Maybe I'll add some info in here, help clarify or solidify some understandings.

On topic #1 the load path to the hub is dependent on the hub plane vs wheel contact center. There are various ways to get to the same distance via wheel offset + spacer, but essentially when doing a load condition in CAE none of that stuff matters, its the difference in wheel diameter and offset of the planes (hub vs wheel center)

On topic #2 you all are correct to some point, the sigpot or in our world known as the pilot literally does support the vehicle's weight.
However, depending on what spec you run there is about 0.7mm gap or less, so if the wheel rotates 180 degree's this can not be true without joint slip from the wheel and hub.... and if you know anything about joints, if you get constant slip so the pilot of the wheel and hub are in full contact every rotation supporting the vehicle weight, you will get torque loss.

The primary purpose of the pilot is to align the axis rotation centers of the hub and wheel on concentric centers. This allows for a better balance for the entire assembly in terms of rotation when you actually tighten your wheel lugs/bolts.
Just like a brake disk has a pilot, so does the wheel for balance issues and judder. The pilot is typically the datum for these types of parts and used for the balance measurement and dimensioning other features of the part.
In addition the lugs/bolts also will have an alignment feature, these features work together. In addition the conical feature of a bolt/lug is also a mechanical torque loss prevention feature in shear (many people don't know that)
Secondary feature by default is to support the weight of the vehicle.

The primary purpose of the lugs and bolts is to clamp the wheel and hub joint. This joint is what supports the primary weight of the vehicle. The frictional force from the contact surface as stated.

To say the pilot does not support weight of the vehicle would be false, it will carry some amount of load, its just not the primary load path. It would have to be press fit or conical feature to guarantee contact 100% of the time.

Did I help?

 

^^^That reads right to me & thanks

For me, it boils down to: Its a system of: hub pilot / stud pilot / topped off w/some serious clamp load

 

The center bore doesn't support any weight. If it did, plastic hub rings for centering aftermarket wheels would fail in about .2 miles. Hell, the aluminum hub rings on my car are a touch loose, and you can move them with a screwdriver with the car on the ground and the wheel torqued. All of the support comes from friction between the wheel and hub mounting surfaces, which is generated by the clamp load of the fasteners.

 

^^^. The center ring supports absolutely not vehicle load. I just doesn't and cant.

 

Its likely that your ring is not sized correctly to the hub & may be off to the wheel hub bore as well

 

Maybe a few ten thousandth's. But that's how metal hub rings fit..

 

Really? Mine are tight and do not move whatsoever. I actually have to tap them out of the wheel bore with a screwdriver when swapping wheels.

 

Yup. What brand do you have? I got mine from Motorsport Tech with my spacers.

 

My motorsport tech spacers have the wheel bore centric lip machined into the spacer:



I use aluminum rings on the rear wheels and I bought them off amazon, no idea the brand.

 

Yeah, my spacers have that too. For my street wheels, I run spacers up front, and hub ring in the rear.

 

hub centric rings should be very tight