The geometry changed some over the years with the MultiTrack series, so it's best to consult the technical info from Trek to determine what years and sizes may fit you best. There's generally at least one major change -- I think the frames changed from lugged construction to tig welded in 1993 (or so) and I think some of the geometry specs changed at the same time. There may be other differences throughout the years as well, so it might be best to go through year by year and make some notes about what you want to focus on in terms of a used bike search.