I recently gave a talk to the Cheshire Section of the V-CC on “Simplex Racing Gears“, which was very much an overview of the different models of racing derailleurs from the 1930s through 1980s. I make no claims of scholarship or thoroughness with this – it was meant as a general interest piece with pictures of riders and bikes as much as of gears. If you have anything to add or correct, please send it in and perhaps we can develop a useful resource for people interested in Simplex.