Originally Posted by
RoadGuy
That's funny. The Dura-Ace 7700 bottom bracket is advertised and sold as a sealed cartridge bottom bracket. Meaning it's designed to not need to be overhauled until replacement. Doesn't mean that it can't be taken apart, only that it shouldn't need to be taken apart and serviced during it's service life. Anything can be taken apart with determination, the problem usually comes when trying to reassemble.
....
The inner protective sleeve may say "sealed," and it does have
seals, but it still needs to be maintained,...as per Shimano's instructions. As I understand, it's essentially an adjustable cup & cone BB with needle and ball bearings and needs periodic cleaning and greasing.