An electrical connector, which is detachably installed in a lower fork of a bicycle frame, the electrical connector comprising a fixed seat and an inserted seat, the fixed seat being installed in the lower fork, the fixed seat being hollow in shape, the inserted seat being inserted in the fixed seat in a way that the inserted seat is movable back and forth, the inserted seat having a first end surface, a second end surface opposite to the first end surface, and a core shaft installation hole penetrating through the first end surface and the second end surface, the first end surface of the inserted seat being provided with a set of electrically conductive structure.