The Reich goverment introduced a tax regulation in 1922 which made small capacity motorcycles tax-free and, after 1923, required no riders's license. These were designated as having less than three "tax horsepower", with a distinction being made between two- and four-stroke engines.

This applied to four-strokes up to an engine capacity of 210cc and two-strokes of 150cc. In 1928 the regulations were simplified, with all engines up to 200cc being tax-free.

More information: Tax & Licencing, Germany 1920s