Specifications:
Application: Road
Series: Dura Ace R9100
Type: BSA or ITA
Shell Width: 68 mm (BSA) or 70 mm (ITA)
Axle Diameter: 24 mm (Hollowtech II)
Technical Information:
Bearings: steel
Bottom Bracket Cup Material: aluminium
Features:
- small ball bearings keep weight low
- bearing cups anodized
- recommended for Dura Ace FC-R9100, FC-R9100-P, FC-9000
Technology:
Hollowtech II
The outboard bearings offer better weight distribution and more stability that provides a more efficient power transfer. The diameter of the bearing axle (24 mm) was an important factor in development because the axle has a positive effect on stiffness, stability, weight, and rotating efficiency.