What is "twike"

The Twike (a contraction of "TWin" and "bIKE") is a human-electric hybrid vehicle (HEHV) designed to carry two passengers and cargo. Basically a velomobile with an electrical hybrid engine, it can be driven in electric-only mode or electric + pedal power mode. Pedaling warms the user, making electric heating in winter unnecessary, extends the range of the vehicle but does not substantially add to the vehicle's top speed.

Constructed of lightweight materials such as aluminium (frame) and plastic (shell), the 246 kg (542 lb) (unladen, varying with battery weight) tricycle vehicle first used NiCd batteries, later Li-Mn, LiFePO and LiIon. Typically ranges reach from 50 to over 500 km depending on battery size, type, status on one side and speed and altitude profile and load on the other. Energy is reclaimed while driving through regenerative braking, and load is removed from the electric system by use of the pedalling system which transfers its input directly to the drivetrain (i.e., both systems operate in parallel, not in series).