How important is hub-centric?

[Nick@Apollo-Optics]

Some very quality information in this thread. I myself never knew the difference between hub-centric and lug-centric wheels nor did I know the purpose of hub-centric rings. Thanks for the info gentlemen.

 

[AZEngineer]

I bought a new Chevy Tahoe in 1995 and I put lug centric Centerline Racing Wheels on it. No crazy tire size, just the same size as our Raptors ship with. I never did get them to ride right. Here are the variables.
1) rotors are turned on a lathe. It's very easy to have the hub the wheel mounts on be perfectly concentric with the rotor and the bearing ways. If the OEM intends for the wheels to be hub centric it's easy to have no runout this way. Having all the lug bolts drilled so that they are perfectly concentric is a very different story. First turning the rotors is one machine and mounting and drilling for the lug bolts is another. Even if the desire is to do it very well, it's likely never as perfect as the hub. The tolerances necessary the the lug bolts in a hub centric design can be very sloppy.
2) wheel tolerances. Easy to make the center bore on the wheel concentric with the rim. Lots harder to make sure the lug holes are. Same reason. Lots more opportunity for error
3) balance machine. Most balance off the centerbore of the wheel. In my case they never could get the ride right this way. Then they tried a jig that mounted the wheels on the balancer off the lug bolt holes. They could never mount, balance, remove, remount, and have the wheel read as balanced.

As an engineer there just seem to be too many stacked high tolerance issues to ever have a lug centric wheel ride like a hub centric.

Lug centric is only a way for a wheel company to make and stock fewer versions. The benefit/trade off to the consumer is cheaper price and likely lower ride quality. Joe

 

[Moridin]

True, Bird. I'm sure the wheels being "cheap" in general didn't help. But as AZEngineer is saying, I've usually heard it's much more difficult to get a wheel truly and properly centered on lug-centric designs.

But who knows. If the Fuel's come with hub rings anyways, I figure it's just an insurance policy.

I am not familiar with "road force balancing," I'll do some reading on that. Is that generally available at most tire places or is it a specialty kinda thing?

 

[BIRDMAN]

True, Bird. I'm sure the wheels being "cheap" in general didn't help. But as AZEngineer is saying, I've usually heard it's much more difficult to get a wheel truly and properly centered on lug-centric designs.

But who knows. If the Fuel's come with hub rings anyways, I figure it's just an insurance policy.

I am not familiar with "road force balancing," I'll do some reading on that. Is that generally available at most tire places or is it a specialty kinda thing?

Most large tire shops should have a Road Force machine.

 

[Moridin]

Excellent. I usually have my wheel stuff done at my local Les Schwab, I'll verify they do. Thanks for the info.

 

[justvettn]

A member on this forum did start a thread about shearing his lugs off using aftermarket wheels on his Raptor, so yes it does and has happened to the Raptor. Ford let his Raptor sit for months at the dealership and would not warranty or fix his Raptor.

 

[AZEngineer]

True, Bird. I'm sure the wheels being "cheap" in general didn't help. But as AZEngineer is saying, I've usually heard it's much more difficult to get a wheel truly and properly centered on lug-centric designs.

But who knows. If the Fuel's come with hub rings anyways, I figure it's just an insurance policy.

I am not familiar with "road force balancing," I'll do some reading on that. Is that generally available at most tire places or is it a specialty kinda thing?

Road force balancing accounts for the tire not being perfectly round. Tires are not perfectly round. It can be in balance but still feel out of balance due to the out of round. Road force puts a load on the tire to help get a more real world balance. I have my tires road force balanced primarily because the process tells the installer to rotate the tire on the rim to have the out of round of the wheel and the out of round of the tire counter each other. In every experience I've had road force required dramatically less weights. Joe

 

[Moridin]

Fuel Hostage wheels arrived today, and they do have 2 sets of hub rings:





Only one was marked, and it's to reduce the size from 106mm to 78. The other one isn't marked, but it measures to a reduction to 87mm, the correct size for the Raptor.



They are a very hard plastic (inflexible), but I don't know if they're primarily for making centering the wheel easier on the hub (so the lugs then still carry the weight) or if they're designed to transfer the weight to the hubs.

My "guess" is they're mostly for ease of the wheel being centered on the hub properly as the lugs are tightened down, thus meaning the weight is still primarily lug centric.

But, I've been known to be wrong. It's a pretty hard plastic, so who knows? Maybe it does relieve the weight from the lugs and transfer it to the hub.

What I do know is that I'm not going to worry about it. Mount 'em up, and hopefully they still look as good to me on the truck as I think they do in my garage. lol

 

[Nick@Apollo-Optics]

I'm thinking that if they are actually centering the wheel on the hub then they are transferring the weight to the hubs. Perhaps billet aluminum would be better. But then what are we talking for that price-wise? I don't know.

 

[DynoDynge]

I'm thinking the solution would be to go to a local machine shop, give them the dimensions & have them carve ya out 4 rings.....Problem solved.
I did this on my Jeep, when I installed a Dana 60 in the rear & the hubs were smaller than my wheel centers. Although I made the pieces on a lathe myself, it only took an hour or so.