Non hub-cetric mags

[LL - NY]

Not to get into any great arguments, and certainly NOT to dismiss the
importance of hubcentric wheels (I wouldn't go any other way, why bother),
the article doesn't discuss anything but anectdotal evidence (just claims
the bolts/lugs would experience shear loading) about the importance of wheel
centering rings. Do I think that impact loads would be assisted by
hubcentric
wheels? Yes. Do I think any of the plastics used have incredible compressive
yield strengths? Perhaps, or perhaps not. At the moment, I haven't the time
to calculate the compressive loading caused by lugs, and I'd have to look up
the static (one would have to assume the wheel is NOT in motion relative to
the hub) coefficient of friction of steel vs aluminum to get some idea of
the shear strength of the friction loading between the wheel and hub, but
I'd figure on a napkin that it's pretty impressive. Anectdotally, it appears
Greg G has found that few have experienced any catastrophic failures from
not using centering rings. I wouldn't go to the track like that (you're
pressing 10/10ths there, consistently) but I think you can safely get around
town without fear that you've missed a ring or so.

LL - NY - calculations and figures to follow in the next week or so. Yes,
I'm THAT busy.


On 9/11/06, Ingo Rautenberg <i.rautenberg at waratap.com> wrote:
>
> Sorry, Lee.  I must disagree.  While it may have been true in the past,
> when
> cars where the non- high HP/ Hi Speed ones we see today and where the
> sheering forces of potholes and the like are like they are today.  The
> plastic hubcentric rings work because they are pretty darn hard and serve
> to
> evenly-distribute the forces along the hub and wheel mating surface.
>
> You might enjoy this read from Dan Barnes at Sport Compact Car:
>
> http://www.sportcompactcarweb.com/tech/0205scc_wheel_tech_guide/
>
> Best,
>
> Ingo
>
>
> ----- Original Message -----
> From: "LL - NY" <larrycleung at gmail.com>
> To: <brett at cloud9.net>
> Cc: <McCohens at aol.com>; <quattro at audifans.com>
> Sent: Sunday, September 10, 2006 4:53 PM
> Subject: Re: Non hub-cetric mags
>
>
> > Considering that most of the hub centric rings I've seen seem to
> > be made of nylon. Don't think they're carrying any (in this case)
> > compressive loads of significance. Now, what REALLY is keeping
> > the shear loads from the lugs is the compression of the wheel hub
> > against the axle hub, which supplies an impressive amount of frictional
> > force with properly torqued lugs. Hence, very little lateral (okay,
> shear)
> > loads on the lugs. And the pre-load due to to the provided torque should
> > handily deal with any unanticipated loads.
> >
> > Don't think there is much danger here. And BTW, to support Greg,
> > I've occasionally misplaced the centering rings on my former GTi's
> > non-hubcentric American Racing AR24s changing wheels at track/autoX
> > events. The cone seats did just fine for me to get home, with a fully
> > loaded car. Did fine until I got the new centering rings, too. Didn't
> > usually bother reinstalling until the next event.
> >
> > LL - NY
> >
> > On 9/10/06, Brett Dikeman <quattro at frank.mercea.net> wrote:
> > >
> > >
> > > On Sep 10, 2006, at 1:19 PM, McCohens at aol.com wrote:
> > >
> > > > Got a cheap set of wheels today, once home and on the car I noticed
> > > > they
> > > > don't have hub-centering rings.    If I pull them tight real
> > > > carefully will it
> > > > be OK or am I looking at a never ending wheel vibration  issue?
> > >
> > > Not having a centering ring subjects the lug bolts to constant
> > > shearing forces (think potholes, bumps, etc.)  So, no, it's not
> > > really safe- and you will increase the dangers of bolt failure by
> > > over-tightening them, particularly if they're old and original.
> > > Torques exist for a reason, and it's not just "so it's easy to remove
> > > next time or doesn't fall out"; it's also to prevent the fastener
> > > from being stretched or deformed (and weakened as a result.)
> > >
> > > Call the previous owner and ask him/her to go looking for them. Worst
> > > case- I lost one of the centering rings for my Ronals, and the local
> > > Direct Tire shop had 'em in stock for pretty cheap ($5-ish?  Maybe
> > > $10?)  HOWEVER, you do need to know which kind you need; in my case,
> > > they inquired about the color of the plastic and any stampings on the
> > > other 3 rings.
> > >
> > > Oh, also make sure that the lugs have the proper seat.  Most audis
> > > are ball, many aftermarket wheels are conical.  The two are NOT
> > > compatible except for emergencies, really.
> > >
> > > Brett
> > > _______________________________________________
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> > > quattro at audifans.com
> > > http://www.audifans.com/mailman/listinfo/quattro
> > > ---
> > > Watch this space for ads :)
> > >
> >
> >
>
>