I've been getting this creaking noise, not completely synchronized with
pedaling, but clearly related.
It's a ti frame with an Ultegra BB.
I take it out, and on the casing of BB cartridge (where it faced the
bottom of the B shell) and on the inside of the BB shell is this brown
crud that looks a lot like rust. It's very, very hard and while solvent
and degreaser reduce it to a much thinner coating, it doesn't come off.
While these two parts are, I guess, technically not in contact with
each other there's not much clearance, either.
Is this actually corrosion caused by the near contact between the
titanium and the (stainless steel? aluminum?) casing of the BB
cartridge? Or is it just crud that's stuck on real good?
After cleaning everything thoroughly and reinstalling, the noise is
gone. I surmise that it was this buildup of ...stuff... between the
cartridge and the shell that was causing the noise, but there was a lot
of other grit and grime down there also, so it may have been something
else.
Thoughts?
RichC