Originally Posted by MetinUz

I watched famous frame builder Chris Kvale spread my vintage Columbus Trek frame. He clamped the frame on a benchtop vise at the bottom bracket shell, ran a string from the head tube to the dropouts. He then proceeded pushing and pulling on the dropouts and measuring the string-to-seattube distance. It just took a few minutes, he then aligned the dropouts with a Park tool. He said this is the best way if you know what you're doing...