I can not tell you why they fail. I can only give my anecdotal experience. Please take into account that the one racer, working on one car may have great luck with any particular part he uses of the course of his 6 race season. I will do over 25 weekends this year, averaging over 10 cars per weekend, with most cars doing double duty of some kind. It is not because I (or any other large team) are smarter than the single car owner/mechanic/driver. It simple math that I see a lot more of every failure out there.
I experimented with the white box, ebay $35 hubs. One was good for a season and 10 would be bad in a weekend. Timken was a 50% falure rate on fronts and about a 90% on rears. I have now switched to only SKF for front and rears. Yes they are expensive. But I don't have the time between sessions to be changing multiple wheel bearings every day.
Take my experience for what it is worth, and ask the engineers why the fail.
Dave
Dave Wheeler
Advanced Autosports, the nations most complete Spec Miata shop
Author, Spec Miata Constructors Guide, version 1 and 2.0
Building Championship winning cars since 1995
4 time Central Division Spec Miata Champion car builder 2012-2013-2014-2017
Back to Back June Sprints Spec Miata 1-2 finishes 2016 and 2017
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6 Time Northern Conference Champion Car Builder
2014 SCCA Majors National point Champion car builder
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2014 Central Division Champion, ITS (Wheeler)
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2007 June Sprints winner, (GT1, Mohrhauser)
Over 200 race wins and counting.
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