Super speed:
This trick requires a Microsoft Sidewinder 3D Pro controller. Set the throttle to control the acceleration. Then, while playing any event or mode, move the throttle to around 3/4 Full and watch your speed. It will rapidly increase and go over 100. Be careful, as your turning speed is decreased the faster you race.

Extra stunt points:
Repeatedly press [Print Screen] when jumping for extra points.

Extra boost
Press [Tab] when riding up a hill.

Big head mode:
Enter big heads at the main menu.

Jeremy McGrath's bike
Enter kcussedocuroy at the main menu.

New Honda bike:
Enter HONDAISACE as a name.

Big Air:
In a Supercross race (practice), go off the track and ride as fast as possible. Hit a tabletop from its side and lean back. This will make you jump extremely high.

New trick:
Do a jump big enough for a trick, then hold [Space]. Your rider will do a different trick, but you will not get any points.

Good camera view:
Press the [Left Shift] + [Down] when you are in the air doing a stunt or jumping.