To reduce moment of inertia of steering by a direction changing gear box.

In a direction change gear train 23 connected to a drive shaft 21 through a joint 22, a direction change part input shaft 40 extended in an extension direction of the drive shaft 21, direction change part intermediate shaft 43 arranged in parallel in the vertical direction to this shaft 110 and a direction change part output shaft 46 placed orthogonal to this shaft 43 to extend in the car width direction one side are provided, this direction change part output shaft 46 is made adjacent to an axial line (steering axial line ST) of a head pipe 10. A direction change part drive sprocket 47 is provided in one end of the direction change part output shaft 46, a chain 24 is wound between this sprocket and a front wheel sprocket 26.