All handlebars - At the options menu, select the "Cheat Codes" option, then enter "NOHANDS" as a code to unlock all handlebars. If you entered the code correctly, you will hear the sound of an engine.

All Fox gear - At the options menu, select the "Cheat Codes" option, then enter "CRAZYLIKEA" as a code to unlock all Fox gear. If you entered the code correctly, you will hear the sound of an engine.

Easy store points - Go through single player Nationals, and earn the Mils Mesas environment or enough points to purchase it. After getting this map, exit the mode that you are in, and go to single player. Choose the custom event option, then go to "Nationals". Select the Mils Mesas track. Set the play mode to "Single Play", laps to "10", and number of opponents to "0". The MX superclass vehicle is recommended, but you can use an ATV or normal MX. Start the race, and do not worry about time or anything else. Just do as many tricks as possible. Try Dingo Backflips+ and 360+ for quick points. You can get about 700,000 score points and 350,000 store points.

Moves

360: Press Left + Right + RB.
9 O'clock Indian Air: Press Up + Y.
9 O'clock Nac: Press Right + Y.

Backflip: Press Up + Down + RB.

Can Can: Press Down + Y.

Disco Can: Press Left + Y.
Double Can: Press Up + B.
Double Grab: Press Right + B.

Hart Attack: Press Down + B.
Heel Clicker: Press Left + B.

Indian Air: Press Up + RB + Y.
Ninja Nac: Press Right + RB + Y.

No Footer: Press Down + RB + Y.
No Handed Disco Can: Press Left + RB + Y.
No Hander: Press Up + Y.
Nothing: Press Up + B + RB.

Pendulum: Press Right + B + RB.

Rigomortis: Press Down + B + RB.
Rock Solid: Press Left + RB + Y + B.
Rodeo: Press Left + B + RB.
Ruler: Press Up + Y + B.

Saran Wrap: Press Right + Y + B.
Shaolin: Press Down + Y + B.
Side Saddle: Press Left/Right/Down + Y.
Sterilizer: Press Up/Right + B.
Stripper: Press Left + Y + B.
Super Can: Press Up + RB + Y + B.
Superman: Press Right + RB + Y + B.
Superman Seatgrab: Press Down + RB + Y + B.

Taunt: Press Down + B.

Accomplish the indicated achievement to get the corresponding number of Gamerscore points:

MX MINI (10 points): Win the "Fast 50s Minimoto Series" in X-Cross Tournament.
MX LITE (10 points): Win the "MotoXXX Freestyle Series" in X-Cross Tournament driving an MX LITE.
MX (10 points): Win the "Kicker Supercross Series" in X-Cross Tournament driving an MX.
ATV (10 points): Win the "FMF National Series" in X-Cross Tournament driving an ATV.
Monster Truck (10 points): Win the "M2R Opencross Series" in X-Cross Tournament.
Trophy Truck (10 points): Win the "DWT Opencross Series" in X-Cross Tournament.
Sand Rail (10 points): Win the "UNI Opencross Series" in X-Cross Tournament.
Offroad Buggy (10 points): Win the "PEP Opencross Series" in X-Cross Tournament.
ORV Sport (10 points): Win the "Oakley Opencross Series" in X-Cross Tournament.
Offroad Golf Cart (10 points): Obtain an Offroad Golf Cart as a reward in the Event Series or X-Cross Tournament.
Sprocket Collection 1 (10 points): Collect all Free Ride Sprockets in Clearwater.
Sprocket Collection 2 (10 points): Collect all Free Ride Sprockets in Crawley Creek.
Sprocket Collection 3 (10 points): Collect all Free Ride Sprockets in Del Sol.
Sprocket Collection 4 (10 points): Collect all Free Ride Sprockets in Copper Valley.
Sprocket Collection 5 (10 points): Collect all Free Ride Sprockets in Greenfield.
Sprocket Collection 6 (10 points): Collect all Free Ride Sprockets in Kittery Point.
Sprocket Collection 7 (10 points): Collect all Free Ride Sprockets in Lakewood.
Sprocket Collection 8 (10 points (Collect all Free Ride Sprockets in Pine Lakes.
Sprocket Collection 9 (10 points): Collect all Free Ride Sprockets in Split Oak.
Sprocket Collection 10 (10 points): Collect all Free Ride Sprockets in Sutherlin Valley.
Longest Jump (10 points): Successfully land a Longest Jump record of 300 ft.
Wheelie King (5 points): Successfully perform a 500 point wheelie.
Stoppie King (5 points): Successfully perform a 250 point stoppie.
Stunt Man (10 points): Successfully perform a 5x stunt combination.
Golden Boy (50 points): Win a Gold Medal in each Event Series.
Iron-man Champion (100 points): Win the X-Cross Tournament Pentathlon Trophy.
Globetrotter (25 points): Compete in all available Game locations.
Hall of Famer (50 points): Set 5 new records.
Speedworld (200 points): Achieve one of the top 5 Best Lap Record for each race course.
Shop-a-holic (100 points): Unlock or purchase all items in MX vs. ATV: Untamed.
Wreck-less (25 points): Complete one Freestyle event without wrecking.
Connected (10 points): Win 5 races on-line.
Winner's Choice (25 points): Obtain the Winner's Choice option 3 times in a row while playing on-line.
Explorer (5 points): Enter an on-line Free Ride location with at least one other player.

Additionally, there are eight secret achievements, three of which are currently unknown:

Kudos (0 points): Watch the credits from start to finish.
Clean Freak (0 points): Wash off all the mud on your vehicle and rider in a large body of water.
Daredevil (25) points): Perform a 8x stunt combo.
Holeshot (50) points): Win a total of 10 Holeshot awards in Supercross races.
Fearless (50) points): Perform a 10x stunt combo.
ATV Triple Threat (25 points): Get a Gold medal in a ATV National, Supercross, and Fresstyle event series.
MX Triple Threat (25 points): Get a Gold medal in a MX National, Supercross, and Fresstyle event series.
Hat Trick (5 points): Score three personal goals in a row within the same period in the hockey mini-game.