Abstract: A motorcycle comprising a frame with a side structure supporting a liquid-cooled engine, comprising at least one engine-coolant radiator, characterized in that said engine-coolant radiator is positioned behind the steering column and extends laterally on either side of the median longitudinal vertical plane of the motorcycle, the upper edge of said radiator being positioned above a horizontal plane passing through a point located in the upper two thirds of the axis of the steering column, said frame with a side structure having a housing for receiving the upper portion of said engine-coolant radiator, the engine-coolant radiator being positioned substantially vertical, the median plane of the radiator forming an angle of ?20° to +20° relative to the vertical plane.

Abstract: A motorcycle comprising a hollow self-supporting shell integrating the steering column, means for securing the engine and means for securing the suspension system, said shell having an inner space forming a petrol tank, said shell also including the driver's seat. Said shell has hollow spaces which are closed on either side of the median longitudinal vertical plane. The driver's seat is preferably formed by an extension of the hollow spaces.