Enter the following codes at the Cheat Menu:
Effect: Code
Unlock Everything: LOTACRAP
All Bikes: PIKARIDE
Dennis McCoy's Stats: DMCDMAN
Max Stats for All Riders: MAXSTATS
Unlock Angus Sigmund: SIGMAN
Unlock Bird Brains: FLYAWAY'
Unlock Bobby Bones: BONEGUY
Unlock Dirt Level: MUDPUDLE
Unlock Fuzzy Yard Level: FUZYDIRT
Unlock Hotty Babe: BADGIRL
Unlock Mount Magma Level: VOLCANO
Unlock Museum District Competition: ARTCOMP
Unlock Museum District Level: ARTRIDER
Unlock Oil Refinery Level: OILSPILL
Unlock Ramp Granny: OLDLADY
Unlock Street Level: PAVEMENT
Unlock Train Depot Level: CHOOCHOO
Unlock Vert Level: GGFLYER
Andre Ellison's FMV sequence: ANDFMV
Dennis McCoy's FMV sequence: DMCFMV
Jamie Bestwick's FMV sequence: JAMFMV
Leigh Ramsdell's FMV sequence: LEIFMV
Mat Berringer's FMV sequence: MATFMV
Reuel Erikson's FMV sequence: REUFMV
Fuzzy Hall's FMV sequence: FUZFMV