Originally Posted by
alcjphil
I have, back in the days when I was commuting up to 9000 km per year in all kinds of weather conditions
I probably have never kept a bike long enough to come close to wearing out a BB and I certainly don't ride a lot during any year. Lucky to get 3000 miles a year. I imagine many that put serious mileage on a bike do wear out BB's. However this is something that is done after 40,000 to 50,000 miles (64,000 to 80,000 km) On a bike with a decent brand BB if it wears out earlier, then IMO, there are some other mitigating circumstances that probably don't involve riding the bike.
For some that's just worrying about them when they are not showing any signs of giving an issue. Why worry about a $9 to $20 part?