Roach or Pit Viper
About 60%-75% of the way through the track you will climb a steep wall and come to a checkpoint with a sign showing "No Bikes Allowed". At this checkpoint you will need to bail using
, and this will go into first person mode. Once in first person mode, you will need to navigate a series of walkways and hallways to reach the final room with a secret inside of it. The maze is quite long and there are a few places that you can go wrong, so it is best that you view the video below for reference. Once you reach the final room and unlock the challenge, the achievement should also unlock.