You have to win 1500 points, but it doesn't tell you how many gold skate wheels you have until you have finished the game. For every extra 500 points you get after you reach 1500 points, you get another gold skate wheel. The gold skate wheels can be traded with Olivia Kickflip once per day for coins.
NOTE: Gold skate wheels do not go on any Skateboard.
NOTE: You can only get up to five gold skate wheels per game.