My buddy recently bought a frame of some dude on craigslist, and although neither of them were exactly sure what it was, there was still the 531 sticker on it and that's mostly what sold him. However, he told me recently that when he took it in to a shop, the mechanic told him it wasn't Reynolds and he paid way too much. The mechanic then tried to explain it all to my buddy, but something was lost in translation and he never got the whole picture. So, I'm curious.
How does one exactly tell if it's 531 tubing or not? Got any pictures showing differences? Thanks