Originally Posted by
katsup
Yes, the higher the number in the 7xx series the better the frame and components. The 750 and 790 are at the top, 790 is better when comparing the lugged frame years due to it having a cassette.
A 90-93? 520 had the best frame (same as multitrack) and components, but came with a drop bar vs flat.
Back when I was looking at MultiTracks to buy, I put together a little matrix on the various frame materials from the Trek catalogs on vintagetrek.com.
Link here.
Definitions for some of the shorthand:
CM = Chrome Molybdenum
HT = High Tensile
DB = Double Butted
TIG = Tig Welded (vs. lugged)
TT = True Temper (brand of steel)
In some years, the 730 and 750 appear to use identical frames, and in others, they're different. Sometimes the 720 is a frame upgrade over the 700, and sometimes it's not. As the information is from their sales catalogs or technical manuals, accuracy is only as good as those. The literature was often times not exactly clear on what models used what materials, or if one was an upgrade over another. But for what it's worth...