Got hit-and-run by a car here in NYC while on my Columbus SL 80's Ciocc San Cristobal. I'm ok, but my bike might not be. When I got home, I noticed one single tiny ripple in the paint about 1.5 cm wide on the top of the top tube just behind the head-tube lug. The direction of the ripple runs perpendicular to the top tube and it is no more than a millimeter in thickness. The geometry of the bike has not changed, and I suspect that as far as this type of damage goes, this case is not so bad. But, I still would like to know that its just the paint and not the tube that is affected. What are my options in determining if this is a crack or a just paint ripple? Am I left to somehow strip the precious original Italian paint where the ripple is? Sandpaper? What would you do? Thanks in advance.
I am not sure. One way is possibly to scrape the paint off in that section? If you don't want to damage the paint, you could possibly remove the forks and stem - and if your steerer tube allows for access to the top tube you may be able to feel for any cracks from the inside of the frame. But it would be best to take it to a bikeshop/frame builder to make sure.
Maybe take a few more photos from different angles - such as a side-on view so as to provide more detail. To me it looks dented, because the light is reflecting from different angles before and after the line. How is the bottom tube? Usually these snap and bend when you collide front on. Did the handle bars twist and hit the frame hard?