Originally Posted by Rowan
But also don't forget bearing and race quality in your equation.
Anyway, I aim to get over all this in future by using only sealed bearings... but, I just realised... most sealed bearings used on bicycles are the generic types used in car alternators, ceiling fans and various industrial electric motors and other applications... and they *don't* use bicycle-specific grease.
Sorry, Pete, I just had to point out that little tidbit. Maybe a quick email to Shimano to find out the type of grease they use in their sealed BB and wheel bearings might put the issue to rest.
(Of course, having said that, you'll probably get a reply along the lines of "we use on our sealed bearings grease plating, a patented Shimano process that we also use in fishing reels". I doubt it, though.
)
Keep in mind that "sealed" bearings are really
cartridge bearings. Yes, they are sealed, but they are not weather-proof and their lubrication does dry up or get old.
I have re-packed cartridge bearings when that was all they needed; the seals can be pried off and then snapped back on.
FWIW, I prefer regular loose ball bearings because for the same given space they use larger (and hopefully stronger) balls since no room is taken up by cartridge components.
On the other hand, I think MAVIC's on-the-bike adjustment overcomes any complaints I might have about cartridges.