Abstract: A bicycle lock including a drum housing having a cable reel rotatably mounted in said drum housing on a shaft extending through the housing. A torsion spring is operatively connected between the shaft and the reel and is placed in tension by the rotation of the reel in one direction upon the shaft. A two part bar clamp is secured to the outer side of the housing for clamping the housing to one of the bars of a bicycle frame. A flexible securing cable having a lock on one end has its other end portion wound around the reel, and extends through a guide ring secured to the housing in alignment with an opening in one side of the housing. A safety cable is extended from a point of securement on one side of the reel housing to a point of securement to the guide ring, with a bight portion positioned between the points of securement of the safety cable.