Originally Posted by chombi

i know cannondale frames (aluminum, of course) had some heat treatment curvature sometimes present in their frame tubes back in the 80's, as i remember helping my brother find a black lightning frameset with the least amount of curved tubes on it from a dealer's stock back then...
Not sure what type steel tubing your bike has (columbus spx?), but i'm wondering if it has heat treated tubing that does the same thing???