Bicycle has bottom bracket tube connected to top and bottom tubes of frame and fork connected to handlebar stem, supported by bearings in auxiliary element

摘要

A bottom bracket tube (7) is pivotably connected to the top and bottom tubes (11,9) of a frame (3) such that the connecting points (31,33,35,47) of the tubes are spaced from each other. A fork (17) is connected to the handlebar stem (13) and is supported by bearings in an auxiliary element (43) so as to rotate the fork.