Abstract: A foldable bicycle (1) includes a frame (100) subdivided into two frame halves (144, 145); frame-coupling means (300) intercoupling the two frame haves (144, 145), enabling those two frame halves (144, 145) to pivot relative to each other about a substantially vertical pivotal axis (143); and frame-locking means for locking the frame-coupling means (300) in an unfolded condition of the bicycle (1). According to an important aspect of the present invention, the saddle arm (110) can pivot about a substantially horizontally directed pivotal axis (201), and a forwardly directed pivotal movement of the saddle arm (110) uncouples a locking of the frame-coupling means (300) to permit a pivotal movement of the frame-coupling means (300).