Abstract: The invention relates to a bicycle lock (1), comprising locking means (5,8) for locking a bicycle (10), and releasing means (6) for removing the locking. The releasing means (6) can be operated with a pass (2), which is provided with a valid operating code (3). For this purpose, the lock comprises reading means (15), preferably non-contact, by means of which the operating code (3) can be read out and compared with a code preprogrammed in the lock. In order to save energy consumption, the reading means are preferably provided with switching means, which are preferably automatically switched on when the pass is brought into a reading position. The invention further relates to a system for giving bicycles on loan, wherein each bicycle is provided with a lock according to the invention, and wherein issue and collection of the bicycles is managed with the aid of the issue and collection of passes (2).