The rider begins the ollie by crouching and jumping directly upward. As the rider begins to leap, instead of lifting the feet from the board, he/she "pops" the tail by striking it against the ground, which raises the board nose-first. Maintaining contact with the board, the rider lifts the front leg and bends the front ankle so that the outer or top side of the shoe slides towards the nose of the board. The friction between the shoe and the board's grip tape helps to guide and pull the board upward, while the rear foot only maintains slight contact with board to help guide it. When nearing the peak of the jump, the rider lifts the rear leg and pushes the front foot forward, which levels the board and keeps it in contact with the back foot.
It's a neat piece of science art, and it also tells us something interesting. The arrows show us that the force on the skateboard is constantly changing, both in magnitude as well as in direction. Now the force of gravity obviously isn't changing, so the reason that these force arrows are shrinking and growing and tumbling around is that the skater is changing how their feet pushes and pulls against the board. By applying a variable force that changes both in strength and direction, they're steering the board.
4 amazing skateboards in one nice lot. 1. 1990's Tony Hawk Conplete Skateboard, original falcon 3 design. With Rekon trucks and firelite classic wheels. 2. Sk8mafia Lucero deck. Signed by John Lucero. Brand new deck. 3. 1031 deck signed by entire team on a brand new creepy crawl deck. 4. Brand new super rare Big Mess deck with Blast design. This deck is extremely rare and is a must have for any collector. Both the signed decks are personalized to a guy named Jason that owned a skate shop here in Grant's Pass Or. Those guys were on his wall for a long time before he went out of business. If you have any questions or concerns please let me know. Thanks for looking. Steve