The bicycle is one of the most popular means of transport for short and medium distances and has become popular with commuters, especially in urban areas. However, it seems all the more complicated to ensure the environmentally friendly replacement of cars. Once left unobserved for a moment, the bicycle thief disappears into the next side street. In 2018, 353,000 bicycle thefts were reported in Germany, 160,000 of which were insured bikes. The number of unreported cases is considerably higher. The high number of thefts and the professionalised approach show that it is not only occasional thieves who can be spoken of. Therefore, there are a few tips that should be followed when securing bicycles.