Abstract: A removable gooseneck hitch ball has a hitch ball extending over a neck and supported by a shank, possibly with the hitch ball on a pivoting head. The shank has a plurality of arc contact surfaces (such as four) collectively defining a cylinder centered on the shank's central axis. Flat contact surfaces extend parallel to the shank's central axis and inside the cylinder defined by the arc contact surfaces (such as four flat contact surfaces defining a square). The shank can be matingly received in a cylindrical socket of the towing vehicle with the arc surfaces in contact with the cylindrical socket or can be matingly received in a prism shaped (square in horizontal cross-section) socket with the flat surfaces in contact with the prism shaped socket.

Abstract: A bike rack which is mountable from a traditional hitch receiver and includes a main beam extending upwardly and rearwardly off a post. The main beam includes a lower section which is hinged to the post and holds one or more preferably two bikes each with their top tube extending horizontally and transversely under the lower section, as well as an upper section which is hinged to the lower section and holds one or more preferably two bikes each with their top tube similarly under the upper section. Each bike is placed with its top tube received in two pivotable, spaced oblong mounts. Two bikes can be mounted while the upper section is folded over, before unfolding/extending the upper section to mount the third and fourth bikes.