The Aprilia RS50 Max speed is 65mph. (Im 135pounds). It takes a long distance to reach this speed!! You will shift 3to4 times to get out of an intersection.. Its about 10mph per Gear.. Lower in the first 2Gears.. Will the Bike go UPHills 50mph.. It Cant, 30 to 40Mph It can, It also Depends on the Degree of the Hill.. Anyone Who Says the Apilia RS50 Can 90Mph Stock is telling lies!! You will find out when you Buy it.. With a 75cc Kit & carb, it will go 80Mph.. But That is Maxed out on the Rpms, This is with a Aero Race pipe, You Can gain a Little MPH by Changing the Sprockets.. Its a Nice Bike.. I Does not have Power!! 5.32HP @ The wheels.. 75cc Kit will push It Up to 10HP.. The Most I have Seen on a "REAL" Dyno was 14hp. & The bikes total $$ to Get it to that,about $3000. to get it to that level.. Good Luck!! Test Before you Buy.. Or Go to Apilia.com & e-mail them, they can give Good info!! I have Been Riding the RS50 FOR 2yrs. Im Still hoping the RS250 Gets Fuel injection, This Could help it, make it to the USA Streets!!