BMW's roots go back to early aviation

Among the European bikes on display at the National Motorcycle Museum in Anamosa, Iowa, are Ducatis, MotoGuzzis, BMWs, Jawa/CZs, Husqvarnas and even NSUs. The museum is a great place to recall designs of the past - perhaps some of your past motorcycles.

The National Motorcycle Museum is about 3½ hours west of Chicago - a nice ride. This time we focus on a BMW offering from the late 1930s now on display there: the BMW R12.

The BMW R12 and R17, both introduced in 1935, used unique pressed steel frames and may have been the first production motorcycles with hydraulically damped telescopic forks. They continued BMW's stylish black-with-white pinstripes graphics, a design that lasted for decades. Classy cloisonné badges employed the rondel, reminding us of BMW's aviation origins.

In roughly the same time period, Harley-Davidson brought us its first 61-cubic-inch OHV twin, an interesting comparison.

BMW, or Bavarian Motor Works, was formed about 1916. Its first products were aircraft engines. BMW's "boxer" engine layout worked for aircraft, keeping the cylinders exposed to cooling airflow. This layout also worked well for motorcycles and BMW built its first in 1923.

The in-line layout (crankshaft in line with the motorcycle's length), made it a natural to use a direct connection between the engine and transmission, then an open drive shaft to the rear wheel. There was no primary or final drive chain to maintain. In a sense, BMW's time with aviation designs set its path, with few deviations, for the next 75 years.

Now BMW uses in-line and transverse sixes, fours; transverse twins and singles; and even belt drive! But boxer twins satisfy the BMW traditionalists, even liquid cooled, and remain a mainstay in the model lineup.

With the introduction of the R11, BMW began using a new frame made of left and right pressed steel halves riveted together. With common use of sidecars, previous frames sometimes fractured. With the R12 also came hydraulic front suspension, though, as with most other makers, a sprung seat for the rider and passenger were all that was offered to damp bumps at the rear of the motorcycle.

A version of the R12, often fitted with a sidecar, was among machines that served Germany's needs during World War II.

According to Wikipedia, another example of a surviving BMW R12 can be found in the Museum of Military History in Vienna, still bearing its original camouflage. Many R12's remain in service with private collectors.