Weight has nothing to do with top speed. Top speed is a factor of horsepower and frontal area. Those stock bikes are capable of 180-195mph. I did 175mph many years ago on my trusty steed ZX1100 and I can say that I felt safer doing those speeds in a bike than a car. It's a mindset, go figure.unless that kid weights 50lbs plus a few G's in mods, that bike won't do 205mph