A vehicle stabilising means comprises a cradle (23) supported from a mounting (17) to lie to one side of the mounting, a rotor (19) supported from the cradle between a pair of spaced supports (25) to be rotatably supported by the supports, a drive coupled to the rotor enabling the rotor to rotate at a substantially constant angular velocity, the rotor being rotatable about a first axis, the supports located to the side of the cradle remote from the mounting, the cradle further comprising a base (31) which is rotatably supported from the mounting to be rotatable around a second axis which is perpendicular to the first axis of rotation of the rotor and which intersects the first axis of the rotor, the mounting intended in use to be fixed to the vehicle such that in operation the mean orientation of the first and second axes are substantially perpendicular to the direction of the axis of stabilisation.