Well Andy I am 5ft 9.5 inches tall but long legs relative to torso. I would say no taller and ideally shorter than me. Possibly quite a bit shorter would still fit well someone more evenly proportioned. Its 52cm top tube which I would say approximates better to a general small than medium classification. Let me know if you're interested in looking at/ trying it and I'll get it to a club night. Its enabled me to get a 21 for a 10, a short 54 for a 25, and a 1:57 for a 50. By comparison I have never managed to average over 24mph on any solo ride on any road bike that starts and finishes in roughly the same place.