A front two-wheel suspension system having a pair of left and right front wheels includes: left and right upper kingpin axles that support the left and right front wheels and are pivoted in a yaw direction by a steering shaft; left and right knuckle arms that are coupled to the left and right upper kingpin axles and pivoted in the yaw direction by the steering shaft; left and right upper arms that couple the left and right knuckle arms and left and right cushion units; and left and right first pivots that make the left and right knuckle arms and the left and right upper arms pivotable in the yaw direction. The upper kingpin axles and the first pivots are coaxial.