1938 Dürkopp light motorcycle with 98cc Sachs engine. See also: Dürkopp bicycle with Lutz engine
"In Bielefeld, Germany, during the middle of the 19th century, the industrial revolution had turned the city into a major textiles location. Imported sewing machines, mainly from the USA, were expensive to buy and hard to service. Two mechanics, Baer and Koch, recognized the opportunity and started the first sewing machine factory in Bielefeld . In 1865, Baer decided to start his own operation. Koch continued trading under the name of Koch & Co, and by this time, he employed two sewing machine mechanics: Dürkopp and Schmidt. Dürkopp had already designed his first sewing machine in 1861, and in 1867 together with Schmidt, he started his own company known as Dürkopp & Schmidt. Dürkopp & Co, as the company was called after Schmidt’s departure, was the first enterprise to start seeking new markets with the manufacturing of bicycles.
The new product line sold very well. Inspired by this success, Dürkopp started manufacturing cars, trucks and other forms of motorized transport at around the end of the century. At the end of the 1920s, the world economic crisis forced Dürkoppwerke AG, the name of the company after the death of its founding father, to give up car production, which in any case had not been a great success. Like most other German manufacturers in the 1930′s, Dürkopp marketed lightweight motorcycles with Fichtel & Sachs engines." (based on www.oldbike.eu article)