So, after a few long rides last summer to distant locations, my fiance and I are thinking of going on a few shorter tour rides this summer (1-2 nights overnight) - and possibly longer, in the future, if we like it.

As is, we'll be taking our '86 and '87 Trek 400s (yes, we both have basically the same bike) that we have set up with panniers and use mostly as commuters/utility bikes. However, I've also been looking around to see if I can set up some more serious tour bikes if we get into it.

I know the Trek 520 is a well-regarded touring bike (and came across an'86 listed on ebay), I went to look at the Vintage Trek brochures and saw that for '86, the Trek 400 (elance), Trek 520, and Trek 500 (tri) all look to have the same frames but somewhat different components. This seems off because the three bikes seem to be going after different audiences: 520 (touring), 500 (triathletes),and the 400 (the "sport" crowd).

Has anyone else noticed this? Do all these bike really have identical frames? Also, with the 42.5 cm chainstay, is this frame still a bit short for a touring bike (and Trek was just a bit off with its '86 520)? If they are the same and good, I might just consider putting some updated (touring) components on our old bikes. However, I want to see if anyone else has any thoughts/experience with this. Any ideas?