A vehicle (1) comprises a frame (17); a front ground engaging sphere (2) which is rotatable about a first axis which is transverse and fixed relative to the frame (17); a rear ground engaging sphere (3) which is rotatable about a plurality of axes, and gripping portions (11) which are provided towards the front of the vehicle (1), for a rider to hold. A support member (25) is connected pivotally to a rear portion of the frame (17) and projects longitudinally of the vehicle (1) and downwardly from the point of connection to the frame (17) to a remote part of the support member (25). The rear sphere (3) is connected to the remote part of the support member (25) for rotation about a second axis which is transverse and fixed relative to the support member (25). The support member (25) is pivotal with respect to the frame (17) about a third axis which extends downwardly and longitudinally of the vehicle (1).