right, but let's assume that whoever owns the bike is A) not going to want you scraping part of the frame bare and B) not want you hacking away at it with a knife (nor let you take it to the lab to put under the spectrometer).

here are photos of the two bikes that got me scratching my head.
in the end, I figure it was just the frame cosmetics that confused me (because the frame sticker on the Scandium model is pretty clear.)

http://picasaweb.google.com/lugwork/TwinMerckxes#

But I expect it is as easy to slap a "Titanium" sticker on some frame as it is to slap a "531" sticker on. So, if you don't want to trust the stickers, how do you know?

was there any rhyme or reason to their paint schemes? or did they probably do their coffee mugs in the same patterns that week?