2(1)The annual rate of vehicle excise duty applicable to a motorcycle which does not exceed 450 kilograms in weight unladen is—
(a)£15 if the cylinder capacity of the engine does not exceed 150 cubic centimetres,
(b)£35 if the vehicle is a motorbicycle and the cylinder capacity of the engine exceeds 150 cubic centimetres but does not exceed 250 cubic centimetres, and
(c)£55 otherwise.
(2)Where a motorbicycle which was constructed before 1933 has an engine the cylinder capacity of which exceeds 150 cubic centimetres, it is to be treated for the purposes of sub-paragraph (1) as having an engine the cylinder capacity of which does not exceed 150 cubic centimetres.
(3)In this paragraph—
“motorcycle” means a motorbicycle or a motortricycle,
“motorbicycle” includes a two-wheeled motor scooter, a bicycle with an attachment for propelling it by mechanical power and a motorbicycle to which a side-car is attached, and
“motortricycle” includes a three-wheeled motor scooter and a tricycle with an attachment for propelling it by mechanical power.
(4)For the purposes of this paragraph the cylinder capacity of an engine shall be calculated in accordance with regulations made by the Secretary of State.