I had a 50cm kilo and it fit me well at 5'4" since I had long legs. I have couple other friends that are 5'7" 5'8" that also ride at 50cm and the frame fits them as well. I have one friend at 5'10" that has a 53cm and it fits him fine. Of the sizes youve given, I'd suggest that you get the 53cm if they are out of the 50cm.