If just replacing the bearings doesn't get it smooth enough, and if you have the patience, try re-packing it with toothpaste instead of grease and spin it by hand for an hour or two to polish everything smooth. Then obviously clean thoroughly and repack with fresh grease and bearings before you ride it.
If just replacing the bearings doesn't get it smooth enough, and if you have the patience, try re-packing it with toothpaste instead of grease and spin it by hand for an hour or two to polish everything smooth. Then obviously clean thoroughly and repack with fresh grease and bearings before you ride it.