Originally Posted by froze

It looks like a 412 or 515 which is a sport model which has a frame geometry between a racing frame and touring frame-but I might be wrong and the year would be between 1979 to 83. The Ishwata 022 was their 2nd best...if lightness is a determining factor of what is best, frame; their best was Ishwata 021; those numbers represented the tube thickness. Ishawata argueably made the best tubing in the world though I'm sure there are many here that would dispute that. Ishwata 022 and 021 was as light as light as anything Reynolds and Columbus made, but Ishawata had the advantage of being stiffer-not as flexy.

The serial number should be stamped on the bottom of the bottom bracket then take that number and go here: http://www.vintage-trek.com/SerialNumbers.htm