-
Hippy quoted from BBInfinite earlier:
"Bicycle frame bottom bracket shells are notoriously misaligned, inconsistent, and out of round, and so it’s inadvisable to use the bike frame as the primary aligning member for bottom bracket bearings. Yet, that’s what our multi-piece bottom bracket competition does, and this explains why their systems frequently fail prematurely and creak.
A BBInfinite OPD (One-Piece-Design) bottom bracket module is a CNC precision-machined hub---like the front wheel hub on your bike---that you press into your frame. And just like your trouble-free wheel hub, BBInfinite OPD bottom brackets have perfectly aligned bearings regardless of your frame’s BB shell alignment and tolerances. Perfectly aligned bearings are essential for thousands of miles of trouble-free use and extreme spin performance."
There's YTers like Mapdec too, who are always doing videos working on customer's luxurious road bikes that end up being faced, maybe reamed and end up with a BBI/Hambini like product due to the issues. Videos seem pretty transparent in the way they show/prove the misalignment or lack of roundness of a shell.
You can find articles from journalists on this issue too, of needing to do extra work on frames just to stop creaks, premature wear to shells, threads, bearings etc.
There's plenty out there, and there are a few brands selling 'solutions'.
Eh? A few of us have mentioned genuine cases where a one piece, press-fit BB works best and/or may solve an issue other designs exacerbate. Yeah of course, no need to buy from Hambini when there are alternative products that are designed similarly to address the same problem, but denying there's a problem with some frames seems disingenuous.