Hub Centric Rings? What are they for?
 

I ordered 17x7 Konig unknowns for my 05 xB. they haven't come yet. I hear they come with Hub Centric Rings what are they for? do i need to use them with these wheels?

Thanks.

Yes--they came with my unknowns as well. They will basically keep the wheel on straight. I have heard of people not getting them as part of their package and having to get them later.

so what are they and how do you put them on?

Q. What are hub-centric rings; do I need them?

A. Most aftermarket wheels are manufactured with a center hole that will fit a wide range of vehicles. The hub-centric ring is used to fill any gap that may exist between this hole and the vehicle's hub, thus centering the wheel on the axle. If you have vibrations after installing new wheels, chances are hub-centric rings were not used.

http://www.discounttire.com/dtcs/infoWheelFAQ.dos

As far as installation, they just push right on. Make sure you brush away any rust the may be around the hub to ensure they seat properly.

i have a buddy with 22s on his magnum that were balanced but still had a vibration that was due to them not being lined up with the hub, once he put them on vibration went away so they do help in some cases

Does anyone know first hand if they are needed on the xB with Konig unknowns 17x7's

Why? Is there any reason to not use them?

Yes, they ARE needed.

The reason behind that is because say your hub is 56.1mm (I'm not too sure on the exact dimensions, but lets go with that), and the aftermarket wheel hub is say 76.1mm so that it can accommodate anything
from a 0mm hum all the way up to 76mm, that way a wheel company can manufacture one wheel to fit a variety of cars.

A Hub Centric rings does what the name says, CENTERS the wheel around the HUB.

basically if your hub is 56.1mm and the wheels opening is 76.1mm, you have 20mm of open space, and a Hub Centric ring will fill in that distance.

If you don't have one, expect your wheels to vibrate at high and low speeds, and your wheel bearing to wear out quickly.

To Install them, slide them into the wheel opening, the large one in the center of the four small ones.. i said that so YOU could understand what I'm saying.

i would say no but my tire package doesnt come with them and i need to know if i can mount them tommorow without them and not have trouble. also it would be nice to talk to some one that has the unknowns to get the right size of the rings.

You can mount them without hub centric rings, but you need to be very careful when tightening the lug nuts to keep the tire centered perfectly. Still not a guarantee, tho.
It's probably not going to cause major damage to your vehicle, but if the wheels are slightly off, you will get vibrations at speed.

If you look at the pic below, my wheel is sitting on the hub WITHOUT an HCR. Notice how much gap is at the bottom.

They are very simple to install...mine are plastic...they just slip over the hub and the wheel fits over them...very easy to deal with and better safe than sorry...

good information and graphics on hub rings below


http://www.prestigewheel.com/Catalog/HubRings66_67.pdf

I honestly dont understand how a rim will not be centered if the lug nut is conically shaped and so are the holes in the rim. That means(to me) that the rim will self center around lug studs as you gradually tighten them. Am i wrong?

Theoretically it should center the wheel, if done properly. But when all the weight of the wheel and tire are hanging on the studs it is making it off-centered to start with. If you carefully alternate the lugnuts as you tighten them, OK, but how do most shops do it? They hang the wheel on, slam one nut tight with the impact wrench and then the others. Odds of it not centering perfectly go up.

I don't think anyone's saying you should never drive a car without them, but if you are going to spend a lot of money on wheels and tires, I would throw an extra $20 for HCRs to help protect my investment. And If I was getting vibrations after having put on aftermarket wheels, I would try the HCRs before going through the trouble of having the tires re-balanced or the alignment checked. Why do carmakers match their wheels to the hub size? They could just rely on the conical factor too, right? It's just some piece of mind each time you have to remove a wheel.

Agree ^^^^. I normaly turn the tire as i tighten lugs (by hand first). Thats how i was shown when i worked at the auto repair shop. But spending $20 is a cheap way not to have a worry, so i agree, its worth it.

Does anybody know the exact wheel hub diameter of an xB? I have some Miata wheels with a hub dia. of 54.1 and need to know if I will need hubcentric rings.

Well, apparently the Miata and the xB have the same hub size, 54.1mm, so I can use them without fooling with hubcentric rings. Miata OE alloys are plentiful.

I know some people complain about plastic vs aluminum hubcentric rings. I just got a set today for my Enkei RPF1's from Tire Rack and they're plastic. They're a hard plastic too. If they work in conjunction with the lugs to center the wheel, why do some people think aluminum is more important? I'd worry about aluminum being softer...

I wanna say that's the same. I gotta double check.

I concur with the notion that without the Hub centric rings, the entire weight of the car is sitting on the lug stems, and not supported by the hub. This in my opinion would not be too good. My son is an auto tech for Toyota and that is also his perception-along with eliminating unnecessary vibration. When the tire wobbles, it puts undue stress on those lug stems. So, put on the HC rings.

If hubcentric rings weren't important they would not have the center hub sticking out even for the steelies. It's not as important with 5 or more lugs but with only 4 studs why risk it is my motto.