Abstract: A 3-wheeled velociman having individual power transmission units 40 to each of the co-axial rear wheels 11, 12. Power to the units is supplied by a pair of hand activated levers 50, 51 each of which connects with an input shaft 41 to the respective unit via a ratchet mechanism 55 and transmits the power to the input shaft 41 in the desired forward or reverse rotational direction depending on the position of a pawl engagable with the ratchet.A gear change switch 60 controls the forward, reverse or neutral position of the pawl and consequently the rotational direction of the input shaft. The switch 60 is adjacent the hand grip of each lever 50, 51, and so is easily operated by the user. The input shaft drives an output shaft 42 on which the corresponding rear wheel is mounted.The hand levers are fulcrummed to the input shaft below and to the rear of the seat 18 and lie at an acute angle to the horizontal making operation of the levers by the user less tiring on the user's arms than on upright levers.