Abstract: Motorcycles having front and rear swing arm assemblies as the suspension members therefor are employed with lower frame structures incorporating the power unit as a structural element thereof. The lower frame structures are shown to include brackets mounted to the power unit itself, separate loop frame members and an under channel member. Upper frames are shown to be associated with the lower frames. The upper frames do not support the suspension systems but do support motorcycle equipment such a fuel tanks, air cleaners and the like.

Abstract: A motorcycle structure including a power unit having a transversely mounted engine with side covers of the crankcase extending forwardly of the power unit to provide mounting points for a swing arm front suspension assembly. Pivot shafts extend between the mounting points on the side covers to receive a first end of the front swing arms. Also a cushion member extends from one of the pivot shafts to a progressive linkage on the front swing arm suspension. A rear swing arm is similarly mounted between transmission side cover plates. The front cushion member is displaced laterally from the centerline of the vehicle while exhaust pipes are displaced laterally in the opposite direction to define a compact design.