Why is my Bike so Slow? How to Rev it Back Up One of the attractive things about owning a pocket bike is the adrenaline rush that speed can bring on, feeling the wind whip around you whether it is alone on a private track or in the middle of a race. Pocket bikes were built to race, they were built for speed. A pocket bike is a miniature version of a Grand Prix moter bike, so this makes sense. These bikes can be customized to go 50, 60, or even 70 miles per hour!! The current world record, in fact, is at 72 mph. So what happens if you start your bike, and it just wont hit those speeds you know it should be? What if your pocket bike is going too slow?