If you happen to fall off your bike (ie. you misland a jump,) when your character is running back to the bike, tap A as fast as you can. He will kind of shake when he is running and get to the bike faster.
Better Jumping
When you are going to go off of a jump, use your turbo for the tiny amount of time before you lift off. Don't use all of your turbo when you are moving along on the ground.
