The disengageable pulley device includes a pulley mounted on an internal transmission element, and a free wheel provided with a plurality of wedges and with a cage for the wedges, said free wheel being designed to provide one-way engagement between the pulley and the internal transmission element. The device includes an elastic connecting member provided with a first fixing part for fixing it to the internal transmission element, with a second fixing part for fixing it to the cage, and with a working part between said fixing parts, said working part being radially moveable relative to the internal transmission element and being adapted to exert a circumferential return force on the cage.