Get the 7.2, I have a 7.1 and I instentaly upgraded most of the compents to that of a 7.2 or 7.3. If you go any higher, you comming from the bike you have you wont notice much of a diffrence. Basic diffrences bettween the 7.2 and 7.1, that I noticed are, better grips, better tires, metal pedals not the rubbery plastic stuff, the seat is diffrent but steats are persanal perfrence and I think the shifters are better but I am not sure.