Hubcentric doesn't mean hub-supported. It just means 'centered using the hub'. That's why the plastic hubcentric inserts on my aftermarket rims aren't snapped into pieces every time I take them off!

no offense, but im a little surprised a track guy like yourself do not know about wheel structure... :ugh2:

aftermarket wheels are usually lug-centric by design so does not rely on the hub for support. people are using the hub and centering rings to aid in aligning their wheel correctly when they torque down the lugs. this is why lug-centric wheels use lugs that have a taper.

on the other hand, our stock sport wheels are hub-centric. that means it relies heavily on the hub. the lug is used to keep the wheel attached to the hub. this is why there is no taper on the lugs... more just a flat washer.

Agree to disagree. I think you're confusing centering and support. They're different beasts and lug- or hub-centric is just about how the wheel centers when mounted. Neither suggests where the forces are applied once correctly installed.

When you correctly install and torque a wheel, the flush inner wheel face and outer hub face make for a contact patch that distributes the car's weight. The friction between the hub/spacer face and the inner wheel face is where the load is being taken. The wheel neither sits on the studs nor the hub/spacer lips.

This is a topic discussed ad-nauseum on other forums.

FWIW, my Z's factory lugnuts are tapered...

you got part of it correct but still not understanding the difference between these two wheel structures and where the loads are placed.

also your factory lug nuts have tapered tip because you are using standard lug-centric lugs readily available in the OEM market which have dual function.

some cars (toyota for instance and other nissans probably) use hubcentric wheels and regular steelie donuts. donut wheels are like a hybrid of both hubcentric and lug-centric design. they have universal lug bores so that they are compatible with both tapered and acorn nuts. (honda for example use acorn nuts on some of their cars). their center bore matches the hub diameter intended for the car to give it that hub-centric stability. basically steelies need to be cheap and universal.

so in summary, your stock universal hub-centric lugs have dual function yet you are only using one of the 2 functions. :)

i donno spearfish, do you feel comfortable running those spacers on the track? :confused:

im not sure if i'd be. i've used the eibach 20mm's on street with no issue but that's quite different from track application...

Sure. I've run them at Road America and now the full course at Autobahn with no problems at all. They're the stud replacement type so I'm much more comfortable with them than if they were the bolt-on type.

One of my rear tires did pick up a giant self-tapping screw which has me pissed off today.

Yah, at the end of the day you're the pilot and captain of your ride so if you feel comfortable you're fine.

Sorry to hear about the screw. Ive had my share of flats too... and curbed wheel the other week which I bought a new replacement wheel and tire. :D

Another broken H&R spacer victim here... I installed them a little over a month ago, 2 autoX events and 1 trackday later and 2 of the 4 rings are broken of. All 4 are 15mm. No more spacers for me. Anyone interested in 2 as good as new spacers or 2 no longer hub-centric spacers? :rolleyes:

Yeah, it's just the 15mm ones that are the problem. I guess they can have the 2 of mine that are still good, combined with yours they can have a full set!

Looks like we need an additional section on the site: Group sale :icon17:

On a more serious note, why would it only be the 15mm ones that break? I'd assume the design and machining of the hub-centric ring is the same for both. Only difference is the thickness of the actual spacer, isn't it?

The 15mm units have a thin point in the wall where it has to curve in to clear the stock hub ring. This curve generates a very thin point in the spacer ring where the aluminum wall thickness is < 1mm thick. The thicker spacers don't have this clearance issue and hence have a full thickness hub ring.

Take a close look at your spacer and the piece that broke off, try to piece it back together and you'll see what I'm talking about.

Yep, I saw that curve and was wondering why it was there. If that curve would not have been machined out there would not have been that thin wall thickness issue. Interesting, I didn't know that the 20mm spacers do not have that curve shape there.

im sure keeping an eye on mine........

My replacement ones are still good. I had the wheels off this past week, and they looked fine.

I looked at JB's broken spacers today too. A couple conclusions I've come to:

1) there is no way in hell the car's weight is supported by the spacer lip. If that was the case, the lip would break off the moment you lower the car off the jack. As Chris noted, the spacer lip thickness where it attaches to the main spacer body is as thin as a soda can's wall. That simply cannot support a car's corner weight and supports what I said about the lip merely centering the spacer.

2) Something is happening during wheel mounting or dismounting that is breaking these. Either a struggle with the wheel leads to knocking off the lip, or perhaps the lugs are being tightened down without the wheel completely seated on the spacer. That would potentially pinch off the lip when you tighten one lug with a poorly seated wheel. Finally, I'll never ever loosen my lugs without the wheel being up in the air. That will most definitely snap the lip off.

3) I may get a set of 15mm Ichibas and just keep them in the garage. That way I can slide them on if an HR breaks while still using the same extended HR studs.