In 1919, as the demand for weapons parts declined after World War I, Neumeyer became the sole proprietor of the company, and two years later he diversified into the construction of motorcycles.

The series encompassed models from 200 to 800 cc displacement and was a major success, increasing Zündapp's market share in Germany from 5% in 1931 to 18% in 1937.

The Zündapp KS600, first released in 1938, had a 28 hp (21 kW) horizontally opposed twin cylinder engine with overhead valves displacing 597 cc (36.4 cu in).

The Zündapp K800 had unit construction, flat-four engines with shaft drive (a layout adopted by Honda for the Gold Wing in 1974) and were the only 4-cylinder machines used by the German armed forces in World War II.

Zündapp experienced enormous success in off-road motorsports winning thousands of Gold-Silver and bronze medals, many Championships.

The American rider Dave Ekins won an overall victory at the 1967 Greenhorn Enduro aboard a 100cc Zündapp, defeating competitors on much larger motorcycles.

That made it much easier especially for the Japanese manufacturers to break into the previously protected market as they could easily downsize the 125 cc engines.

A dedicated factory was built at Ranipet near Madras (now Chennai) in the early 1980s to manufacture small, lightweight two-stroke motorcycles to be offered along with their flagship Royal Enfield Bullet.

It had five-speed gearbox, a hydraulic Brembo disc brake and a sleeveless hard chromed cylinder barrel, all were a first on a motorcycle in that country.

The newly owned company subsequently produced e-bicycles and later revealed a new motorcycle concept, the ZXA 500 Adventure, at the 2022 Intermot Show in Cologne.