What is disclosed is a bicycle frame (1) comprising a seat tube (4) in which a saddle pillar (2) for a saddle is at least partially held, wherein the saddle pillar (2) or the main tube (12) thereof is adapted for translatory movement and height-adjustment relative to the bicycle frame (1). In this case, a rotation prevention device and a locking device, in particular a seat device, are fastened on the seat tube (4). Both securing devices act between the seat tube (4) and the main tube (12) in a form-fitting manner. In this case, the device for securing against rotation engages permanently in the main tube and the latching device can engage in, and can be disengaged from, the main tube.