Originally Posted by
sykerocker
By the way, to those not conversant on Trek's of this vintage, the model number is something of a code to the frame geometry. The first digit is the model level (higher is better), the remaining two have a lot to do with frame geometry and purpose of design.
x20's are touring bikes (the Trek 520 is an absolute classic of this genre). x60's are racing, the 460 was the amateur level (I've got one - geared - and absolutely adore it), 560's 660's, 760's keep getting better in tubing as you go up the ladder, all frames are made with a fast handling geometry. The 460's have the added advantage of not having come with shift lever braze-ons, keeping the clean lines without unnecessary hacking.
It's not the second digits that determine class, it's usually the first. 5xx, 6xx and 7xx are all touring bikes. The 520 needs no introduction, the 720 is even more epic, and almost impossible to find. I have a 610 that has chainstays longer than even the Long Haul Trucker, and the 600 I posted earlier is still rather touring in geometry.
4xx are usually of lower quality, although I would kill for a 420L for my girlfriend (do you know how few mixtes were made with nice tubing?), although they were still quite nice. They had a more generic 'sport touring geometry, even the 420's
I think X00's were framesets that were sold without being built up. Eh, it's hard to find a pattern in the madness, just bookmark
http://www.vintage-trek.com/