Shimano Ultegra 12v 36-52T 170mm Crank

Shimano Ultegra FC-R8100 Crankset - 2x12-speed
Ultegra R8100 – Leave Time Behind

When developing the Ultegra R8100 series, Shimano took a holistic and 100% performance-oriented approach, because with great speed comes great responsibility. Faster than ever, the 12-speed groupset for road bikes offers unmatched control and comfort anytime, anywhere, whether you're in a race for all audiences, in pursuit of a personal best time or in a walk in company

As with the Dura Ace R9200, Hyperglide+ is not only incorporated into the Ultegra's components, but its Di2 parts are also based on wireless technology to further simplify operation and ensure smooth shifting.
Shimano Ultegra FC-R8100 Crankset

As the heart of the Ultegra R8100 series 12-speed drivetrain, the FC-R8100 crank is characterized by typical Shimano shift quality and drivetrain efficiency. Not only the hollow Hollowglide chainrings, but also the lightweight Hollowtech II crank arms help optimize power transmission as well as quicker and more precise shifting operations.

Together, this results in a perfect balance between stiffness, stability, low weight and rotational efficiency. Numerous crank lengths and 50-34 or 52-36 chainrings also offer variability and optimum gear ratio for almost all riding situations.
Hollowtech II

The guiding principle of Shimano's Hollowtech II technology is the perfect balance between stiffness, stability, weight and rotational efficiency. The goal was to make a connecting rod that would minimize the effort required for actuation and allow for more efficient power transmission.

An exclusive forging process allows the production of extremely light connecting rods that, however, guarantee maximum rigidity. The fixed connection of the right arm to the bottom bracket axis and its external bearing also serve for an optimal relationship between stiffness and low weight.

Material:
arms, inner chainring: aluminum (anodized)
outer chainring: aluminum (anodized), carbon fiber reinforced plastic (CFRP)
shaft: steel (plated)

Compatibility:
front derailleur: FD-R9250, FD-R8150
Bottom Bracket: SM-BBR60 (Thread Type), SM-BB72-41B (Press Fit)
chain: CN-M9100, CN-M8100, CN-M7100, CN-M6100

Weight (170 mm, manufacturer data):
approx. 700 grams (50-34 teeth)

approx. 711 grams (52-36 teeth)