On 2004-12-13, Lanny Chambers > wrote:
> In article >,
> Grant Edwards > wrote:
>
>> Since they're supposed to bear most of the weight of the car,
>> I would think that one would want metal ones.
>
> They don't bear any weight at all.

If so, there's a _lot_ of misinformation being spread by people
(including wheel manufacturers and car mags). According to
Ronal USA's web site:

"A hubcentric fitment, is one where the interior of the
backside of the wheel - referred to as "centerbore"-is an
exact fit to the "hub"-that protrudes from the mounting
surface of the wheel. The relevant issue here is that the
WEIGHT BEARING of the wheel on the car is done on the HUB
when it is "mated" to the wheel! This has to be an exact
fit. The LUG NUTS, simply affix the wheel and hold the
wheel to the car and do not affect load bearing."

According to Sport Compact Car magazine:

"Hubcentric wheels have a hole at their center that fits
closely over a round feature on the hub, serving to center
the wheel on the axis of the spindle, as well as bear the
vertical weight of the vehicle. The wheel bolts or studs
then serve simply to hold the wheel onto the hub, and are
loaded only in tension, where they are strong. If the studs
were required to absorb vertical forces, they would be
loaded in single shear, the weakest arrangement for any
fastener."

> All they do is help center the wheel until you can get the
> lugnuts on, and plastic works fine for this trivial task. The
> lugs carry 100% of the weight.

I think you're quite probably correct, but there sure is a lot
of misinformation out there...

> You can leave the hubcentric rings out with no ill effect.
> Just observe the normal lug tightening sequence: run them all
> up finger tight, then torque them in two steps, in a diagonal
> pattern.

A set of rings is only 10-15 USD, and it seems like good
insurance.

--
Grant Edwards grante Yow! I'm CONTROLLED by
at the CIA!! EVERYONE is
visi.com controlled by the CIA!!