The drive-side half of a dual-sided system: a new Shimano Ultegra FC-R8100 drive-side crank with chainrings, with 4iiii's Precision 3+ PRO drive-side pod already fitted. Pair it with a Precision 3+ left-side meter and you move from single-sided power to full left/right data.

Highlights

• Turns a Precision 3+ left-side meter into a dual-sided Precision 3+ PRO system
• Adds left/right balance, pedal smoothness and torque effectiveness
• Ride Ready: the pod is fitted to a new FC-R8100 drive-side crank with chainrings
• ±1% accuracy; data reaches your head unit over ANT+ or Bluetooth
• 20 g pod, CR2032 coin cell, up to 550 hours
• IPX7 water resistance and a 3-year 4iiii warranty

How the upgrade works

This listing is the drive side only. It pairs with a 4iiii Precision 3+ left-side meter, which is where the Apple Find My feature lives. 4iiii notes that an older Precision 3 left pod (without Find My) must be upgraded to 3+ before it will work with a drive-side meter. For a matched set, use a Precision 3+ Ultegra R8100 left crank in the same length.

Set-up and calibration

Wake both pods by turning the crank three or four times, then select both in the 4iiii app and pair them together so they link as a dual. On your head unit, connect only the left pod (identified by its ANT+ ID) as the power sensor. Zero offset with the bike upright and still and the cranks at 12 and 6 o'clock, left arm down. Apple Find My lives in the left pod and is set up from the Find My app on an Apple device.

Fitting at Tune

Fitting, pairing and calibration are separate workshop services and aren't included in the price. The Tune workshop can check your bottom bracket, fit the crankset with the correct Hollowtech II tools and torque, check clearance on both sides, and pair and zero the meter. If your frame needs a new bottom bracket, the right BB tool or press for your shell matters, and we'll quote it separately.

Options

Compatibility & fit

Shimano Ultegra FC-R8100 drive side: 12-speed, Hollowtech II, 110mm BCD four-arm spider, 44.5mm chainline, for an HG 12-speed chain. It runs in a Hollowtech II bottom bracket (not included; Shimano recommends SM-BBR60 threaded or SM-BB72-41B press-fit). 4iiii notes that some frames with wide or flared bottom bracket shells may not clear the drive-side pod, so talk to us before ordering if your frame has one.

Warning: This product contains a button/coin battery. Keep new and used batteries out of reach of children. Swallowing can cause serious injury or death within hours. Seek medical attention immediately if a battery may have been swallowed or placed inside any part of the body.