Chain drive comprising: a) a driving sprocket, b) at least one driven sprocket and c) an endless chain wound around said driving and driven sprockets and comprising a plurality of links; each of said links comprising: - two pivot pins parallel and transversely spaced apart from each other, and - strips extending between said two pivot pins and having opposite end portions through which said pivot pins pass; d) means for controlling wear of said chain; said means for controlling wear comprising detector means; when one of the strips breaks into two pieces during use, the two pieces tend to turn about the respective pivot pins with respect to the strips that are still intact during the movement of the chain; characterized in that: each of said links comprises at least three strips; said means for controlling wear further comprise emitter means adapted to emit an acoustic or visual warning signal; and said detector means are able to detect the breakage of said one of the strips and comprise: - at least one portion made of electrically insulating material; - one detecting metal portion, which is at least partly housed in said portion of electrically insulating material and has a side surface facing towards said chain; said side surface being spaced apart from said links when said strips are intact; said side surface being adapted to cooperate in sliding manner with the turned pieces of the broken strip; - an electric wiring connecting said detecting metal portion to said emitter means, so that said emitter means emit said acoustic or visual warning signal for replacement of said endless chain in response to a breakage signal received from said detector means. a) a driving sprocket, b) at least one driven sprocket and c) an endless chain wound around said driving and driven sprockets and comprising a plurality of links; each of said links comprising: - two pivot pins parallel and transversely spaced apart from each other, and - strips extending between said two pivot pins and having opposite end portions through which said pivot pins pass; - two pivot pins parallel and transversely spaced apart from each other, and - strips extending between said two pivot pins and having opposite end portions through which said pivot pins pass; d) means for controlling wear of said chain; said means for controlling wear comprising detector means; each of said links comprises at least three strips; said means for controlling wear further comprise emitter means adapted to emit an acoustic or visual warning signal; and said detector means are able to detect the breakage of said one of the strips and comprise: - at least one portion made of electrically insulating material; - one detecting metal portion, which is at least partly housed in said portion of electrically insulating material and has a side surface facing towards said chain; said side surface being spaced apart from said links when said strips are intact; said side surface being adapted to cooperate in sliding manner with the turned pieces of the broken strip; - an electric wiring connecting said detecting metal portion to said emitter means, so that said emitter means emit said acoustic or visual warning signal for replacement of said endless chain in response to a breakage signal received from said detector means. - at least one portion made of electrically insulating material; - one detecting metal portion, which is at least partly housed in said portion of electrically insulating material and has a side surface facing towards said chain; said side surface being spaced apart from said links when said strips are intact; said side surface being adapted to cooperate in sliding manner with the turned pieces of the broken strip; - an electric wiring connecting said detecting metal portion to said emitter means, so that said emitter means emit said acoustic or visual warning signal for replacement of said endless chain in response to a breakage signal received from said detector means.