On Sun, 29 Apr 2018 17:34:00 +0100, Roger Mills
wrote:

On 29/04/2018 10:18, T i m wrote:


So, are you saying that in fact any wheel on any (conventionally
wheeled) car wouldn't need to rely on hub-concentricity, once the
fasteners were tightened correctly ... if the spigot ring could be
removed after the wheel was fitted?


Yes - provided that the wheels and nuts have conical mating faces.

Check.

It
might be a different story if the wheels and nuts had flat faces (were
any ever made like that?).

I think many ally wheels are like that Roger and hence rely 100% on
hub-concentricity to give accurate alignment and (potentially)
'support'.

I'm aware that wheels can stick on the spigot rings, and take a
seemingly lot of (human) force to remove.

Repeatedly hammering the rim outwards from the inside with a 2lb club
hammer and after the application of a release agent, yes. ;-)

But I don't think you'd get
far if you started driving round with the wheel nuts removed.

No, but the fact that you could drive *at all* suggests that the fit
between wheel and hub was far more than 'trivial'?

I think the nut type does help define the expectation / system.

A conical / rounded wheel-nut face and mating dished_wheel_socket
means that the wheel could be 'stud centric' and may or may not also
have an interference fit at the hub (and if it does it's likely to be
more tolerant to high shock loads like hitting the kerb etc).

A flat faced nut / stud is very likely to be hub-centric as there
would be no other way to ensure the wheel was mounted concentrically.

If you ever bolt two things together where the mating faces are
basically flat and the bolt holes offer reasonable clearance, I would
say you could make one move compared with the other (holding one in
the vice and hitting the other with a hammer at 90 degrees to the
joint) more easily than you could pull one away from the other?


It will be interesting to hear what the trailer manufacturer says
(assuming they say anything).

Cheers, T i m