sentences:  Worse still when not observing carefulness, a Freestyle setup can easily hook on vertical surfaces including steps, coping and funbox edges if you roll over them, leading to tripping incidents.This is why the technique to 'bash' (see "Flat Setup") a staircase is almost impossible on a Freestyle setup.Freestyle frames can be purchased, although removing the two inner wheels of a flat or anti-rocker frame technically makes it freestyle, however this would not be very durable due to the lack of solid grinding material.