The act of docking assholes together instead of penises

Bocking is an acrobatic sport, mostly involving midair tricks, but it's really what you make of it. It's plenty fun enough to go out for a stroll, or go for a run and feel the wind in your hair, although running long distances requires extreme endurance. Daily bocking can likewise bring one's endurance to a completely new level.
As the sport stands as this is being written, bocking is more of an extreme sport than a method of transportation, although this fact may change as newer, lighter models with better springs come out.
Note: backflips and similar stunts are not made easier on bocks, contrary to common belief. They require less physical agility because of the spring action, but achieving the flipping motion is very difficult.