The ornamental design for a bicycle hub flange protector, as shown and described.
FIG. 1 is a front perspective view of the bicycle hub flange protector of the present invention showing my new design with the phantom lines depicting solely environmental structure and forming no part of the claim design;
FIG. 2 is an enlarged front elevational view thereof;
FIG. 3 is an enlarged side elevational view thereof; and,
FIG. 4 is an enlarged rear elevational view thereof.