A wheel-fitment assembly enabling a physical mock-up of an optimal wheel geometry for a hub. The wheel-fitment assembly integrates into a unitary apparatus an offset measuring device, a diameter measuring device, and a width measuring device to simultaneously delineate and represent the optimal wheel's offset distance, diameter, and width. The width measuring device has two bidirectional sliding scales to simultaneously define an outer edge and inner edge of the wheel width wherein the two sliding scales are mechanically communicated by an adjustment link so that movement of one sliding scale directly affects or moves the position of the other sliding scale absent a user manually resisting such movement. The adjustment link may be an elongated rod with guide tracks, wherein each sliding scale may have guide fingers that ride along opposing ends of the same guide tracks, thereby enabling the simultaneous movement of the unrestricted two bidirectional sliding scales.