the powermeter unit. This can cause problems with some bicycle frames. To determine whether your frame is compatible, you can perform a test. To do this, you need to be able to move an 8 mm Allen key vertically between your crank arm and the chainstay. For clarification view the last product photo on this page . The 4iiii website features a nifty little document that you can print out and stick onto your crank. This way, you will know exactly between which points the 8 mm Allen key should be able to move. If there is enough room for the 8 mm key, you can assume that the 4iiii powermeter is compatible with your frame.

To mount this 4iiii powermeter you must first remove your current left crank arm. Mounting the 4iiii powermeter is exactly the same process as mounting a Shimano left crank arm.

1. Remove the left side pedal.
2. Unscrew the crank bolts on the top of the crank arm, and take out the locking pin from the slot.
3. Next, remove the crank nut with a Shimano crank extractor.
4. Now the crank arm should be loose and you can take it off the crankshaft.
5. Then install the powermeter crank arm by following the above steps in reversed order.
6. Don't forget to install your pedal on your new crankarm, and you're ready for a ride.

How can I determine which crank length I need?
Crank length refers to the length of the crank arm and is measured from the centre of the bottom bracket to the centre of the pedal axle. Bicycles usually come with with the correct crank arm length for the corresponding body size. In most cases, the length is indicated on the inside of the crank arm. If not, you can measure it yourself. It is important that the crank arm powermeter you purchase has the same length as your current crank arms.

With what software and/or hardware is this power meter compatible?
This power meter sends both ANT+ and Bluetooth signals.
Therefore this power meter is compatible with most current bike computers. However, not all computers are compatible with a power meter. To find out if your powermeter is compatible, consult its specifications. Typically, you will find that the most common Garmin and Wahoo models can be paired. The Garmin Edge Explore cannot be linked to a power meter.

The most common models are: Garmin Edge 130, 520, 530, 820, 830, 1020 &1030; Wahoo ELEMNT en ELEMNT ROAM

If you don't have a bike computer, you can also use the 4iiii app to keep track of your workout power data.

How to calibrate this power meter.
Calibrating your power meter is very important for an accurate power measurement. Make sure there is no weight on the pedals and that your right crank is up and your left crank is down (positioned vertically). Rotate the powermeter a few times so that it switches on. Then you can easily calibrate your powermeter via the 4iiii app. Another possibility is to calibrate your powermeter using your cycling computer. Most bike computers have this option, check the user manual of your bike computer to find out how to do this.