Historical background
The spirit of the times in the 1920s was defined by a "rush on speed." Motorization signified technological progress and modernization. However, taking weekend trips into the countryside in one's own car or motorcycle was a status symbol that, despite the increased production of affordable small cars, only a few achieved. Like the automobile, the motorcycle conveyed the widespread belief in technological progress and modernization prevalent in the Weimar Republic.
While motorcycles were still a luxury item before the First World War, sales figures rose sharply in the 1920s. Between 1921 and 1924, the number of motorcycles in Germany increased from just under 26,700 to around 98,000. By mid-1931, nearly 800,000 motorcycles were registered in the German Reich. In everyday German life, the motorcycle served as a fast, inexpensive, and reliable means of transportation. Neckarsulmer Fahrzeugwerke AG (NSU) was the first German company to use the assembly line in motorcycle production for the purpose of rationalization and standardization. The 1927 NSU 251 R was originally equipped with a 250cc engine. This was later replaced by a 200cc engine, produced from 1928 onwards: motorcycles up to this displacement did not require a driver's license.
After the Second World War, the goal was to motorize the nation again. This was achieved not only through the 250cc motorcycles, which could be driven with the old Class 4 driver's license, but also through the successful sales of two-wheelers.
To reach the broadest possible customer base, a new engine displacement class was introduced on January 1, 1953: 50cc! However, this definition was not entirely sufficient, as the legislature had a specific idea of how the 50cc motorcycles should be used. These were offered either as a bicycle with an auxiliary motor, officially called a moped from 1954 onwards (max. 30 kg weight plus 10% tolerance, minimum wheel diameter 580 mm, pedal cranks 125 mm long) or as a motorized bicycle (heavier than 33 kg, pedals, no maximum speed, driver's license class 4).
This is where Alfred Kreidler comes into play, whose two-wheelers didn't fit into this scheme. Due to their weight exceeding 33 kg, they were neither mopeds nor, with footrests and a kickstarter, motorized bicycles. With this, Kreidler created the class of light motorcycles, which was subsequently enshrined in the "Lex Kreidler" when the legislature amended the German Road Traffic Regulations (StVZO) again on August 24, 1953.
As a result, small motorcycles flooded the German market, with foreign manufacturers, some selling via mail order companies, also trying to spoil the party for the established German manufacturers, until the market for small motorcycles completely collapsed in the mid-1980s due to the newly introduced light motorcycles.