What cancels the permit for use of a motorized bicycle?

In the context of German traffic laws, the use of motorized bicycles is tightly regulated to ensure safety and compliance with standards. The actions of "clearing out" the silencer and modifying the gear ratio are both considered illegal modifications that can significantly affect the bike's performance and safety.

1. Clearing out the silencer: This practice can lead to increased noise levels and emissions, violating regulations aimed at controlling environmental impact and noise pollution. Such modifications make the bicycle non-compliant with technical safety standards.

2. Modifying the gear ratio: Changing the gear ratio can alter the speed and handling characteristics of the bicycle, which can create unsafe riding conditions. This modification can push the vehicle beyond its intended operational limits, undermining safety regulations.

Fitting a second rear-view mirror, on the other hand, is generally an enhancement for safety and is not typically a reason for cancellation of a permit. Therefore, it is essential to recognize that both the first two modifications are serious violations that can lead to the cancellation of the permit for the use of a motorized bicycle in Germany. Understanding these rules helps maintain safety on the roads and ensures compliance with local regulations.