The 1934 BMW R7 prototype:

Back in 1934 this unique prototype was created by design engineer Alfred Böning, years ahead of it's time it was sadly never taken into production. The only prototype was crated and stored untill 2005, when the badly rusted and only 70% complete prototype was rediscovered and fully restored. There is supposed to be only one of these bikes, but I have found pictures of 2 slightly different versions, perhaps the other one (in the picture below) was the original 1934 version?

Some tech details: This bike probably had the first telescopic forks used on a motorcycle, cylinder heads and cylinders were one piece, eliminating the need for head gaskets. The frame was stamped steel plate, there are no frame tubes like in more modern frames. The engine had a one-piece forged crankshaft and had carbs with accelerator pumps. Allthough the bike had "only" 35 horsepower, it weighed only approx. 170 kilograms and was able to do 90 mph, which made it a real superbike in 1934!

Some more pics of the restored version: