Thank Robow,
I did test ride the 57 at my Lbs, but since I have no previous experience with dropbars...except when I was 7 years old (I had a beautiful orange eddy Merckx bike!)
But it looked and rode fine. That said, I just rode it for 15 min so it's not really enough to have a good idea of the fit on a long ride. They didn't have the 54 to compare with the 57, but I believe it will be too small.
I checked their geometry at the trek web site, and indeed the top tube is short for a 57.
Strange they have all their bike in size 54-56-58 but not for the 520.
so I will probably go with the 57 and get a shorter stem if needed.
and a brooks b17 of course!
But I'm still looking at the lht but can't find one to test.
youcoolele