NHRA Releases Results of Preliminary Investagation

[Bobby Bennett]

NHRA ANNOUNCES PRELIMINARY RESULTS OF PHOENIX WHEEL INVESTIGATION

Here's the press release

 

[.]

The left wheel then slipped slightly on the hub. The wheel studs experienced a bending force and then failure, which resulted in the wheel becoming detached from the hub.

How does the wheel "slip slightly" on the hub? If the lugs were torqued on the studs properly they shouldn't move, right?

 

[big guy]

Severe tire shake can make things go and do things they would not do under any other circumstance.

 

[jackass]

How does the wheel "slip slightly" on the hub? If the lugs were torqued on the studs properly they shouldn't move, right?

Depends on the pure force applied.... i've seen evidence of slippage on other type race cars from enough force to get the movement and they much less raw power being applied...


Billy

 

[nick name]

Hey Bobby, didya run a spell check on that title?

 

[Bullet]

How does the wheel "slip slightly" on the hub? If the lugs were torqued on the studs properly they shouldn't move, right?

I would think that even if torqued properly there would still be a certain amount of slip on the hub due to clearances between the studs and the wheel, although extremely minute.

 

[Toejam]

Wouldn't that maintain that the Beadlock failed to allow slippage such as this?? How many bolts do they use on a TF Beadlock???

 

[Chuck]

Severe tire shake can make things go and do things they would not do under any other circumstance.

I wanted to wait until some kind of report was released before commenting. You are 100% correct Paul. We have seen some of that before, haven't we? That was one of the worst cases of tire shake that I have ever seen. That amount of shake could have broken brand new studs, wheels or hubs. That just goes to show that you have to be aware of everything that is going on around you at ANY kind of motorsports event.

My condolences to the family and friends of the lady who was struck and killed.

 

[Randy]

The wheel was torqued to the hub via the lug studs and nuts. The force of the tire shake was enough to allow the wheel to slip or spin on the hub and shear the studs. That's what they are saying. Tire shake has forces you would believe.

 

[The Counterfeiter]

Wouldn't that maintain that the Beadlock failed to allow slippage such as this?? How many bolts do they use on a TF Beadlock???

I believe the beadlock system secures the tire to the wheel. I can't find any mention of tire slipping on the rim in the release.

From section 17.7 of the Rulebook:
WHEELS
Front wheels meeting SFI Spec 15.2 mandatory. Beadlock 16-inch
rear wheels meeting SFI Spec 15.3 mandatory; inner bead
minimum 14 3/4 inches (+/- 1/8-inch). Wire wheels prohibited. Rearwheel
discs or covers prohibited. Wheels must conform to
applicable tire-manufacturer requirements. Minimum diameter on
front wheels 17 inches. Any modifications and/or lightening
prohibited. Titanium wheel studs prohibited.

I don't have access to SFI specs - perhaps Randy can provide info on the current beadlock specifications.

 

[CrewGuy]

The wheel was torqued to the hub via the lug studs and nuts. The force of the tire shake was enough to allow the wheel to slip or spin on the hub and shear the studs. That's what they are saying. Tire shake has forces you would believe.

I'm not pointing my finger- I would just like to know.
How did they look at the hub and determine [what point in time] the wheel slipped? To simplify; Could the wheel not have slipped a percent in a prior run, without bending the studs?

 

[TSK]

As a precautionary measure, the type of stud involved in the Phoenix incident will no longer be in use.

What type of stud was used?

 

[Tom]

How does the wheel "slip slightly" on the hub? If the lugs were torqued on the studs properly they shouldn't move, right?

Was there another issue with having a wheel spacer between the wheel and the axle hub?

 

[Toejam]

The wheel was torqued to the hub via the lug studs and nuts. The force of the tire shake was enough to allow the wheel to slip or spin on the hub and shear the studs. That's what they are saying. Tire shake has forces you would believe.

Does that mean that adding an additional stud will eliminate that problem though?