Think of rotary engines, and you probably think of Mazda. But in the 1970s, two companies put those silky-smooth Wankel rotary engines into motorcycles. One was Suzuki, with the RE5; the other was little-known Hercules of Nürnberg, Germany. The machine above is the rare Hercules W2000, powered by a single-rotor Sachs-made engine. The W2000 was produced in small numbers from 1974 to 1977, and when production finished, Norton used parts of the tooling to make its 1988 Commander. The motorcycle shown above is one of the few remaining W2000s on public display: you can see it in the Deutsche Zweirad- und NSU-Museum in Neckarsulm, on the site of the former NSU factory.