This page lists brand names beginning with the letter "O" for which only an historical precis is available. See also the List of German Motorcycles.
Oberle
1927-29
Singen-Hohentwiel, Hegaustraße 9
Motorcycle racer Eugene Oberle built machines using Villiers 147cc and 172c two-stroke engines.
An example has been displayed at Oldtimer Museum Meßkirch.
Source: Tragatsch p234, motor-hist-foto.de.
Oberwetter
Manufactured by Vahle & Oberwetter of Bielefeld, 1921-1942
Initially a producer of frames and chassis components, the partnership ceased in 1925 and Heinrich Oberwetter began building complete motorcycles using mostly Kühne engines of up to 500cc until at least 1928. Component production continued until 1942.
Three-wheeled vehicles for the disabled ("Krankenfahrstühle") were produced from around 1927 until at least 1938.
Sources: GTU Oldtimerservice, Automobilia 85-45.
Ocra 1923-1925
Odin
Manufactured in Schwabach by Karl Ludwig Konrad from 1923 to 1925.
Built 125cc two-stroke motorcycles with a two-speed gearbox and block brake on the rear wheel.
Source: de.wikipedia.org
ODA
Oda Werke AG, Hamburg 1925-1926
Built lightweights and bicycle attachement engines of 183cc
Source: motor-hist-foto.de
Ofran
1923-1925
Built motorcycles using a 425cc three-port two-stroke of their own manufacture.
Source: Tragatsch p236
OGE 1921-1924
OHB
1927-28
Otto Hoffmann designed this motorcycle which used a 490cc JAP sidevalve engine.
Source: Tragatsch p237
OM
1923-25
Using JAP 173, 346 and 490cc sidevalve and ohv engines, the firm produced motorcycles in limited numbers.
Source: Tragatsch p238
Omnia
1931-33
Lightweights powered by Villiers 98cc and 147cc two-strokes, and also Bark engines (Tragatsch suggests the Bark was built by Imperia at Bad Godesburg, but this may be an error)
Source: Tragatsch p239
ORI
1923-25
Otto Rierl & Co., Präzisionswerk, Brake in Westfalen
Built lightweights with 145cc 3.5ps two-stroke engines mounted horizontally.
Sources: Tragatsch p240, motor-hist-foto.de
Original Nofa 1960s
Oruk 1922-1924
Ortloff
Manufactured by Ortloff Automobil AG, Berlin, 1924-1925
Believed to have used engines from Cambra and Alba of 185cc to 198cc mounted in frames from the Berlin-based Hugo Gruhn firm.
Source: GTU Oldtimerservice
Osning
Manufactured by Osning-Fahrradbau Wilhelm Wellerdiek. Brackwede Bei Bielefeld
Their 1939 bicycle catalogue lists one motorcycle, a 100cc model with pedals.
Source: nw.de
Otto (OWM) 1921~1930
OWB Sidecars 1950s
Rarer German Marques