A new Shimano Ultegra FC-R8100 crankset with 4iiii's dual-sided Precision 3+ PRO pods already fitted. You get separate left and right power, pedal-stroke metrics and Apple Find My tracking, for 29 g of pods.

Highlights

• Dual-sided power at ±1%, with left/right balance, pedal smoothness and torque effectiveness
• Ride Ready: the pods are fitted at the factory to a new FC-R8100 crankset
• Apple Find My in the left pod, so you can locate your bike from an iPhone, iPad or Mac
• ANT+ and Bluetooth, for head units, watches and indoor training apps
• Two CR2032 coin cells, up to 550 hours on the drive side
• IPX7 water resistance and a 3-year 4iiii warranty

The crankset

Shimano Ultegra FC-R8100 is a 12-speed Hollowtech II road crankset with a 110mm BCD four-arm spider, 44.5mm chainline and 148mm Q-factor. The arms are aluminium and the outer ring is aluminium/CFRP. Shimano quotes 700 g (50/34T), 711 g (52/36T) at 170mm, without bottom bracket and before the 29 g of pods.

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

Built for 12-speed Shimano road drivetrains with an HG 12-speed chain. It needs a Hollowtech II bottom bracket, which isn't included: Shimano recommends SM-BBR60 for threaded 68mm or 70mm shells and SM-BB72-41B for press-fit. For other shell standards, ask us which Hollowtech II bottom bracket suits your frame. 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.