I believe load and weight is an issue here too,,
I do two up mostly and often lots of luggage,,,,and my left rear bearing went at about 40 000 miles;)
It started as a swiiisjjjj,,swiisssjjjj sound that grew stronger and at least i heard metal against metal sounds,,
I rode about 800 miles from sviisjjj, sviisjjj until it as totally blown ...i was on a long ride.
Now i plan to replace bearings every 25-30 000 miles and bring a set as spares on long rides.
Any workshop anywhere can reaplace the bearing( and i can help them if needed) when i am on long rides, but they probably dont have the bearings I want , so I bring them
