I have a set of these with the 77/177 hubs, great set of wheels... however the bearings in the freehub need replaced again! I replaced them in May, now I have done probably a few thousand miles on them. My mechanic tell me there is no seal on them so the water and grit can get in very easy. Is this normal for a set of these wheels, the summer weather was pretty good so not much water or grit could have penetrated them. Any advise or other peoples' experiences would be greatly appreciated!!