This trick is possibl in two locations; Portland or Staunton Island. First, enable the "Have The people follow you" code and enable the mods of not falling off the bike and moon jump faster enabled. Also have unlimited health or body armor. In Portland in Chinatown (travel north from the bridge and look to the left), you will find a moped that begins the "Noodle Punk" side mission. In Staunton Island, go to the west side of Phil Cassidy's to find the "Joe's Pizza" mission, which is similar to the "Noodle Punk" mission. When you have everything ready, get on the moped and go to a large clear open area. Have someone on your bike with you. Press Triangle and Up together repeatedly to exit the mission and get on the bike. If done correctly, the bike should tilt to the left in a weird way. Hold Analog-pad Up and hold Square as if doing a stoppie to make the moped start to spin rapidly, as if it were a helicopter, and fly off into the air. Note: If your vehicle does not have unlimited health it will catch fire and explode.