A shoe system is provided that comprises a removable upper unit and a sole unit that can be interconnected utilizing respective upper and lower connecting means. Size and form of the cross-section of the blank are selected in a manner that the contour of the finished gear rack in the toothed area does not project beyond the envelope given by the dimensions of neighboring parts of the rack-and-pinion steering gear. The system includes an infinitely variable transmission having a transmission ratio that is adjustable.