Is there truly such a thing as hub centric wheel? (1 Viewer)

[teghogh]

humor me before you jump into a response. i know what a hub centric wheel is supposed to be. the OEM wheels are supposed to be hub centric. but a A perfect, zero-tolerance fit between a wheel's center bore and the vehicle's hub is practically impossible due to manufacturing tolerances in both parts. hence you are left with the follwing realistic scenarios:

1. wheel bore being slighly bigger ( +/- .0005" is the normal tolerance on machine parts) than the hub- at this point the wheel is no longer sitting on the hub and the lugs will do all the work
2. wheel bore bing slightly bigger- the wheel will interfere with the hub and will not sit on the hub
3. the wheel is press fit on the hub- they only way to achieve through hub centricity. but we know that is not a possible during wheel installation.
4. using a plastic hub ring- this option interestingly is the only way to guarantee fitment as you can press fit the wheel on to the ring with force due to plastic formation of the ring.

share your thoughts

 

[KAR120C]

I think the point is that .0005" (if that is the tolerance) will have no impact on the rotating balance of the tire/wheel. But without being hubcentric, the wheel will need a hub ring to get it back into fitment.

Without fitting on the hub, the chances of you getting the wheel correctly on the lugs without being out of fitment (and thus wobbling like mad) is remote.

 

[teghogh]

I think the point is that .0005" (if that is the tolerance) will have no impact on the rotating balance of the tire/wheel. But without being hubcentric, the wheel will need a hub ring to get it back into fitment.

Without fitting on the hub, the chances of you getting the wheel correctly on the lugs without being out of fitment (and thus wobbling like mad) is remote.

At 5 thousands gap you are no longer hub centric as the wheel doesn’t sit on the hub

 

[KAR120C]

My point is it doesn't have to sit on the hub with absolute perfection. You're getting very close and the lugs do the rest. The lugs carry the connection not the hub. The tiny amount it isn't a perfectly perfect fit doesn't matter. Not enough to make a bad fitment. F1 wheels have enough tolerance gap to slop onto on their hubs in a split second and the center lock drives it home.

To think it's not hub-centric is just being pedantic. If you correctly tighten the lugs after it's on the hub it will be a closer fit than the tire is round.

 

[YellowLab]

I've learned something new!

 

[DJ’s Sled]

Seriously appreciate the tech discussion on this.

I don’t know why - everything happened pretty fast - but my new wheels are stated as 106.1, however the installers and store manager (supposedly 30 yrs experience) said no rings were needed or would fit.
A quick measure of the mating surfaces showed both to be the same, but it was a quick demo measure without aid of a micrometer.
They demonstrated how snug the wheels fit.

If I had ordered the same wheel from Tire Rack, it would have included hub rings.
Not sure what’s going on. But I’m going to get TireRack to send me what they would have otherwise included so I can have another shop show me if indeed I need them, if they will actually fit.

Today I hit about 80, everything rides perfectly smooth. It was my first real chance with the new suspension and new wheelset combined.

I’m keeping a eye on the lug
nuts..checking to ensure tightness with my torque wrench.

Appreciate everyone’s experience and advice.

 

[teghogh]

My point is it doesn't have to sit on the hub with absolute perfection. You're getting very close and the lugs do the rest. The lugs carry the connection not the hub. The tiny amount it isn't a perfectly perfect fit doesn't matter. Not enough to make a bad fitment. F1 wheels have enough tolerance gap to slop onto on their hubs in a split second and the center lock drives it home.

To think it's not hub-centric is just being pedantic. If you correctly tighten the lugs after it's on the hub it will be a closer fit than the tire is round.

Again the only way to guarantee this in a mechanical world of tolerances is two parts being press fit. Other than that whether there is one thousands or 1 mile they are not in contact. Now you could argue that the hub lip allows for placement of the wheel more precisely so that the lugs can do the work

 

[teghogh]

Seriously appreciate the tech discussion on this.

I don’t know why - everything happened pretty fast - but my new wheels are stated as 106.1, however the installers and store manager (supposedly 30 yrs experience) said no rings were needed or would fit.
A quick measure of the mating surfaces showed both to be the same, but it was a quick demo measure without aid of a micrometer.
They demonstrated how snug the wheels fit.

If I had ordered the same wheel from Tire Rack, it would have included hub rings.
Not sure what’s going on. But I’m going to get TireRack to send me what they would have otherwise included so I can have another shop show me if indeed I need them, if they will actually fit.

Today I hit about 80, everything rides perfectly smooth. It was my first real chance with the new suspension and new wheelset combined.

I’m keeping a eye on the lug
nuts..checking to ensure tightness with my torque wrench.

Appreciate everyone’s experience and advice.

The gx hub bore is 95mm. There is no way a 106 wheel is sitting snug on 95 bore. We are talking about 10mm difference between them

 

[KAR120C]

Again the only way to guarantee this in a mechanical world of tolerances is two parts being press fit. Other than that whether there is one thousands or 1 mile they are not in contact. Now you could argue that the hub lip allows for placement of the wheel more precisely so that the lugs can do the work

Agreed, that is what I argued. Hub centric is just for initial alignment. A properly mounted wheel doesn't need to touch the hub lip or the lug bolt. The lug nut shape matches the wheel. As you you go around the wheel gently tightening the nuts, the wheel begins to properly center itself until each lug is in the center of the wheel hole and the hub lip auto-centers. Final torquing provides the clamping force that actually holds the wheel to the hub assembly. At the end of the day, the clamping force of the nut to the wheel (and wheel to hub) is what makes it work.

It's been designed to work that way since most people don't carry around a hydraulic press to ensure a true hub mechanical fit. lol

And to those following at home - that's why the recommended torque is absolutely critical to safe operation. Too much and you can damage lug/nut/wheel, etc. Too little and the nuts can work free and vibration will be the least of your worries.

 

[BoostedGX]

He’s thinking lug centric which could have some vibes if not torqued perfectly

 

[Mike'sGX]

Hub Centric is necessary for my Mercedes wheels since they use Wheel Bolts not studs.
Without using hub centric wheels it would be very difficult, if not impossible to mount the wheels.

Hub Centric is also useful for stud type mounting because it helps keep the stud threads from gaulding the inside of the wheel holes while mounting.

Proper Torque is also necessary no matter what wheels, bolts or nuts are used.
I always make wheel installers use my Torque limiter on their impact wrenches then retorque with a torque wrench when I get home.