BB – a common acronym for a Bottom Bracket.
There are so many different variations on a BB unit that it is impossible to list all of their components here. However, below are some of the more common and most basic components of a BB.
Bearings
Shown here in a bearing cage. (They can also be put straight into the bearing race loose or sealed within bearing units.)
Square Taper
Bearing Race and Cones
Cups
BB Shell
Lockring
Spindle
