I don't remember the bottom bracket make/model that I have on my bike right now. I replaced the same unit a month or so ago(only 20K miles on it). The sealed bearing unit split apart on me. It was almost like the factory had press fitted the sealing unit together and the sealing unit had split apart. Their was no indication of welding or crimping anywhere. Yeah, the unit was on its way to becoming unusable. I wouldn't say they are infalliable.