Most sportbikes will also easily surpass 120 miles per hour, which is the limit for most police cruisers. Bikes have superior maneuverability compared to cars. A sportbike can turn better and simply fit more places than a car. You just don't need the room a car needs. This makes it possible to slip out of the car's grasp quite easily.
Motorcycles generally have better brakes than police vehicles.
These come in handy because for every acceleration, there is an equal and sometimes more urgent deceleration. Using straight-line quickness, you can increase the distance between you and the police. Using superior braking, turning, and acceleration, you can evade the police on streets where straight-line speed is not helpful. If you have one police officer in a slow car, your chances are pretty good. A police officer in a fast car will make this whole escapade more difficult.