When you are going to go off of a jump, use your
turbo for the tiny amount of time before you
lift off. Dont use all of your turbo when you
are moving along on the ground.
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.