This 501 OS (Ohv, Sport) model was produced between 1932 and 1934. After 1934, it underwent some modifications and became known as the 501 OSL (Ohv, Sport, Luxury), with the latter model being manufactured between 1935 and 1939, with a total production of 8,000 motorcycles.

The NSU 500 OS derives from the racing motorcycle – NSU 500 SS (Super Sport), a true champion, which was ridden by the Englishman Tommy Bullus.

This motorcycle became better known as the NSU “BULLUS.”

This motorcycle is very similar to the 1927 Norton Model 18 with overhead valves, as its designer, the Englishman Walter William Moore, left Norton in 1929 to join NSU, where he remained until 1939 (the beginning of World War II).

Because this motorcycle had a very high price for its time, its main buyers were families of Jewish origin, many of whom disappeared during World War II, with around 12 remaining between the Czech Republic and Poland, 1 in Germany, another in Italy, and this one in Portugal.