Mike Jacoubowsky wrote:

Your experience is fortunately atypical; in general, even the less-expensive
Shimano BBs tend to last a great many more miles than people would think.
Bearing wear/failure/contamination has rarely been an issue with Shimano
BBs. Creaking noises, caused by the manner in which the left-side cup slides
over the rest of the bottom bracket, is another matter entirely. That's the
issue I'd like to see addressed.

Even the Shimano BB's that start with "LP"? I purchased two different
bicycles new that came with stock LP-27 BB's, and the bearings in
neither lasted over 2000 miles. Their UN-52 replacements are doing fine,
however.

--
Tom Sherman - Earth