A suspension unit assembly comprises a strut having a first end and a second end and a coupling disposed at the first end of the strut. The coupling has a strut part connected to the strut and a mounting part configured to tilt relative to the strut part of the coupling. A spring is disposed about the strut, one end of the spring being restrained relative to the mounting part of the coupling so that tilting movement between the strut part and the mounting part of the coupling causes the spring to deform and provide a return force that acts to return the coupling to an equilibrium position.