A forged head pipe for a motorcycle frame is integrally formed and includes a main frame attachment portion, a pipe portion, and a lower extension extending downwardly from the pipe portion. A down frame attachment portion is provided on the lower extension, and is spaced away from the main frame attachment portion and the pipe portion. A down frame is welded to the down frame attachment portion by contacting the same without inserting the same. The down frame attachment portion is configured from a connecting portion, extending in parallel to the pipe portion, and an extension extending rearwardly from a lower end portion of the connecting portion. By eliminating an insertion socket, manufacturing cost is reduced, and welding quality is improved by spacing the down frame downwardly below the main frame attachment portion and the pipe portion, to which a high load is applied.