Stoppie Master Achievement in MX vs. ATV Supercross Encore
Pull a stoppie over 25 feet
How to unlock Stoppie Master
Again, head to the Touch The Sky track found under Rhythm Racing and move around to the left where the ramps are. Accelerate straight ahead and gain some speed with a clear line of sight, so not to hit anything. Lean forward with and apply the front break with and the bike should 'nose wheelie'. Do this for 25 feet and the achievement should unlock.