The first new design after the war came out in 1921 and was obviously in keeping with the spirit of the times: The single-cylinder engine with 350 cc displacement produced 3 hp, which was transferred to the rear wheel by means of a belt – cheap and not particularly good.

Three years later, the chain drive, already common at NSU before the war, celebrated its resurrection. Now there was also a new front fork with parallelogram suspension and shock absorbers. From 1927 onwards, the engine and three-speed gearbox were combined in one block, which also contained the primary transmission, magnetic drive and oil pump.

A side-controlled touring model cylinder or a head-controlled sports model cylinder could be mounted on top of this, with the same connection dimensions. When engines up to 200 cc

became tax-free in 1928, a corresponding model (NSU 201 R) was added, and a 300 cc engine (NSU 301 T) was also added to the model range. In 1930, the first two-stroke engine with 175 cc was introduced (NSU 175 Z).

The increasing motorbike boom was due to a brand-new driveway behind the factory, which, at 1,670 m long and 5 m wide, was one of the most modern in Germany in this field. It was opened in 1929.

In 1929, a new chief designer took up his post at NSU, the Englishman Walter William Moore. He had previously worked at Norton, where he had designed the propeller shaft engine that would later become a legend. Apart from the sports models, his signature at NSU was on the OSL series with 200, 250, 350, 500 and 600 cc engines, which dominated the range until the 1930s.

In addition, Neckarsulm had been making efforts to penetrate the sector of inexpensive everyday vehicles since the end of the 1920s. This had begun with the NSU 201 R and continued in 1931 with the Motosulm. This was a motorised bicycle with a 1.2 hp two-stroke engine over the front wheel, which could reach 35 km/h after all. At the beginning of the 1930s, the so-called ZDB models followed, all of them equipped with a two-stroke engine with low production costs.

Finally, in 1936, a 100-cc motorbike with bicycle cranks in men‘s and women‘s versions was on the NSU stand at the International Automobile and Motorcycle Exhibition in Berlin. Its model name was Quick after a spontaneous suggestion by a Berlin woman. It cost 290 Reichsmarks and consumed just under two litres of fuel per 100 km. The motorbike was a smash hit: NSU built over 1/4 million of them!