Abstract: Apparatus for mounting a sidecar to a motorcycle having a vertically disposed trapezoid-shaped frame section comprised of elongate struts interconnected at their ends defining a first vertex adjacent the motorcycle seat cushion and second and third vertices substantially below and in front of the first vertex includes three mounting bracket plates that are secured to the frame adjacent the three vertices, respectively. In one embodiment, three mounting brackets overlie two struts of the frame adjacent the vertex and are respectively clamped thereto by U-bolts. In another embodiment, a front engine mount of the motorcycle adjacent the third vertex is replaced by a mounting bracket plate which is secured to both the engine block and a frame member. Each mounting bracket plate carries the male portion of a clevispin connector for releasably attaching the sidecar to the mounting bracket plates.

Abstract: Apparatus for mounting a sidecar to a motorcycle adapted for adjustment by the motorcycle rider during transit to alter the orientation of the motorcycle relative to vertical to match the needs dictated by varying road conditions by providing pivotal connectors located along an axis substantially parallel to the direction of travel for relative pivotal motion between the sidecar and the motorcycle and by providing all other connectors spaced from said axis with means for adjusting their effective length.