Salty , I'm not sure you know this but the Urban is a much weaker stamped frame that is more likely to bend or break at the rear shock mount under stress . Plus the angle on the shock is greater on the Urban I am about 240 lbs and I have bent the frame on my Urban . Where as the regular Express is a tube frame and is in my opinion much stronger and it feels that way too . It also can be braced more easily . AJ is a big boy too so this may be a factor in his chose to build it . Now , if you take the nu50 motor and put it on the Express frame thats a different story . But thats here nor there .and one can do anything they want to given enough time . tools , parts skill experience and so on to do so . Just sayn man , I think he has both bikes and this is his first build so let him do what he wants . Lets not make this confusing for him . He can build an urban too . Later or whatever .
AJ , if you want to build an Urban motor or an Express motor I'm behind you all the way . No sweat bro
Salty , You are right tho it is nice to have a variator to tune on but for a first build thats just one more thing to worry about and to go wrong . I think that he should take one step at a time . Plus he can still use a lot of the performance parts on the Urban later if he wants .
Just my two cents . So I will shut up now .