[2] In 1919, BMW designed and manufactured the flat-twin M2B15 engine for Victoria Werke AG of Nuremberg.

The engine was also used in the Helios motorcycle built by Bayerische Flugzeugwerke, which was later merged into BMW AG.

Bayerische Flugzeugwerke also manufactured a small two-stroke engined motorcycle, called the Flink, which was not successful.

Upon completing his assessment, Friz suggested to Popp that the best thing that could be done with the Helios would be to dump it in the nearest lake.

More specifically, Friz condemned the Douglas-style transverse-crankshaft layout, which heavily restricted the cooling of the rear cylinder.