The Tradesman Spare Wheel Carrier is a simple but effective way of securing a wheel (or wheels) to your roof rack. The spare wheel carrier will work for wheels of any size. The carrier can also be fitted to a rack with a mesh floor, the carrier fits to the cross bars but the wheel sits on the mesh floor when secured.
The carrier can be partially disassembled when it is not being used so that access to underground car parks etc. is not hindered.