When must motorcycles be submitted for official inspection (Hauptuntersuchung)?

Motorcycles in Germany must undergo an official inspection, known as Hauptuntersuchung, every two years. This rule helps ensure that vehicles meet safety and emission standards. However, it's also important to note that if a motorcycle is re-registered (for example, if there is a change in ownership or if it is brought back after being out of service), it must pass an inspection before it can be officially registered again. Therefore, the complete answer consists of both the regular two-year inspections and the requirement for inspection during re-registration. Understanding both aspects is crucial for compliance with German traffic regulations and ensuring vehicle safety on the road.