Zündapp Excerpted directly from Wikipedia
Zündapp was founded in 1917 in Nuremberg by Fritz Neumeyer, together with the Friedrich Krupp AG and the machine tool manufacturer Thiel under the name "Zünder- und Apparatebau G.m.b.H." as a producer of detonators. 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 company folded in 1984.
The first Zündapp motorcycle was the Z22 in 1921, the "Motorrad für Jedermann" (motorcycle for everybody), a simple and reliable design that was produced in large series. Zündapp's history of heavy motorcycles began in 1933 with the K-series. They introduced the closed engine case, a novelty at the time. (The "K" stands for "Kardanantrieb", i.e. enclosed driveshaft with two universal joints, a type of drivetrain, which these models featured.) 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. From 1940 on, Zündapp produced more than 18'000 units of the KS750, a sidecar with a driven side wheel and a locking differential for the German Wehrmacht.
After World War II, the company gradually shifted to producing smaller machines, for instance the "Bella" motorscooter, still a relatively heavy machine for its type. The last of the heavy motorcycles, and incidentally also one of its most famous models, was released in 1951: the KS601 (the "green elephant") with a 598 cc two cylinder engine.
From 1957 to 1958 the company also produced the Zündapp Janus microcar.
In 1958 the company moved from Nuremberg to Munich. Subsequently, the company developed several new smaller models, gave up the development of four-stroke engines and only produced two-stroke models. Initially, Zündapp scooters and mopeds sold well, but later sales declined, and in 1984, the company was bankrupt and closed.