I had a 1986 Cannondale SR400 that had its seat stays arc after (presumably) heat treating. Looked fine from the side, "down the line" sighting revealed the curve. Rode fine of course. I now have a 1991 SR800 and the down tube is banana'd when you sight down from the head tube to the BB. Lol. Unnoticeable from a side view, and of course as the paint is nearly flawless and there are pretty parts on it, I couldn't care any less! I still want to test ride it though, but we've had some wacky weather lately and now there's a bunch of snow on the ground and it doesn't look like it will abate for at least a week. Temps out of the 20's would be nice, too.