Put on your blindfold about frame sizes and give it a try (adjusting the fit). I rode a 58cm for 2 years and finally admitted it was too large after trying four stems and multiple position adjustments. I am 5'11" but my proportions don't work on this size frame. I was sure a 56 cm was what I needed and so was the dealer until he did a fitmaster fit on me. I ended up with a 54 cm Cervelo that fits like a glove.

Bob