Sensor system for mounting on a bicycle, having: a magnet which can be mounted on a rotatable part of the bicycle; a second magnet which can be mounted on a second rotatable part of the bicycle; a sensor which can be mounted on a non-rotatable part of the bicycle and is designed to capture information relating to an approach to the magnet during a rotational movement of the rotatable part; a second sensor which can be mounted on the non-rotatable part of the bicycle and is designed to capture information relating to an approach of the second magnet during a rotational movement of the second rotatable part, and a communication unit which can be mounted on the bicycle and is configured to process the information captured by the sensor according to a predefined profile and to transmit the processed information to a server via a mobile radio communication network, wherein the predefined profile comprises the predefined dimensions of the bicycle, in particular the wheel circumference of the bicycle, wherein the communication unit comprises the following: a sensor interface (122, 402) which is designed to transmit the information captured by the sensor and the second sensor to the communication unit in a wired or wireless manner; a microcontroller which is designed to process the information received from the sensor interface; and a mobile radio interface (134, 406) which is designed to transmit the information processed by the microcontroller via the mobile radio communication network; and wherein the sensor and the second sensor are integrated in the communication unit which can be mounted on a chain stay of a frame of the bicycle. a magnet which can be mounted on a rotatable part of the bicycle; a second magnet which can be mounted on a second rotatable part of the bicycle; a sensor which can be mounted on a non-rotatable part of the bicycle and is designed to capture information relating to an approach to the magnet during a rotational movement of the rotatable part; a second sensor which can be mounted on the non-rotatable part of the bicycle and is designed to capture information relating to an approach of the second magnet during a rotational movement of the second rotatable part, and a communication unit which can be mounted on the bicycle and is configured to process the information captured by the sensor according to a predefined profile and to transmit the processed information to a server via a mobile radio communication network, wherein the predefined profile comprises the predefined dimensions of the bicycle, in particular the wheel circumference of the bicycle, wherein the communication unit comprises the following: a sensor interface (122, 402) which is designed to transmit the information captured by the sensor and the second sensor to the communication unit in a wired or wireless manner; a microcontroller which is designed to process the information received from the sensor interface; and a mobile radio interface (134, 406) which is designed to transmit the information processed by the microcontroller via the mobile radio communication network; and wherein the sensor and the second sensor are integrated in the communication unit which can be mounted on a chain stay of a frame of the bicycle. a sensor interface (122, 402) which is designed to transmit the information captured by the sensor and the second sensor to the communication unit in a wired or wireless manner; a microcontroller which is designed to process the information received from the sensor interface; and a mobile radio interface (134, 406) which is designed to transmit the information processed by the microcontroller via the mobile radio communication network; and wherein the sensor and the second sensor are integrated in the communication unit which can be mounted on a chain stay of a frame of the bicycle.