A vehicle has a chassis (11) with front and rear axles (12, 13) suspended from the chassis for vertical and roll movement relative to the chassis. The axles are each mounted on the chassis via an upper pivotal mounting means in the form of an upper pair of arms (12a, 13a) which is pivoted on the chassis for vertical pivoting movement relative thereto and which carry an axle support (15, 16) on which the axle (12, 13) is free to pivot in the roll mode. A second lower pair of pivoting arms (12b, 13b) also connect each axle (12, 13) to the chassis to control fore and aft movement of the axle relative to the chassis. The line of action of the forces (F1-F4) applied to the chassis (11) by the upper arms (12a, 13a) at one end of the chassis are be substantially aligned with the line of action of the forces applied to the chassis by the lower arms (12b, 13b) at the other end of the chassis to reduce and tendency for the chassis to be twisted by these forces. A first damping means (19) acts between the chassis (11) and the upper pivotal mounting means (12a, 13a) to control vertical movement of the axle relative to the chassis, and a second damping means acts between the upper pivotal mounting means (12a, 13 a) and the axle (12,13) to provide independent control of the roll movement of the axle relative to the chassis.