Originally Posted by Eggman84

It did not go out of the factory with Tiagra STI shifters; all Trek 520s of that era used barend shifters. Also Shimano introduced Tiagra in 2011, starting with 4400 at 9 speed. Per Trek catalogs, 9 speed cassettes were not introduced on the 520 until 2001. So, if based on color it is a 1999 frame, then someone updated both the shifters and cassette before the original purchaser bought it Not unheard of for a bike shop to change components. Maybe it was languishing on the floor and they though putting on STI shifters and going to 9 speed would move it out the door.. You can actually contact Trek with the serial number and they should be able to tell you when it was built. Or use teh vintage Trek web site to identify it Vintage Trek Bicycle Frame Serial Numbers, bike


In any event it is a great bike. I think 9 speed RDs and cassettes are great for touring, For my taste, its geared a little high but you can change the crankset to a MTB style and use an older 1999 or earlier MTB front derailleur (before they made the inner plate so tall).