The invention solves the issue of stiff mounting of a wheel to a bicycle frame. The essential feature of the invention is that in the seating nests of the axle are bulges and hollows with slanting surfaces. The outer contour of the axle's wall section, which is parallel to the wheel symmetry plane which goes through the slanting surface, has a non-circular shape, preferably the shape of a regular polygon or similar to a regular polygon or an irregular polygon or the shape of an irregular closed curve.