At the risk of exceeding my 3 per day limit and not being vintage: can anyone tell me, preferably onlist, what attempts were made in the past at belt drive on bicycles. More importantly, how would the best of today's toothbelt drives match a chain drive energy loss wise. Because the ideal chainline is a straight one (anyone to contradict me on this one ?) , and were a energy-efficient beldrive to be feasible, any manually commanded expanding rear wheel pulley wheel (see mobylette automatic transmissions for the general idea) would give the ideal drive system. An expansion factor of 2.2 on the back pulley mech would give a more than large enough ratio choice.
If a belt drive is not a possibility, why has nobody attempted a straight chainline variable ratio drive with a different type of chain then the standard bicycle chain (the possibilities for expanding a back "cog" are innumerable). Or have they. They probably have, the amount of left by the wayside innovation in early cycles is probably greater than in any other field of transportation. To clarify this, I have yet to see an "innovation" in modern cycling that was not tested or produced at one point or another in cycling history, then dropped for reasons of cost or else.
Nick March, Mont de Marsan, Landes, France
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