I had a bike shop fit me on a 13 inch Trek 7.3 originally. I bought one a couple of years back and had to get a new bike due to the fit being all wrong. I experienced a lot of back/leg/neck pain - as well as aluminum buzz that made my hands go numb. Ultimately it was too small for me. I'm 5'3'' My LBS told me a 13 inch should fit a 4'11'' - ish woman. Hoo-boy. I now have a 520 and an Aurora both fit differently but fit well and I adore them both. The Aurora was a graduation/xmas present. The 520 was my re-placement bike.