you've probably already made ya mind. But I have a katana and got 55 out of it just derestricted with all standard parts and soon to put a new sports pipe on it to see how it goes. Another boy who lives near me has the same bike just a different model which only has different panels on it and he got 71mph out of his but don't know what he done to it lol
Uranus? as he seems to be chatting out of his. japs make good sports bikes not peds (and what are these fastest cars they make and the ones that if they wasn't built would have left us in the dark ages? and a hayabusa is the fastest road production bike in a straight line, not the fastest.). 50cc mopeds are slow in general and a katana is no different if any thing its one of the worse. good choice with the rox mate, as the traditional Suzuki colours are the closest a katana comes to being a good jap bike