I ride MTB, and just made adjustments to my rear derailleur and it skips a gear from 6 to 8. that said, I hit top speed and tried a little off road and hit a hole in the ground. My face hurts and it was awesome, now how do I properly set this bitch up? I use Shimano trigger shift and components. it's a Mongoose dual suspension POS, but it's great for my area.