The present invention relates to castor wheel assemblies, in particular but not exclusively, to castor wheel assemblies of a type suitable for use with trolleys, for example supermarket trolleys or luggage trolleys. Embodiments of the invention provide a swivel castor wheel assembly configured to support an object to be moved across a surface, the assembly comprising a swivel castor wheel having an axis of wheel rotation and a steering axis and mounted on a first member, wherein the first member is configured for connection to the object in such a way that the steering axis can be moved between first and second different rake angles without substantially changing a height of the object over the surface.