Originally Posted by
cpach
For reference, I'm not an engineer but I am a workinc mechanic. Sure, of course, but there are some seriously misplaced priorities when they engineer a 60g weight savings, or a half watt of drag, off a frameset and deliver frames with bb shells way out of tolerance. This has a huge impact on user experience, has real impacts on mechanical efficiency, and also is a massive time and money suck for local retailers. Also some companies have way more pf bb problems than others. This has been such a problem that threaded shells are making a comeback for road/gravel (often as T47).
This is made worse by bad ideas being common, like 30mm spindles being shoved in BB86/92 shells with impossibly thin bearings.
I get it. As a tech you're at the sharp end of customer complaints. And Hambini makes and sells bottom brackets so he's hardly a neutral observer.
But frames are not sold based on the BB shell tolerance. You say 'misplaced priorities', but what are the customer's priorities that drive the design?
Let's look at it from a different angle: Marketing is telling the engineers at Superduper Bike Company LLC that customers are demanding the lightest, most aero frames. But the engineer says, 'Nah, customer is wrong, BB spec is more important' and designs a frame that's heavier and not quite as aero, but that BB shell will never be more than +/- 5 microns off. However in the 'Road Bike Zealot' magazine frame round up the review says, "Superduper's new frame is almost .1KG heavier and in our wind tunnel tests it was 0.25s slower over 40km than the other frames ranking it at the bottom in our test." Zero mention of that wonderful BB. A blog by the popular "NYC Bike Braggart" nicknames the new frame 'The Pig' because it feels so heavy and slow. Sales nosedive. Instead of selling an expected 10,000 units, only a few hundred frames are sold. Continued development of high-end frames at Superduper is now in question and Engineering is 'invited' to explain this f*up at the next board meeting.
A lighter frame isn't a misplaced priority if it sells better. That some frames produced are bad might be the cost of hitting other metrics, and accepting the cost of some returns preferable to not hitting cost or weight targets. The unfortunate part is that some customers are certainly getting lemons which if not resolved properly to the customers satisfaction is inexcusable. Maybe it's time that the Lemon Laws are extended to bike retailers so the customer has clear recourse and drives higher industry standards.