BMW's longest-running motorcycle models tend to be identified by a single letter for their model names; for example, the K, R, F and G series. The company's first motorcycle was the R32, which was first produced in 1923.
BMW's R series began as a motorcycle for general use but was adapted for military use by the Third Reich during World War II. The terms of Germany's surrender forbade BMW from producing motorcycles until 1947. The company's plans and blueprints for the R series had been entirely destroyed by Allied bombing during the war, so they had to remake the series from scratch by reverse-engineering older models.
BMW's R series has continued through many different model types into modern times, with the first keyless model, the R1200RT, debuting in 2015. The company introduced its K series in 1988 and its F series in 1993, both of which have sport designs and have models in production, as of 2015. The off-road G series was introduced in 2006. The company has also produced some special models for competition, such as the HP2 Sport, which is an R1200S modified for endurance races. The company also manufactured the S1000RR sport bike specifically for entry in the 2009 Superbike World Championship.