US Patent 9511820 Rear end structure for a bicycle frame

A continuous, one-piece bicycle frame end includes a forward portion and a rearward portion, wherein the forward portion extends from a chain stay and a seat stay, and wherein the rearward portion extends rearward from the forward portion. The frame end defines an axle receiving opening dimensioned to receive a bicycle wheel axle therein to rotate around a rotational axis. The axle receiving opening is intersected by a horizontal axis of a Cartesian coordinate system, wherein the axle receiving opening forms the origin of the Cartesian coordinate system, and the zero axis of the Cartesian coordinate system is the portion of the horizontal axis forward of the origin. A derailleur-attachment structure is located from approximately 180° to approximately 240° in the Cartesian coordinate system.