[fhhhstix]

Sealed bearings are not really sealed they have dust covers which do not keep out water. When we raced we used mini bearing greasers to push out the old grease and put in new. If the seal was tight against the outer and inner races to keep water out the bearing would have a lot of drag on the mating surfaces. Before you reply to this get out a bearing and hold the center and spin the out side if it spins free it can't be sealed to good. Rubber tight on metal will have some drag maybe not as much as a bushing. Don't get me wrong they use other materials to seal a bearing such as metal and fiber shield but it is not going to be a perfect seal.