Nice shot...I would talk some history: BMW was producing reliable shaft driven motorcycles that the US Military thought would be perfect for use in combat. One problem, BMW was a German company. So, to solve this problem, the Army told Harley Davidson to basically steal the German maker's designs and build a version for the US to use.

The result was a success but after the War Harley reverted to its chain drive ways. The WWII surplus bikes were popular after the War and many returning GIs snapped them up and hit the road.