Abstract: A vehicle propelling assembly to propel a vehicle in a given direction comprises a pair of propelling members (19a, 19b) each having a body portion (20a, 20b) which rotates about a rotation axis extending substantially at right angles to the direction of travel of the vehicle. Body portions (20a, 20b) extend along a plane which is substantially in alignment with the rotation axis and include a curved ground or fluid engageable portion (22a, 22b). The vehicle propelling members (19a, 19b) can be mounted to ends of an axle assembly (15) which can be secured to a vehicle through a coupling assembly comprising a ball and socket assembly (25) and connecting struts (30, 31), which are pivotally connected at one end to axle assembly (15) and at the other end to a connecting member (32) which itself is pivotally mounted for movement about a vertical axis. The coupling arrangement accommodates the various forces acting on the axle assembly upon rotation of the propelling members.