I have a used one, I don't know where these ball bearings are supposed to go. It keeps making a popping noise, it that normal. I don' have anything in between the base and the post. I have placed little felt pads on the post. Is that where the BB go? I don't have any BB, I have just seen them for sale as parts for this thing. Thanks for any replies and pictures that you great BYCer's are great for!