After the end of the war, numerous private drivers took part in the sporting events that were now advertised again. The first post-war sporting fame for NSU, however, came in the form of automobiles. At the Avus opening race in 1921, an NSU 8/24 hp won its class. The drivers Klöble and Kist, already known from motorbike racing, also achieved the second best time of the day. While the two-seater they used was only a slightly modified production car, the NSU people brought out a heavier gun two years later.

In 1923, a 1.3-litre car (1,230 cc, 50 hp) derived from the standard 5/15 hp was entered on the same circuit, given additional life by a supercharger. Three such cars took 1st to 3rd place in the small car category! The car could be purchased by anyone as a compressorless sports two-seater with 30 hp, and the demand was astonishingly high. Incidentally, the Neckarsulm team managed to repeat this success the following year. In the meantime, the people between the Neckar and Sulm

rivers were again working on an innovation at the drawing board. A six-cylinder that was to be fitted with a supercharger for track racing and thus produced 60 hp.

A sportsman who later became very famous on Wanderer and Auto Union sports cars entered the first ever „German Grand Prix for Sports Cars“ in 1925 with the prototype: August Momberger.

He was a trainee at NSU at the time and won the race. The sensation was perfect. NSU had relegated the entire elite with illustrious names such as Mercedes and Bugatti to their places. The following year, another quadruple victory was due in the 1.5-litre class. The drivers were Georg Klöble, Josef Müller, Ernst Islinger and Jakob Scholl. They reached top speeds of over 175 km/h. After this car became a production car years later, it also caused a stir with its remarkable endurance performance. At the end of 1928, it covered 20,000 km without a breakdown during 18 days of uninterrupted day and night driving on the

Nürburgring. At the ADAC endurance race in 1930, the NSU team won the big gold medal with the same car. Since automobile production was discontinued, there was unfortunately no more talk of automobile successes in motorsports later on. NSU did not participate in motorbike racing again until the Englishman Walter William Moore brought one of the best English racers, Tom Bullus, to Germany. At the same time, a new 500 cc supersport machine had been developed by Moore. On 29 June 1930, Bullus won the Grand Prix for motorbikes on the Nürburgring with it – the spell was broken. From now on, NSU was a power in this class that seemed unbeatable. After his first triumph with the same machine, Bullus won the Solitude Race, the Eifel Race, the Klausen Pass Hill Climb, the German Mountain Grand Prix, the Gaisberg Race near Salzburg and the Nations Grand Prix in Monza. He thus became one of the most successful racing drivers ever. The modified machine also proved its worth in reliability and off-road tests. The bevel engine and the excellent road holding due to the cleverly chosen centre of

gravity made the SS 500 a winning motorbike, no matter where it started.

In 1937, the machine was fundamentally revised for the first time, with the success that Heiner Fleischmann became German champion in his class that year on a 350 NSU that had been prepared in this way and produced 36 hp. In the following year, the new compressor engine created by the now chief designer Albert Roder – Moore had left the factory in the same year – was to be used in the sidecar class. The plan fell through because in the same year the sidecar races were no longer held due to several serious crashes. Now Roder turned his approach into a supercharged twin for the 350 cc class. The 2-OHC engine immediately produced 44 hp.

The war eventually brought all further development work to a halt.