BB30 Bearings/Lifespan? Not Good IME!

[Sterba]

Thank heavens those of us who ride steel frame can still get cartridge bearings fitted with JIS square taper axles. Once fitted, you can forget all about them, whatever the weather. There's a lot of codswallop out there about greater stiffness of the new large bearings, but if they don't last, it doesn't matter how stiff they are. Now I've seen the above I am all the more convinced that today's bikes prove their durability at the customer's expense.

 

[andrew_s]

Still on square taper here. You can't get much better than Ultegra and Dura Ace square taper cartridge units. Only been fitted 18 plus years.

The only trouble is that the high end Shimano BB cartridges are no more. I just had to replace a10 year old Ultegra (UN72) after it developed a bit of play after too many floods. UN54 is as good as it goes now, though still good for 20,000 miles or more. Good is still available though - the SKF taper BB comes with a 10 year warranty (which was 100,000 km the last time I looked).

 

[RecordAceFromNew]

The only trouble is that the high end Shimano BB cartridges are no more. I just had to replace a10 year old Ultegra (UN72) after it developed a bit of play after too many floods. UN54 is as good as it goes now, though still good for 20,000 miles or more. Good is still available though - the SKF taper BB comes with a 10 year warranty (which was 100,000 km the last time I looked).

Indeed. I have been buying UN7x bb's for spares whenever sellers are not asking for silly money. But that is mainly because they are lighter (because they have hollow spindles). The UN5x also seem to last very well because they are also well sealed and have large (and according to this interesting assessment outwardly seemingly the same) bearings.