So long as there isn't any air support: a competent motorcyclist can get away from the cops on a 1000+cc sportbike most of the time. Sure, "you can't outrun the radio" -- but with that power and a little intelligence you can be 2 towns over before the cops have a chance to coordinate, then ditch/hide the bike and change clothing.

That being said: odds are they'll still get caught. The police likely know the bike/rider, and the sort of person that runs from the cops is going to run out of luck pretty quickly with their repeated idiotic behavior.

Source: used to hang out with that crowd in my youth. They all were eventually busted, but they had successfully run from the cops multiple times.