That radial engined motorcycle looks interesting, but how 'bout a ROTARY engined bike!!! 
Ps. I assume someone can get rid of the 100 or so "posts" from ebay crawler, PLEASE! They are very aggavating, and, I am sure, break some forum rules. |
Back in the mid 1970s Suzuki built a single rotor water cooled bike the RE5 which was approx 550cc capacity, it was a large & complex machine for a mere 550 its physical size & weight elevated it in to the 750/1000cc class with fuel consumption & price to match.
I test rode one when they first hit the UK & found it to have a high centre of gravity, this combined with disc brakes that did not work in the rain caused some concern on my test ride, its performance was only equal to a normal 4 cylinder of equal capacity though it felt smoother & more relaxing in a straight line, the exhaust note sounded like a cross between a motor boat & a well controlled fart, the model only lasted until 1979.