My turn FWIW:
Dave added some to this topic, clarifying it for himself and hopefully
others. Indeed the looser the nut is the more aggressive (faster) the
tightening is.
There are also other good reasons for the taper on the nut and wheel
hub: Centralizing the wheel has also been pointed out. Additionally
a taper increases the surface area of the contact and therefor
increases the friction between the two parts. If you've ever used
Morse tapers on lathe tools, or pounded in the mouthpiece of a trumpet
you know how tight two tapered surfaces can get.
Barney's roll of tape is the nut and the socket is the splined hub.
Forget about the wheel's actions. AS the socket is smaller in
diameter than the roll of tape it must turn more revolutions to travel
the same distance as the insideof the tape roll. Conversely the roll
of tape turns fewer revolutions than the socket for a given distance
and is therefor spinning ever so slightly slower (Less RPMs).
Spin a left side wheel counter clockwise and grab the nut to make it
go slower than the hub. What happens? The nut tightens as it has RH
threads. Spin the wheel on the right side clockwise and grab the nut
to make it go slower than the hub. Because it has LH threads, it
tightens.
Going back to Barney's roll of tape and socket, the forces causing the
tightening of the night occur irregardless of braking as long as the
vehicle is going forward. Braking may want to loosen the nut because
of the nuts inertia, but the tightening action is still ocurring as
the hub rotates forward and counteracts to some extent the inertial
force acting on the nut.
One other observation. Note how the ears of the Knock 0n are shaped.
The UNDO's face is made so you can get a better whack on it to
loosen. The opposite more angled face used for tightening doesn't
need that much whacking as it will tighten up by itself.
I hope I haven't offended anyone. :-)
Blake
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