At least one slide block is installed on the saddle pole for optimal guiding, as far as possible free of play, of a saddle pole in a cladding tube, at the lower end of the saddle pole. The slide block(s) engage in a groove-shaped recess in the cladding tube, said groove-shaped recess of the cladding tube having at least one length, which corresponds to the requested adjustment stroke of the saddle pole. At least one contact surface of the saddle pole, on which a planar slide block is installed, is planar and the side of the planar slide block, which is installed on the saddle pole with the planar contact surface, also has a planar surface.