Welcome to the cheats for Top Gear: Hyperbike for the Nintendo 64. Below are the cheats.
All tracks
At the mode selection screen, press Up, Left, Right, L, Z, R. If you entered the code correctly, you will hear a sound.
All bikes
At the mode selection screen, press Up, Left, Right, L, Z, R, Up, Down, Down, Z, Down. If you entered the code correctly, you will hear a sound.