Anyway, something has happened over the years and the bottom of the stem is damaged/ground away and it won't clamp properly any more. The stem is the type with a wedge at the bottom. Is there someplace I can get a stem for this bike? I've read the Sheldon Brown pages about how I may have to sand a new stem slightly to get it to fit, but I'm trying to find a place where I can buy one - I don't see any on Amazon. Thanks in advance!