1975 "Wankel 200" Rotary Engine
The idea of the rotary engine, developed by Dr. Felix Wankel, proved irrisistable to manufacturers the world over. Many of them invested heavily in research programs that never got to production. Sachs-Hercules pulled it off, however, and managed to put a rotary-engine bike on the market. Wonderful in theory, the rotary engine proved unsatisfactory in practice and the venture was abandoned before the Eighties.