High quality sealed bearings have more (but smaller) "balls" inside but look the same on the outside. They are stronger and smoother because the load is spread around the bearing races more, but can cost up to 2 or 3 times as much. A mate of mine with connections with bearing suppliers has this habit of changing rear suspension pivot bearings immediately from new into high quality ones. I don't bother because I don't ride that hard for it to make any difference in my case.

A lot of "stock" regular sealed bearings have very little grease inside and is quite runny at that. Water getting in or bearings running dry are the main reasons for sealed bearing eventually failing. I know a race bike mechanic who knows how to pop the seals without damaging them and he re-packs new sealed bearings with "real" grease swearing it would out-last the bike... according to his experience.

I seldom had the need to maintain rear suspension pivots. Forks on the other hand are a different story. Might pay to check the fork manual... lubing the bushing cavities and stanchion seals on some forks need to be done more frequently than we realize (as little as several hours of accumulative running time). Same goes for rear air shock units. Most stanchion seals scrub only one way... so a thin film of oil is allowed out but not back in. Allowing these seals to run "bone" dry is a sure fire way to wreck them and can result in damaging the rear shock or fork unit before their use-by date.

Slightly wet dust ring marks made by dust seals around fork stanchions (or rear shock units) is a good sign. I would consider dry (or overly soppy wet) dust ring marks as a warning sign.



.