Long story short, the oldest specification BB30 shell can be adapted to any current diameter and length crank spindle. Successful avoidance of BB creaking appears to depend upon either the use of full shell width adapter, the two sides of which are tightened into the shell by threading them together, AND/OR the use of a Loctite resin to cement the parts into the shell.
The situation with PF30 is similar except that PF30 BBs with metal sleeves, broad contact surfaces and captured bearings appear to give the most reliable assemblies with regard to avoiding creaking. Nevertheless a more common PF30 BB with a narrow plastic cup holding the bearings can often be completely successful if properly installed with Loctite.
BB30 and PF30 BB shells offer the highest likelihood of the available designs for the greatest compatibility with any future crank specification.
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Robert
No matter where I go, here I am...
Last edited by rpenmanparker; 11-13-15 at 07:49 PM.