in totally stock trim with everything in 100% working order expect a SOLID 30mph out of it. with a little work to it, even with the stock carb and exhaust still expect 30mph, but more torque. the limiter on the V1 is the exhaust and carb. a good exhaust and a 14-16mm carb will get you well past 30.
the 75cc polini kit is a great part, well made, that will get you into the 40's no problem.