Converting a short cage rear derailleur to a long cage derailleur Is it possible to convert a short cage rear derailleur (for example the Huret Svelto) to a long cage derailleur by just taking the lower cage and replacing it by a longer one?
Yes, if the derailleurs are the same model, and you can get all the parts, (which isn't usually a straightforward process) youcan convert from short cage to long cage.