Originally Posted by
Sluggo
I have never succeeded in cleaning out and regreasing a cartridge bearing without compromising the seals. Do you have a trick for that?
As the OP notes, these bearings are capable of handling a lot more load than they will see in bike use. However, most machinery that generates 16,000 rpm does not work in the weather and grit that a bike sees. Considering the relatively low cost, I would go with new units to insure good seals and protection from the elements. If the seals are truly intact, the grease should not even get hard with age because there is no way for the volatiles to escape.
how does one compromise the seals by cleaning? these bearings have seals only on the exposed side, they are not double-sided sealed. i cleaned them from the inner, non-seal side and didn't perturb the outer seal by trying to remove it. the balls are clearly visible from the non-seal side. i probably wasn't able to get *all* the remnants of old grease this way, but between soaking in simple green and using a soft toothbrush, probably >95% got cleaned out. i'm curious why you think the seals get compromised this way... does the degreaser dry them out? i only soaked them for about 5-10 minutes before brushing, rinsing, and drying them. visibly they appear 100% intact.
unworthy1, i agree that the term "sealed" is a misnomer in this application. any two surfaces that experience dynamic friction are incompatible with *true* sealing, but they do a "good enough" job of keeping out 99.9% of the grit that would normally get into the bearings without the seal present.