If u want better performance, take out the bearing seal. It' better because it gives less drag but u hav to clean it more often.. But it's worth doing it.
And oil up your bearings to run smoothly. Also, when cleaning your bearings, clean ur bearings with motor spary. When doing this, place the covor under the bearing. Use the straw that come with it and blast away the dirt. Or u could fill up the little cap with motor spary, and dunp your bearings in there, give it a little shake, and wala. Clean bearings.