Train and race with accurate, dual-sided power straight from your cranks. The Shimano Ultegra FC-R8100-P builds true left-and-right power measurement into a lightweight Hollowtech II road crankset, so you can pace efforts, balance your pedal stroke and review every ride without bolting on a third-party sensor. This version is supplied as crank arms only (without chainrings), making it a clean upgrade if you already have your preferred Ultegra-compatible rings.

Highlights

  • True dual-sided power, measuring left and right legs independently for accurate left/right balance
  • Optimised measurement accuracy of plus or minus 1.5 per cent
  • Integrated, rechargeable Li-ion battery with up to 300+ hours of ride time
  • Wireless ANT+ and Bluetooth LE for head units, trainers and apps
  • Lightweight Hollowtech II aluminium crank arms for efficient power transfer and crisp shifting
  • 170.0 mm crank length; supplied without chainrings

Accurate, dual-sided power

Strain sensors on both crank arms measure each leg separately rather than estimating from one side, giving you a genuine left/right balance figure and a measurement accuracy of plus or minus 1.5 per cent. The result is dependable data you can trust for pacing intervals, FTP testing and long-term training analysis.

Ride longer between charges

The waterproof, rechargeable lithium-ion battery is built into the crank and delivers up to 300+ hours of ride time, so charging is occasional rather than a pre-ride chore. It pairs over both ANT+ and Bluetooth LE, connecting easily to cycling computers, smart trainers and training apps.

Hollowtech II performance

The lightweight aluminium crank arms use Shimano's Hollowtech II construction with a 24 mm spindle for high stiffness, low weight and efficient, responsive power transmission that suits Ultegra-level road riding.

Compatibility & fit

  • Designed for Shimano 2x12-speed road drivetrains (Ultegra R8100 family)
  • Hollowtech II 24 mm spindle; use with a compatible 24 mm Shimano bottom bracket (e.g. threaded SM-BBR60 or press-fit SM-BB72-41B), sold separately
  • 110 mm BCD — accepts Shimano 12-speed road chainrings (sold separately; not included with this crankset)
  • 44.5 mm chainline; 148 mm Q-factor
  • Crank arm length: 170.0 mm

If you are unsure which bottom bracket or chainrings suit your frame and drivetrain, contact Tune Cycles and we'll help you match the right parts.

Shimano warrants this Ultegra component to be free from defects in materials and workmanship for a period of two years from the date of original purchase. The warranty covers manufacturing defects and does not cover damage caused by accident, misuse, improper installation, crash damage, or normal wear and tear. Retain your proof of purchase, as it is required for any warranty claim.

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

This warranty is in addition to, and does not limit, 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 to 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 legs independently
  • Measurement accuracy of plus or minus 1.5 per cent
  • Integrated, waterproof rechargeable Li-ion battery
  • Up to 300+ hours of ride time per charge
  • Wireless ANT+ and Bluetooth LE connectivity
  • Lightweight Hollowtech II aluminium crank arms
  • 24 mm spindle for high stiffness and efficient power transfer
  • 2x12-speed Shimano road compatibility (Ultegra R8100)
  • 110 mm BCD; 44.5 mm chainline; 148 mm Q-factor
  • 170.0 mm crank length; supplied without chainrings
BrandShimano
SeriesUltegra R8100
ModelFC-R8100-P
TypeDual-sided power meter crankset (crank arms, without chainrings)
Speed2x12-speed
Crank length170.0 mm
Crank arm materialAluminium
Spindle / interfaceHollowtech II, 24 mm
BCD110 mm
Chainline44.5 mm
Q-factor148 mm
Power measurementDual-sided (left and right independent)
AccuracyPlus or minus 1.5 per cent
BatteryIntegrated, waterproof rechargeable Li-ion
Ride timeUp to 300+ hours (depending on settings)
ConnectivityANT+ and Bluetooth LE
ChainringsNot included (sold separately)
SKU SHM-IFCR8100PCXXD
Barcode # 4550170172848
Brand Shimano

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