Originally Posted by
jfowler85
My own personal experience, as well as that of two buddies, one of whom races, is completely opposite of yours (with exception, as mentioned, to powerspline) in that no problems have surfaced with either external or interal BBs. That's the problem with anecdote, the sample size is 1 and often contradicted by some other bloke's experience. Ie it's useless as an extrapolated statistic.
Explain why a cottage industry of external bottom bracket bearing replacement sprouted as soon as external bottom brackets became popular. That isn't anecdotal, that is a fact. While external bottom brackets have improved a lot, the fact remains that a low end internal BB will last 20+ years with no maintenance. I'd like to see a external BB do that.