The present invention provides a thread-based adjustment of the position of a wheel with respect to the frame of a wheelchair on a longitudinal, horizontal and also on the vertical axis. More particularly, a wheelchair is disclosed comprising a thread-based adjustment assembly, which is used to connect a wheel axle bearing structure to the frame of the wheelchair. The adjustment assembly does not add substantial weight to the wheelchair and gives a light appearance. Furthermore, no screws and nuts for attaching the assembly to the frame are necessary. Adjustment of the position of the wheel can be achieved on a millimetre scale.
