"Motorized bicycle" or “moped” means any vehicle having either two tandem wheels or one wheel in the front and two wheels in the rear, that may be pedaled and that is equipped with a helper motor of not more than fifty cubic centimeters piston displacement which produces no more than one brake horsepower and is capable of propelling the vehicle at a speed of no greater than twenty miles per hour on a level surface. (ORC 4511.01(H))