i can do them, but the pavement must be an asphalt road not a gritty new one or concrete. When you do it, there's so much weight on the rear wheel that the pedals slowly overcome the skid so you can't hold it. More practical however is to skid ALMOST on the seat. I usually kinda pinch the seat and turn my back leg's knee in a tad. that way it's LOCKED. i do 48/17