Altogether 5,000 exemplars of the BMW R 20 were manufactured from 1937 to 1938. The machine was propelled by a 192 ccm engine with an output of 8 HP.
The BMW R 23 was manufactured from 1938 to 1940. It replaced the R 20. Altogether 8,021 exemplars were made. Outwardly, it was nearly identical compared to the R 20. Only the engine was enhanced to 247 ccm and an output of 10 HP.