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Old 03-30-18, 11:01 AM
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sweeks
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Bikes: Airborne "Carpe Diem", Trek 6000, Strida 2, Dahon "Helios XL", Dahon "Mu XL", Tern "Verge S11i"

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Originally Posted by AnkleWork View Post
NASA would be one source I've read, among many others all of which indicate that ball retainers serve substantially greater purposes than convenience. What was Jobst's source (apart from his own rather expansive sense of authority)?
Citation needed (see below). I can't speak for Jobst, and can't ask him since he's dead. He's generally regarded as a credible source, though not completely without controversy.

Originally Posted by JohnDThompson View Post
FWIW, you can get 11-ball retainers to use in your bottom bracket:
I had no idea there was enough room! Hubs without cages are simple... bottom brackets a bit less so. Headsets I imagine would be a nightmare without separators... based on my experience with a BMW motorcycle many years ago!
Originally Posted by SquidPuppet View Post
Could you provide a few links to these sources? I'd like to read more about full complement bearings.
Here are two:
https://ntrs.nasa.gov/archive/nasa/c...9830018943.pdf
https://ntrs.nasa.gov/archive/nasa/c...9810009866.pdf

The first link contains the following (p. 17):
"Ball and roller bearing separators, sometimes called
cages or retainers, are bearing components that, although
never carrying load, are capable of exerting a vital
influence on the efficiency of the bearing. In a bearing
without a separator, the rolling elements contact each
other during operation and in so doing experience severe
sliding and friction. The primary function of a separator
is to maintain the proper distance between the rolling
elements and to ensure proper load distribution and
balance within the bearing. Another function of the
separator is to maintain control of the rolling elements in
such a manner as to produce the least possible friction
through sliding contact."


I stand corrected on the friction issue. Still, there must be some reason separators are not used in many bicycle applications.

The second link is for historical interest, but since it's NASA it must be good!
Steve
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