Originally Posted by
n8tron
concerning ultegra hubs (and all shimano hubs I believe)... aren't they loose ball bearing hubs? Correct me if I'm wrong here but aren't loose bearing hubs generally not so good if you ride in the rain or damp environments that cause corrosion to the bearings as opposed to sealed bearing hubs?
no, the 'sealed' bearings can be contaminated just as easily as the cup and cone loose bearings of the shimano.
It all depends on how you want to maintain your bike.
sealed bearings, you use a C-clamp press to push out the old bearings and install new ones.
will wear out faster since there are generally fewer balls in the cartridges
sometimes requires special press to get cartridges out.
if the races get pitted, you can just replace the cartridges.
the hub still does wear out eventually if cartridges are replaced often enough.
loose ball bearings, you just replace the balls, and hopefully a regular maintenance schedule kept your races pitting free.
can use any grease you like in the bearings
easier to replace grease if it gets contaminated
lasts longer as the ball bearings are usually larger and numerous
can get pitted races, at which point the hubs are toast.
the seals on 105 and above hubs are very good. You need a pressure washer to get behind those seals.