Most of us take it for granted that we can modify our bikes. As long as the VIN number is correct and the modifications are not visibly unsafe, there’s rarely a problem.
But in some countries, the regulations are real tough. Several territories in Southeast Asia make it virtually impossible to register a custom bike. And in Germany, Switzerland and Austria, there’s the notorious TÜV system.
TÜV requires official approval for almost every modified part fitted to a bike. The frame cannot be welded or drilled or deformed in any way. Even a new muffler must have an approval sticker—and be designed for the model of bike you’re riding.
This makes life extremely difficult for custom builders in the Germanic countries.…