wmf62

Bill

wmf62

FWIW, the 'load' is not carried entirely by the studs but is shared by the frictional resistance of the proper torque value tighten/clamping of the rim to the drum/rotor surface and the 'shear' of the stud.


Bill

TCracingCA

Mentioned above was the lug style and that type of seating does away with the need for this! Also if you have the spongy tall side wall tires it really doesn't matter! If you have gone to a low profile radial tire then you don't want rotational inconsistencies, which would result in a bounce skip vibration or oscillation! Some of the quality rims did center on the bearing area and or the mag lugs were more precision fitting!

jim lockwood

A single 7/16 UNF grade 5 bolt, torqued dry to 55 ft-lbs will produce a clamp force of about 7500 lbs. With 5 such bolts retaining a wheel, I'd wager there is zero shear applied to the wheel studs and 100% of the load is applied as frictional contact between the clamped surfaces.

dcamick

My C1 aftermarket TTO American Racing wheels have a hub bore of 82.56 mm. My wheel hub OD is 71.30 mm.

I was recently told that without the centric rings (synthetic or aluminum) that gap would create a vibration and put undue stress on the lugs.

I purchased synthetic rings to take up that 11.26 mm difference.

emccomas

I just installed the Volvo S40 aluminum wheels on my Suzuki Forenza. I got aluminum centric hub rings to install in the Volvo aluminum wheels.

They fit nice, with just a light couple of taps to get them in the wheels.

And the centered the wheels very nicely.

Definitely the way to go, at least for this application.

DUB

Unless I was having a total brain fart...for all these years....I can say the countless factory wheels (aluminum and ralley's) I have serviced always went onto the hub and held.

And you could only rotate the wheel so the wheel stud rocked back in forth in the hole for the lug nut. And...the wheel did not have to be lifted in order for the lug nut to seat in the taper. This also includes 1984 to 1996 wheels also.

SO...the factory wheels are NOT like the old school Cragar S/S wheels where you had to get the wheel on right to get the lugs to work.

Granted...I did not ever take out a feeler gauge to see what the gap measured at like Jim has shown. But knowing that is has to be quite minor of a gap...because when I lift up on the wheel I can not feel any up and down play.

And I know the wheel can not be a 'press fit'. At least knowing the wheel does not have a huge hub opening....just seems to make sense to me.

Funny thing....across the parking lot I share......they do tires and wheels...and the wheel balancer he uses balances the wheel and tire using the center hub hole. And one day the owner's brother needed to get new wheels balanced for his truck and he could not do it due to he needed to use a balancer that uses the lug holes for centering...and not the center hub hole. When he tried to balance them...the wheel was so jacked up that you could visibly see that it was not spinning true.

So...

DUB

wmf62

if there is ANY gap at all, short of an interference fit, it is not hubcentric

Bill

SJW

Agreed.

Most of the vehicles I've wrenched on through the decades have had a very close fit of the wheel to the hub. Not quite an interference fit, but the hub provides very nearly perfect centering before the lug nuts are installed. In fact, I wore myself out breaking a steel front wheel loose from the front hub on my '94 C-1500 a couple of years ago, as it had rusted solid to the hub. Road salt is so nasty.

The Hunter Road Force vibration control system I use has optional adapter plates for wheels that can't be centered by way of the hub hole, but nearly all of the passenger car wheels I've ever seen would center up just fine on the machine by way of the hub hole for balancing purposes. If you need to balance a wheel that won't hub-center, find a shop that has a set of adapter plates. It can be done. You don't have to abandon the wheels.

I'll add that the bubble balancer I used for years when I was a gas station mechanic back in the '70s and '80s centered the wheels via the hub hole, and I never had one come-back because of a balance problem. I probably balanced over 1,000 wheels that way.

Strictly speaking, I'd classify nearly all of the passenger car and light truck wheels I've seen as lug-centric, as it's the tapered lug interfaces that positively locate and secure the wheel to the hub. But, on most of them, the hub hole is centered well enough, is close-fitting enough, and is round enough, to provide sufficient centering for wheel balancing. Notable (and rather obvious) exceptions would include the eight-lug wheels that were used on some '60s Pontiacs, and the early Volkswagen wheels.

Live well,

SJW

wmf62

Bill

ejboyd5

Here is a good example of a hub-centric wheel:

DUB

Hub-centric or lug-centric. I guess when it boils down to it I have been wrong. Who knew that a few thousandths of an inch made that much of a difference. I guess if I can slide a .0015" feeler gauge between them...then it is not an interference fit (obviously)..so it has to be lug-centric.

But..I can say...that I much rather install a wheel where the center of the wheel fits very well on the hub....so the lug studs are centered in the tapered holes ( if it is that design of wheel).

So regardless if it has a gap of .0015" or a 1/4" still makes it a lug-centric wheel..(I got that)...but I prefer NOT buying into the reproduced Ralley wheels with the center hole being HUGE...and the companies who sell them say that they are better and improved....or something to that effect I just do not agree with it. I just do not like installing wheel that can hang on the lug studs when being installed....but that is just me.

DUB

dcamick

Please explain how a hub Centric ring would work on the rear wheels of a C1 1961.

There is no Rear hub to center on. With my American Racing TTO wheels the ring would never contact, in any way, the rear axle hub.

However, the rings work fine on the front wheel hubs.

SJW

Unless your wheels have an interference fit to a hub, they're lug centric anyway, so don't sweat it. It's the conical interface between the lug nuts and the wheels that positively locates the wheel. You'll be okay.

Live well,

SJW

TCKT B8

In addition to my Corvettes, I also have a 350 SBC powered '87 Pontiac Fiero that I put C4 brakes on. I had centric rings made so the C4 rotors would center on the Fiero hubs.

SJW

I'll wager that little car is more fun than a barrel full of monkeys! How challenging is it to shoehorn the SBC into one of those little go-karts?

Live well,

SJW

DUB

That has to be one rip-roaring experience.

When there is a will...there is a way.

DUB

OldCarBum

Through my search to purchase new wheels for my '73, I've talked with several wheel manufacturers regarding this issue of hub-centric versus lug-centric wheels.
They basically all told me the same thing.
Most aftermarket and OEM wheels are designed as lug-centric. They are safe and there should never be any issues as long as the wheels are properly installed and torqued to the proper value. One manufacturer, Vintage Wheels, told me that they produce lug-centric wheels for corvettes and other performance vehicles every day. They said they set extremely tight tolerances on the dimensions between the wheel center and the location of the lug holes to insure the lugs center the wheel when torqued and all aluminum lug-centric wheels should have steel reinforced inserts installed in the lug holes. They also told me that they include the lug nuts to insure the proper mating surfaces are maintained between the lug nut and wheel. They did recommend hub-centric wheels if I was planning to race my Corvette and said they would manufacture me a set for a slight additional charge. Vintage Wheels also manufactures PIN drive wheels.

Punchy8504

So what would the recommendation be for my scenario?

I just picked up this '77 and here is what came with the car. The holes are slotted, there were inserts in some of them which seemed more like washers and as you can see I don't have all of the proper lug nuts.

I like these rims, but I will need to requisition proper nuts and inserts to get them to fit. The pictures aren't the best quality/lighting/angle but the first thing that came to mind were hub centric rings. The studs are barely long enough to poke through the rim but the proper nuts rectify that.

However with the hole in the rim being slotted it seems to me that there can be a lot of room for error and the rings would solve that. I plan on taking the car to my trusted tire guy and see what I can do but I'm just trying to see if I'm on the right path first by looking into getting the rings and the proper nuts and inserts.

Punchy8504

And to note, I had to put the wheels on when picking it up and the rims wouldn't fit onto the hub so we had to knock the inserts out. It seemed weird as the rims came off but wouldn't go back on.