2011 ORS § 801.345¹
Moped means a vehicle, including any bicycle equipped with a power source, other than an electric assisted bicycle as defined in ORS 801.258 (Electric assisted bicycle) or a motor assisted scooter as defined in ORS 801.348 (Motor assisted scooter), that complies with all of the following:
(1) It is designed to be operated on the ground upon wheels.
(2) It has a seat or saddle for use of the rider.
(3) It is designed to travel with not more than three wheels in contact with the ground.
(4) It is equipped with an independent power source that:
(a) Is capable of propelling the vehicle, unassisted, at a speed of not more than 30 miles per hour on a level road surface; and
(b) If the power source is a combustion engine, has a piston or rotor displacement of 35.01 [bad link] to 50 cubic centimeters regardless of the number of chambers in the power source.
(5) It is equipped with a power drive system that functions directly or automatically only and does not require clutching or shifting by the operator after the system is engaged. [1983 c.338 §59; 1985 c.16 §19; 1997 c.400 §5; 2001 c.749 §25]