Authorized dealer

4iiiiPower meters

PRECISION 3+ crank power meters from Alberta, Canada, pre-installed by 4iiii on new Shimano cranks. Left-side or dual-sided, shipped to the continental US or picked up free in Chicago.

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Road rider climbing on a bike with a 4iiii power meter

The range

4iiii
4iiii PRECISION 3+ PRO on a Shimano Dura-Ace crankset
Road · Dual-sided

PRECISION 3+ PRO

A new Shimano Dura-Ace R9200 or Ultegra R8100 crankset with a meter on each arm, for true left/right balance.

Rider on a road bike through autumn woods
Road · Left side

PRECISION 3+ road

A new Shimano 105, Ultegra or Dura-Ace left arm with the meter on it. Swap your left arm and ride with power.

Gravel rider on a mountain road below snow-capped peaks
Gravel and MTB · Left side

PRECISION 3+ gravel and MTB

The same meter on Shimano GRX, XT and XTR left arms, sealed to IPX7 for mud, rain and the hose.

Rider in a 4iiii jersey on an open road
Heart rate

Viiiiva

4iiii's chest-strap heart rate monitor, 540+ hours on a battery. Watts and heart rate side by side.

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28 products
See all 28 4iiii products

About 4iiii

4iiii is a power meter maker from Cochrane, Alberta. Its PRECISION 3+ meter is a slim pod on the crank arm, clear of the pedals and the frame, and every one here comes Ride Ready: installed by 4iiii at the factory on a brand-new Shimano crank.

The left-side PRECISION 3+ reads the left leg and doubles it for total power. The PRECISION 3+ PRO puts a meter on both arms of a complete Dura-Ace or Ultegra crankset, which adds true left/right balance, pedal smoothness and torque effectiveness. Both read within ±1%, pick their terrain mode on their own, talk ANT+ and Bluetooth, are sealed to IPX7 and carry Apple Find My.

Dragonspine Cycling is an authorized 4iiii dealer in Chicago. Items that are not on the shelf ship to the continental US once they arrive, so allow extra time for processing and delivery. Pickup at 4357 N Milwaukee Ave is free. Call +1 (872) 946-7006 or email support@dragonspinecycling.com to confirm the right crank length and chainrings.

FAQ

Left-side or dual-sided?
The PRECISION 3+ left-side meter reads the left leg and doubles it for total power. It comes on a new Shimano left crank arm that replaces yours. The PRECISION 3+ PRO is a complete Shimano Dura-Ace R9200 or Ultegra R8100 crankset with a meter on each arm, which adds true left/right balance, pedal smoothness and torque effectiveness.
What does Ride Ready mean?
4iiii installs the meter at the factory on a brand-new Shimano crank arm or crankset. You swap it for your current left arm, or install the crankset the standard Shimano way, pair it and ride. Nothing has to be sent away.
Which cranks, lengths and chainrings are there?
Left-side meters come on Shimano 105, Ultegra, Dura-Ace, GRX, XT and XTR left arms, and each listing shows its crank lengths. The PRO comes as Dura-Ace R9200 in 165 to 175mm with 50/34, 52/36 or 54/40 rings, and as Ultegra R8100 in 165 to 175mm with 50/34 or 52/36 rings. Options vary by length, so the listing shows what can be ordered.
Which bike computers and apps does it work with?
PRECISION 3+ sends power and cadence over ANT+ and Bluetooth, so it pairs with bike computers, sports watches and indoor training apps.
How long does the battery last?
4iiii rates the left-side PRECISION 3+ at up to 800 hours and the PRO at up to 550 hours. Both are sealed to IPX7, and Apple Find My lets an iPhone show where the bike is.
What is the warranty?
4iiii covers its power meters for 3 years and its other products for 1 year. For a claim, call or email us with your order number.
How long does delivery take?
Items that are not on the shelf in Chicago are ordered for you, so allow extra time for processing and delivery. Economy shipping is free on orders of $75 or more within the continental US, and pickup at Dragonspine Cycling, Chicago is free.

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