Discussion of the Bowden Spacelander has been brought up but I never knew of the prototype having a dynamo, stored the energy and then released for uphills. Definitely ahead of the times.
British born Benjamin Bowden (1907–1998) originally designed the futurist Spacelander bicycle for the “Britain Can Make It” exhibition in 1946. Conceived
in aluminum, the dynamic form
featured a direct drive hub dynamo that stored the downhill energy and released it on uphill runs. The originally prototype for the exhibit was hand-made by the MG Auto Company (Morris Garage). Due to the expense of manufacture and 14 years later the bike finally went into production in 1960, when Bomard Industries of Grand Haven, Michigan contracted with Bowden to create the finished product. The final design streamlined curvilinear monocoque was produced in fiberglass and built-in headlight, taillights and horn were added. The Spacelander weighs in at a hefty 50 pounds and sold for $89.50. A number of bicycle manufacturers rejected the Spacelander as too exotic for mass marketing. Ultimately, Bomard Industries went of business and only 522 examples were ever produced.