I am surprised that the cartridge bottom bracket on my mountain/urban bike has only lasted about 5,000 Km.
It started making clunking noises so I have replaced it with a Shimano unit.
The original is branded Neco and I believe that that they are made in Taiwan.
Perhaps this brand is a bit suspect?
As I live in a farming area, the land around here is like a billiard table, so I have not done any hill-climbing, at all.
I admit, that I cycle to keep fit and always use the highest gear possible, so that I have to work all of the time. This means that there is always quite a bit of pressure on the drive train.
Perhaps this practice has contributed to the premature failure?
I'd be very interested to hear comments.