Just by watching the beginning of this video, these guys are asking for trouble. This has accident written all over it.
These two dudes climb onto a merry-go-round for one dumb reason, to go around really fast. So to make this thing go even faster, these clowns use a motorcycle to up the speed. As the guys are whipping around the one guy basically can't keep it together and slams his head into the bike, ouch!