Imagine you're relaxing on a mountaintop in 1974 when you hear a distant engine growing nearer. It revs so high, it sounds like an approaching helicopter. Or perhaps a tiny, high-pitched jet. Finally, ...

Unveiled in 1973, the OCR 1000 was the world's first production motorcycle to feature an automotive-derived, twin-rotor engine, and its creators dubbed it the finest, most technologically advanced ...