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 produce a crank that minimises the effort required for the drive and enables more efficient power transmission.
An exclusive forging process allows the production of extremely light crank arms that nevertheless guarantee maximum stiffness. The fixed connection of the right arm to the axle of the bottom bracket and its external bearing also serve an optimum relationship between stiffness and low weight.
|Material||Crank arms, inner chainring: Aluminium (anodised)|
Outer chainring: Aluminium (anodized), carbon fiber reinforced polymer (CFRP)
Axle: Steel (plated)
|Crank Arm Length||160, 165, 167,5, 170, 172,5, 175, 177,5|
|Bottom Bracket Axle Profile||24mm Hollow Shaft|
|Bottom Bracket Case Width||68mm, 70mm|
|Road - bolt circle diameter||110mm|
|Compatibility||Front derailleur: FD-R9250, FD-R8150|
Bottom bracket: BB-R9100 (thread type), SM-BB92-41B (Press Fit)
Chain: CN-M9100, CN-M8100, CN-M7100, CN-M6100
|Weight||approx. 685 grams (50-34 teeth)|
approx. 692 grams (52-36 teeth)
approx. 714 grams (54-40 teeth)