A motorcycle that does not have a side-car and that:

• is designed to move on 3 wheels in contact with the ground
• is designed so that its wheels remain perpendicular to the road in curves
• is equipped with seats that the riders must straddle
• does not have a structure partially or entirely concealing the driver and passenger, except the part in front of the driver and the seat backrest

All 2-wheel motorcycles on which a conversion kit—composed of a metal structure and of a pair of auxiliary wheels aligned on the axle of the motorcycle’s back wheel—has been installed are also considered to be 3-wheel motorcycles.