I have 180cm and the recommended size for me is 58cm or so, which i already have, a classic Peugeot racing bike. Works relatively ok but i found that i ride it better when i'm leaning forward and keep my hands on the lower side of the handlebars. And now comes the problem, i'm thin and i need more power than i have to ride this bike fast and long. However, the only bike i found to buy in my country and also to like it, is a 54cm with the reynolds 531 frame but i can't test it as it's not in my city (i do plan to test other bikes of 54 if i can find but for now i didn't).
So my question is, is there any reason i should not buy it? From the way i see things it shouldn't be any problem if i can pull the sit high enough. The handlebars are already a little lower which should be good. If i look to professional riders they also seem to have a smaller bike comparing to their body size, but this Peugeot is like controlling me.