A frame unit for a two-wheeled vehicle may comprise a main frame. The main frame may be formed by a first partial shell and a second partial shell that is joined to the first partial shell. The first partial shell and the second partial shell may be produced from a material comprising steel. The main frame may further comprise an upper tube, a lower tube, a seat tube, and/or a head tube. A rear section may be joined to the main frame and may include a chain stay and/or a seat stay. Further, each of the first and second partial shells may form a lateral half of the main frame, and the first and second partial shells may have a C-shaped cross section. The frame unit avoids the disadvantages of the prior art and offers a high degree of design freedom.