Abstract: An integral frame structure for vehicles that includes a telescopically extending tubular member with rear and front support assemblies mounted perpendicularly to the ends. Transverse cross members are perpendicularly mounted to the longitudinally extending tubular member. The tubular member has a relatively large diameter with respect to the transverse cross members that are kept in perpendicular position with respect to the tubular member defining a plane below the longitudinal upper portion of the tubular member. A load is supported by the front and rear support assemblies as well as the cross assemblies. The load is also supported by the upper longitudinal portion of the tubular member, specially, the portion adjacent to the rear portion. The structure is easily assembled and capable of being stored in a volumetrically efficient manner.