by the way the magnets r in there for a reason
for example lets say that one of your bearings starts going bad and part of that bearing gets caught by the magnet that is its job but assume u do not have the magnet in there and that piece gets in the ring gear it will either chew it up or lock the rear wheel. now if a bearing gets in the ring gear i guarantee u will come to a screeching halt
i suppose that if u found a piece of something on the magnet u would know to park it.