An exemplary mounting bracket is configured for releasably securing a bicycle lock to a bicycle, and generally includes a housing, a pair of opposing arms, a pinion, a latch, and a manual actuator. The arms are movably mounted to the housing for movement between inward positions and outward positions, and each arm includes a rack gear. The pinion is engaged with each rack gear and correlates movement of the arms such that the arms move with one another between the outward positions and the inward positions. The latch has a latching position in which the latch is operable to maintain the arms in the inward position, and has an unlatching position in which the arms are free to move from the inward position to the outward position. The manual actuator is operable to move the latch between the latching position and the unlatching position.