NSU 4 hp 2-cylinder motorcycle, 1920
Derived from the 3.5 hp military model, the 4 hp 2-cylinder of 1920 was belt-driven. It was fitted with modern foot rests, was painted black, had a green tank and all other polished parts were now in matt nickel. The first post-war 2-cylinder vehicle had an advanced front suspension fork, which greatly improved ride comfort. The wheel brake was replaced by an adjustable expansion brake. It also had a starter mechanism featuring a rearward acting starter crank with freewheel.