[G30M]

i have heard both sides of the argument

some say the wheel hub must be same size as axle hub, not to use hub centric rings

some say use aluminum rings not plastic

retailers says use plastic don't use aluminum, it's the bolts that hold the wheel in place with friction

can anyone comment before i make a mistake?

(used plastic ring for a workhorse subaru for 60,000miles and wheel corner has a creak for 10,000miles and dealer can't figure out what it is!)

[DanG]

My BBS wheels came with a metal centric rings. I also had BBS wheels on my previous M235i which came with metal centric rings.

[///MPhatic]

The lug/lug-bolt holds the wheel on the hub ring (in BMW's case, a slotted ring).
The hub ring holds the wheel on the car.
As long as there is NO space between the wheel hub center and the slotted ring, either by exact fitment, aluminum, or composite you'll be fine.

The issue arises when there is space between the wheel hub center bore and the car's hub center, transferring centrifugal forces to the lug bolts or studs.

Originally Posted by DanG

My BBS wheels came with a metal centric rings. I also had BBS wheels on my previous M235i which came with metal centric rings.

My Lotus came with metal hub-centric rings as well, but that's a bit old-school these days. Composite is absolutely fine.

[G30M]

Composite meaning plastic?

[tom @ eas]

Originally Posted by g21

i have heard both sides of the argument

some say the wheel hub must be same size as axle hub, not to use hub centric rings

some say use aluminum rings not plastic

retailers says use plastic don't use aluminum, it's the bolts that hold the wheel in place with friction

can anyone comment before i make a mistake?

(used plastic ring for a workhorse subaru for 60,000miles and wheel corner has a creak for 10,000miles and dealer can't figure out what it is!)

Hub Rings are for centering, the lugs do the job of keeping the wheels fastened.

Plastic, composite or aluminum is fine for street use, for those seeing a ton of track/brake use - plastic will deteriorate due to high temps.

[G30M]

Originally Posted by tom @ eas

Hub Rings are for centering, the lugs do the job of keeping the wheels fastened.

Plastic, composite or aluminum is fine for street use, for those seeing a ton of track/brake use - plastic will deteriorate due to high temps.

That suggests metal is the way to go but due to heat cycles that you are implying, maybe I'll just have to look harder for matching hub sizes and not rely on rings

[tom @ eas]

Originally Posted by g21

That suggests metal is the way to go

I'd agree.

[G30M]

due to heat cycles that you are implying, maybe I'll just have to look harder for matching hub sizes and not rely on rings as expanding and contracting might not be symmetrical and one side might end up buldging?

[HighlandPete]

Originally Posted by tom @ eas

Hub Rings are for centering, the lugs do the job of keeping the wheels fastened.

^^^^
This.

Our wheel fixings are a clamping (friction) fastener. Accuracy of initial centering prevents runout, as we torque the lug bolts. This reduces the chance of vibrations.

[G30M]

Originally Posted by HighlandPete

^^^^
This.

Our wheel fixings are a clamping (friction) fastener. Accuracy of initial centering prevents runout, as we torque the lug bolts. This reduces the chance of vibrations.

That's not my experience with my Subaru. Over time it's creaking. Re mounting and re torquing changes the creak but it's still there. Unfortunately I don't have the originals (crashed) to remount to see if it's go away. Dealer says nothing wrong with the car side of things

[HighlandPete]

Originally Posted by g21

due to heat cycles that you are implying, maybe I'll just have to look harder for matching hub sizes and not rely on rings as expanding and contracting might not be symmetrical and one side might end up buldging?

Plastic or composite rings shouldn't compromise use. Only a problem when remounting wheels, if the rings are damaged. They are not taking radial weight transfer when torqued correctly.

[HighlandPete]

Originally Posted by g21

That's not my experience with my Subaru. Over time it's creaking. Re mounting and re torquing changes the creak but it's still there. Unfortunately I don't have the originals (crashed) to remount to see if it's go away. Dealer says nothing wrong with the car side of things

If a BMW gets creaking issues there are OE friction discs which are fitted to prevent further movement.

[tom @ eas]

Originally Posted by g21

due to heat cycles that you are implying, maybe I'll just have to look harder for matching hub sizes and not rely on rings as expanding and contracting might not be symmetrical and one side might end up buldging?

IMHO, you're putting a bit too much thought into it and making it more complicated than it needs to be. Seasoned techs can even center the wheel using the lugs and without the ring in most cases, but rings should be used if the application requires it. Some aftermarket wheels are properly sized and don't require rings.

Your wheel manufacturer (assuming you're running aftermarket wheels) should be able to provide the needed rings. If not - they are easily found at most wheel shops, and even amazon/ebay. You'll need to measure the wheel centerbore and wheel hub (66.6mm on G-chassis) to get your sizes.

[HighlandPete]

Originally Posted by g21

That's not my experience with my Subaru. Over time it's creaking. Re mounting and re torquing changes the creak but it's still there. Unfortunately I don't have the originals (crashed) to remount to see if it's go away. Dealer says nothing wrong with the car side of things

BTW, are they hub-centric mounts on the Subaru? Some manufacturers use lug/nut mounted wheels.

[G30M]

Not sure sorry.

Ok I won't think too much with the BMW... Let's leave it at that

[tom @ eas]

Originally Posted by g21

Not sure sorry.

Ok I won't think too much with the BMW... Let's leave it at that

Its not a bad thing, guilty of it myself most times. But you're doing the right thing and asking questions first.

[BMWCCA1]

I've used E39 wheels on my E28s for decades. Always used aluminum rings. Never had an issue.

[rbryantaz]

I have always viewed the hub centric rings as just a way to more quickly install the wheels squarely. It is more of an install aid that isn't required if the wheel is installed carefully and properly.

One important side note that is often missed that I didn't realize for a long time:
Wheel centers being true and specific is actually more critical for tire install and balancing than putting the wheel on the car.

I realized this when I wanted to use some 7 series wheels on my e70. I considered using a router to enlarge the centers and rely on the lugs but after some research I realized there would be no way to balance the wheel if the center isn't perfect!


As for using hub centric rings in general

The center ring also prevents someone from quickly putting a wheel on with the lugs not centered and cranking them down incorrectly (by not tightening in a star pattern). If the wheel is installed carefully then there is no real advantage to them.

Where I see the rings being important is when wheels are changed quickly at the track and there isn't time to install the wheel meticulously.

IMO Rings also aren't really great for fast wheel changes either though because they can fall out, etc. I think if used for that purpose they should probably be high temp glued into the wheel.... (coat the spacer/wheel center with glue then install on the car until set) After that there is no fumbling with the ring.

For my X5 space saver on the e90 I have a plastic 74.1->72.6 ring RTVed into the wheel to make it more or less a direct fitting wheel. It isn't necessary but I had the rings laying around and it only took a minute to do. I did this before I installed the tire on the new rim and even took it to discount tire that way and they had no issues putting the tire on.

For a real racing setup where the hub gets super hot then aluminum makes sense with some higher temp glue. I have seen pictures of melted plastic rings from track days.

-Rich

[ash4252mine]

What type of hub sizes are you looking for?

[ash4252mine]

Originally Posted by g21

That suggests metal is the way to go but due to heat cycles that you are implying, maybe I'll just have to look harder for matching hub sizes and not rely on rings

What type of hub sizes are you looking for?

[shawnhayes]

Originally Posted by rbryantaz

For a real racing setup where the hub gets super hot then aluminum makes sense with some higher temp glue. I have seen pictures of melted plastic rings from track days.

-Rich

I've melted two sets of the cheap bullshit TireRack sent.

I got aluminum now, but it was a pain to find them perfect, but they're out there.

Shawn

[86Zed]

Seems the basics have been covered here. I would also suggest running plastic if you are in a winter weather road salt environment, or a decent amount of anti-seize.

Ran plastic on a track car and got a bit wonky after a season or two, at $20 a set not that much of a headache.