The use of rented bicycles as an alternative means of transport has increased relatively in the last years. This increase sets a challenge to the management of shared bicycle fleets that can now be found in the majority of European cities. The main objective of this work is to design a comprehensive system which will monitor bicycle fleets using low-cost sensors. The system allows for the detection of anomalous situations, detecting possible robberies, vehicle abandonment and use of bicycles in prohibited areas. To this end, the use a multi-agent architecture is proposed for the management of the different hardware devices, for tracking, messaging and alerts that are produced by the system.