BMW acted to simplify the system in the mid-1920s. The references to the number of cylinders and model series were abandoned. Now the only entry in front of the project number was to denote an engine (‘M’ = Motor), transmission (‘G’ = Getriebe), a frame for motorcycles (‘R’ = Rahmen) or a chassis for cars (‘F’ = Fahrgestell).
And this was how the first ever BMW motorcycle got its name. The frame for the new bike was given the project number ‘R 32’ when it was entered into the project list. The engine was christened ‘M2B33’, later shortened to ‘M33’. The transmission used in the motorcycle bore the designation ‘G 34’. The internal project number for the frame construction saw the motorcycle unveiled with the official sales designation ‘BMW R 32’. Initially, all the brand’s motorcycles were issued with their name according to this system, a product of the design organisation. In the public use, the ‘R’ stands for ‘Rad’, a short name for Motorrad (=motorcycle) at this time. Interestingly, many mistake ‘Rad’ for the other sense of the word – ‘wheel’!
The mid-1920s saw an enforced change to this designation principle. Up to that point each motorcycle had its own frame construction. Now the designers started using the same frame for several models, although these could be distinguished by the engine variant fitted. This development meant that the sales designation for the models could no longer be based on the project numbers for the frames. The ‘R’ was retained, but was now followed by a two-digit number that differed from the design designation.
Motorcycles were to be given new sales designations. A system giving the single-cylinder machines single-digit sales designations and the two-cylinder units two-digit designations was hastily introduced.
With the acquisition of the Eisenach vehicle factory in 1928 the decision was taken to separate the numbering systems for aero engine, motorcycle and car development. The National Socialist authorities oversaw an intensification of rearmament in Germany from 1933. In order to simplify the expansion of the Luftwaffe, the Reich Air Ministry apportioned fixed numbering systems to its various engine manufacturers. BMW was given the range between 100 and 199.