The bottom bracket bearings for use with the HollowTech II R9100 chainset which is the ultimate chainset for stiffness whilst keeping weight low for performance riding and racing.
- Bottom bracket with small ball bearings for lightweight
- Advanced seal construction for smoother rotation
Minimal bearing interface gives superbly smooth rotation. Distinctive style that exudes quality and perfection. Required for installation of R9100 chainset with a choice of English or Italian thread BB cups
Bicycle bottom brackets connect the cranks to the bike and allow the crank arms to rotate. There are various sizes of bottom bracket shell on the market so compatibility needs to be checked. The three most common frame bottom bracket shell widths are 68mm (English threaded road and mtb) 70mm (Italian threaded road) and 73mm (British threaded mtb). There are also many axle shapes and styles from JIS or ISO square tapers through to the round splined axles such as ISIS or Octalink and then there is the new external cup systems which have the axle built into the crank arms. Some frames are now using the new BB30 system which uses bearings pushed directly into the frame and removes the needs for cups to be threaded into the frame.