54 is definately too big. I'd be on a 56 and I'm 6'1. The 58 works but doesn't offer me quite enough clearance for cross racing. My friend is about your height and on a 50 or 52 I think, or whatever they have that is close in that range. His girlfriend is about 5'10 and on a 54. Generally the rule for crossbikes is one size smaller than your road bike.