Train and race with precise, dual-sided power data straight from your Ultegra crankset. The Shimano Ultegra FC-R8100-P measures each leg independently, so you can see true left/right balance, hold target watts on climbs and pace efforts with confidence — all from a fully integrated, weather-sealed unit that disappears into a clean Hollowtech II crank.

Highlights

  • Dual-sided power measurement accurate to within +/- 2.0%
  • Integrated, waterproof, rechargeable lithium-ion battery with 300+ hours of ride time
  • Wireless ANT+ and Bluetooth LE for head units, trainers and apps
  • 170 mm arms with a 50-34T compact chainring combination for 2x12-speed road
  • Cold-forged Hollowtech II aluminium arms for proven stiffness and durability

Power you can trust

Sensors on each crank arm read the pedalling force of both legs, so the numbers you see reflect what you are actually putting down rather than a doubled estimate from one side. With a stated accuracy of +/- 2.0% and automatic temperature compensation, the data stays consistent enough to build structured training around and to compare across rides and seasons.

Ride longer between charges

The rechargeable lithium-ion battery is built into the unit and sealed against water and weather. With 300+ hours of ride time on a charge (depending on connectivity settings), you can go weeks between top-ups, and a single cable recharges it without removing the crank.

Connects to everything you ride with

Dual ANT+ and Bluetooth LE broadcasting links the crankset to compatible cycling computers, smart trainers and training apps, and supports wireless firmware updates so the meter stays current over time.

Compatibility & fit

This crankset is built for 2x12-speed Shimano road drivetrains. It uses a 24 mm Hollowtech II spindle and is designed to run on Shimano Hollowtech II bottom brackets. Chainrings mount to a 110 mm 4-bolt asymmetric BCD, the chainline is 44.5 mm and the Q-factor is 148 mm. This variant comes with 170 mm arms and a 50-34T compact chainring combination, and is intended for use with a Shimano 12-speed road chain. Confirm your frame's bottom bracket standard and that you are running a 12-speed road drivetrain before ordering.

This Shimano Ultegra FC-R8100-P power meter crankset is covered by Shimano's manufacturer warranty against defects in materials and workmanship. The warranty does not cover normal wear (including chainring and drivetrain wear), damage from crashes, improper installation, unauthorised modification or misuse, or battery degradation over normal use.

For warranty support, return the item to Tune Cycles and we'll manage the claim for you.

This warranty is in addition to your rights under the Australian Consumer Law. Our goods come with guarantees that cannot be excluded under the Australian Consumer Law. You are entitled to a replacement or refund for a major failure and compensation for any other reasonably foreseeable loss or damage. You are also entitled to have the goods repaired or replaced if the goods fail to be of acceptable quality and the failure does not amount to a major failure.

  • Dual-sided power meter measuring left and right leg independently
  • Stated accuracy within +/- 2.0% with automatic temperature compensation
  • Integrated, waterproof, rechargeable lithium-ion battery (300+ hours of ride time)
  • Wireless ANT+ and Bluetooth LE connectivity for head units, smart trainers and apps
  • Wireless firmware updates supported
  • Cold-forged Hollowtech II aluminium crank arms
  • 170 mm crank arms with 50-34T compact chainrings
  • 24 mm Hollowtech II spindle; 110 mm 4-bolt asymmetric BCD
  • 2x12-speed Shimano road compatible
Part numberFC-R8100-P
SeriesShimano Ultegra R8100
TypeDual-sided power meter crankset
Speed2 x 12-speed (road)
Crank arm length170 mm
Chainrings50-34T (compact)
Power accuracy+/- 2.0%
ConnectivityANT+ and Bluetooth LE
BatteryIntegrated rechargeable lithium-ion, 300+ hours ride time
Crank arm materialAluminium (cold-forged, Hollowtech II)
Spindle diameter24 mm (Hollowtech II)
BCD110 mm, 4-bolt asymmetric
Chainline44.5 mm
Q-factor148 mm
WeightApprox. 758 g (50-34T)
SKU SHM-IFCR8100PCX04F
Barcode # 4550170821197
Brand Shimano

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