>Just heard from a knowledgeable person that perhaps Simplex did not
>pre-date Campagnolo with double parallelogram rear der. I could be
>wrong, I have no data on hand to support that idea, just thought I
>remembered that. Will happily defer to someone who knows this
>detail...?
The first parallelogram derailleur in widespread use was Nivex (1938)
Campagnolo was the first who adopted a Nivex to mount on the rear dropout, making it suitable for racing (but inverting the parallelogram, and making it move away from the cogs as the cogs get smaller, the opposite of what you want). (1949)
Simplex was the first with a spring-loaded upper pivot, which eliminated the changes in geometry associated with front shifts. (1961 or 1962)
Suntour was the first with a slant parallelogram, which restored the path of the Nivex, getting closer to the cogs as it travels to a smaller cog. (1960s)
Shimano was the first who combined the expired patents of Simplex and Suntour, creating a slant parallelogram derailleur with two spring-loaded pivots. (1985?)
There was an article "Milestones in the Development of Parallelogram Derailleurs" in Bicycle Quarterly almost seven years ago, which has the exact dates, Rebour drawings, background, etc. It's available online at our "Samples" page, together with the history of the first Campagnolo Grand Sport - see
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Jan Heine Editor Bicycle Quarterly 2116 Western Ave. Seattle WA 98121 http://www.bikequarterly.com
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