Abstract: Drive apparatus (2) for a cycle (4), comprising an electric motor (6), a first pulley (8) driven by electric motor (6), a second pulley (10), an endless belt (12) which passes around two pulleys (8, 10) and is driven by first pulley (8), and a swinging link mounting (14). During use, endless belt (12) is in driving engagement with a tire (16) of a wheel (18). Mounting (14) enables the distance between centers of first and second pulleys (8, 10) and tire (16) to vary during use of drive apparatus (2), which enables drive apparatus (2) to exert on tire (16) a varying contact pressure which increases as transmitted torque increases. Mounting (14) comprises an attachment for attaching drive apparatus (2) to cycle (4), and a pivot (24).