Abstract: A bicycle bag having a coupling device arranged on a rear wall thereof for detachable coupling with a coupling section arranged on a bicycle. The elements of the coupling device are neither unsightly nor difficult to manipulate since the coupling device is designed with at least one window in a flat reinforcement plate which is built into the rear wall of the bicycle, is fitted on the outside with an external covering, and includes a cutout above the window, which can be closed by a cover and/or is fitted with an inner covering on the inner side of the reinforcement plate. Suspension elements are also included in the window to receive the coupling section.