The smallest pit bikes, such as a 50cc can go about 25 mph (or much less if they've a limiter), whilst the quickest designs can go 60+ mph. The best pace largely will depend on how strong the engine is and what the transmission and gearing are set up for. https://go-off-road88147.angelinsblog.com/37204147/the-smart-trick-of-pit-pit-bike-that-nobody-is-discussing