W. Va. Code § 17C-1-70
For the purpose of this section, the term "electric bicycle" means a two or three wheeled vehicle with fully operable pedals and an electric motor of fewer than 750 watts. There is a "three-class system" to differentiate between the models and top-assisted speeds of electric bicycles.
"Class 1" electric bicycles have a motor that provides assistance only when the rider is pedaling, and that ceases to provide assistance when the e-bike reaches 20 mph.
"Class 2" electric bicycles have a motor that may be used exclusively to propel the bicycle, and that is not capable of providing assistance when the e-bike reaches 20 mph.
"Class 3" electric bicycles have a motor that provides assistance only when the rider is pedaling, and that ceases to provide assistance when the e-bike reaches 28 mph.
"Throttle" refers to a device that controls the flow of power to the electric motor on an electric bicycle for the purpose of propelling the electric bicycle.
W. Va. Code § 17C-1-70