The year was 1916 and Danish engineer Jørgen Skafte Rasmussen founded a factory in Zschopau, Saxony, Germany, to produce steam fittings. That year he attempted to produce a steam-driven car he called the DKW. That was followed in 1919 by his first two-stroke gas engine.
He put a slightly modified version of this engine into a motorcycle and called it Das Kleine Wunder — "the little marvel.” This was the beginning of the DKW brand: by the 1930s, DKW was the world's largest motorcycle manufacturer.
They made cars and motorcycles, and in 1932, DKW merged with the brands Audi, Horch, and Wanderer to form Auto Union. The four interlocking rings are not representative of the Olympics, but rather of the four manufacturers that merged. After World War II, Auto Union moved to West Germany. Auto Union came under Daimler-Benz ownership in 1957 and was purchased by the Volkswagen Group in 1964.
The Audi company name is based on the Latin translation of the surname of one founder, August Horch. "Horch," meaning "listen" in German, becomes "audi" in Latin. (That’s also where the english term “audio” comes from.)
Before all this happened, during the late 1920s and early 1930s, DKW was the world's largest motorcycle manufacturer. In 1931, Ing Zoller started building split-singles and this concept made DKW the dominant racing motorcycle in the Lightweight and Junior classes between the wars. This included off road events like the International Six Days Trial (ISDT) where the marque scored some considerable inter-war year successes alongside the Bavarian Motor Works (BMW). At the same time, the company also had some success with super-charged racing motorcycles which because of their light weight were particularly successful in the ISDT.
The split-single ("Doppelkolbenmotor" to its German and Austrian manufacturers), is a variant on the two-stroke engine with two cylinders sharing a single combustion chamber. The split-single system sends the intake fuel-air mixture up one bore to the combustion chamber, sweeping the exhaust gases down the other bore and out of the exposed exhaust port.
The rationale of the split-single two-stroke is that, compared to a standard two-stroke single, it can give better exhaust scavenging while minimizing the loss of unburnt fresh fuel/air charge through the exhaust port. As a consequence, a split-single engine can deliver better economy, and may run better at small throttle openings.
A disadvantage of the split-single or “Twingle” as it was called is that, for only a marginal improvement over a standard two-stroke single, the Twingle has a heavier and costlier engine. Since a manufacturer could produce a standard twin-cylinder two-stroke at an equivalent cost to a Twingle, it was perhaps inevitable that the latter should become extinct.
However, from the 20’s to the 70’s, DKW and the Austrian manufacturer, Puch, had many successes with Twingle engines. Sears marketed considerable numbers of the Puch SGS split-single fitted with both these innovations as the "Allstate 250" or "Twingle" in the US.
Meanwhile, The motorcycle branch of DKW produced famous models such as the RT 125 pre- and post-World War II, and after the war with production at the original factory in GDR becoming MZ it made 175, 250 and 350 models.
As war reparations, the design drawings of the RT125 were given to Harley-Davidson in the US and BSA in the UK. The Harley-Davidson version was known as the “Hummer,” while BSA used them for the “Bantam.” IFA and later MZ models continued in production by DKW until the 1990s, when economics and environmental regulations brought production of the two-stroke to an end.
Other manufacturers copied the DKW design, officially or otherwise. This can be seen in the similarity of many small two-stroke motorcycles from the 1950s, including from Yamaha, Voskhod, Maserati, and Polish WSK.
DKW was once the world’s largest motorcycle company, and a major building block of some of today’s most successful companies. The car branch, Audi, is one of the largest luxury companies in the world. August Horch and Jørgen Skafte Rasmussen and these other early pioneers may not be as famous as Henry Ford or the Dodge brothers, but they are integral to the origin of motor vehicles too. And now you know the rest of the story.
Another storied European Motorcycle brand is NSU. Once called "Neckarsulm Strickmaschinen Union," (Neckarsulm knitting machines … remember Suzuki started as a knitting machine company too!) the company eventually shortened its mouthful of a name to NSU and became one of Germany’s most famous marques along with BMW and DKW. Annual production grew to more than 350,000 units in 1955, making NSU one of the world’s largest manufacturers of two-wheeled vehicles at the time.
But by then, the company was already on its way to losing the distinction. Through the 1950s, NSU became increasingly preoccupied with developing the Wankel rotary engine as well as a line of automobiles. Motorcycle production ceased in 1963, and Volkswagen/Audi swallowed the company by the end of the decade. In 1969 Auto Union GmbH amalgamated with NSU Motorenwerke AG.