I just got my new wheels.

The place I got them from said they send all the required stuff (inc. centering rings), I just have to bolt them on the car.

I got Enkei RS+M wheels but I didn't get any centering rings.

The Enkei site claims a BORE diameter of "75".

http://www.enkei.com/RacingSeriesSpecs/RS+M.html

I see in the following thread that the RX-8 has a "67mm center bore"

https://www.rx8club.com/showthread.p...=Bore+Diameter

My math skills might be weak but last time I checked 75 does not equal 67. Am I missing something or should have I gotten centering rings?

Lastly, do the centering rings have any function other then making the install a bit easier?

Thanks!

 

Bingo - that's all they do. Once the lugs are tightened, the hubcentric rings do nothing. I got rings with my RX-8's winter alloy wheels, and never use them. I've had plenty of aftermarket wheels that were not hubcentric, and never use them. Don't worry about it!

 

You don't "need" hubcentric rings...but they make putting the wheels on easier if you are lazy when you mount them. All they do is make the wheel mate with the hub better. The tapered sockets on the wheel stud holes will center the wheels if you are carefull to tighten them carefully...ie evenly.

If you hold the wheels when you mate them up to the hub and tighten all the lugs evenly...they are just added weight

 

So what do y'all think is supporting the load of the car to the wheels?

Well..the HUB ISNT ANYMORE!!

Its not the designed job of the studs to support the vehicle load and transfer road shock to the suspension, the hub is there to do that.

No rings, no true hub support for the full weight of your car (curb weight + intertial load while cornering + shock from holes/bumps..etc).

Spend enough time around a track and you'll see what that does over time.

Yes, the rings make it easier to mount...but..if thats all they did, they'd be cheapo composite, and not machined metal guys.

 

Actually, they usually (often) ARE cheapo composite or plastic, NOT machined metal guys.

What holds the wheel to the hub? Frictional normal forces, generated by the clamping force of the lugs holding the wheel against the hub face. Period. There are NO shear forces on the lugs, and the hub centering rings do absolutely nothing towards holding the car up off the ground.

That's the honest truth - trust a mechanical engineer. The hub centering rings do absolutely nothing once the lugs are tightened.

 

Thanks guys for the help.. Been driving without the hubcentric rings for a just over a week.

I'll have pics to post soon.