Rota Fox (17" Fuchs Replica) PCA DE Legal?

[VFR750]

Has anyone approached PCA to see if the Rota Fox (17" Fuchs) will be PCA legal for DE events.

(I searched the posts and did not see a good answer, if i missed it, i'm sorry)

The reason I ask is I had heard that the current crop of cast Fuchs replicas were not legal for DE, since the design of the hub region was based on forged Aluminum material properties.

Moses, will Rota go after TUV approval? I think if they get TUV approval, that would be enough.

[TRE Cup]

i think that if they get JIC approval (japanese market standards) then it would be fine for d/e

[Jeff Alton]

TUV approval is very expensive. Testing to TUV standards is not, but getting the certificate would cost big dollars. I am interested to know the load rating, if they are selling them for street use I am pretty sure (though not 100%) that the load rating needs to be on the actual wheel.

Cheers

[daltvater]

Looks like some testing is done, I got this from Rota today. I have no idea what any of it means. I'm hoping good things.

----------------------------

Testing.
Testing has passed, but I wasn't able to witness it and I have asked them to
do schedule one final testing of the production run for the following test.

1. CFT @ 715 kg, 100,000 cycles - cornering Fatigue test. this is a pass or
no pass test but I will document it for you guys. (photograph and possibly a
camera phone video cam).

2. 15,30,90 degree impact test. this is also a pass/no pass test. I will
have more details once I witness the actual testing.

Dan

[island911]

Originally posted by daltvater
Looks like some testing is done, I got this from Rota today. I have no idea what any of it means. I'm hoping good things.

----------------------------

Testing.
Testing has passed, but I wasn't able to witness it and I have asked them to
do schedule one final testing of the production run for the following test.

1. CFT @ 715 kg, 100,000 cycles - cornering Fatigue test. this is a pass or
no pass test but I will document it for you guys. (photograph and possibly a
camera phone video cam).

2. 15,30,90 degree impact test. this is also a pass/no pass test. I will
have more details once I witness the actual testing.

Dan

interesting... 100,000 sounds like a lot to most I suppose.

so, 100,000 cycles ... tire diameter is about 2ft . .pi ...gives about 6ft per revolution . . .x100, 000 gives 600k ft... That's 113 miles.

WOW, Rigorous.

[BlueSideUp]

Cycle doesn't necessarily mean 1 rotation. I'm not sure that they will test the wheels to 200,000 miles of use but it may not be 1 cycle = 1 rotation.

[island911]

Fatigue testing (esp of round things) is usually done in full reverse bending.

That is, wheel goes right round baby, right round, like record player, right round, round round . .. .

[DARISC]

Originally posted by island911
so, 100,000 cycles ... tire diameter is about 2ft . .pi ...gives about 6ft per revolution . . .x100, 000 gives 600k ft... That's 113 miles.

WOW, Rigorous.

Hey! So what you mean? You want your pi an' ya wanna eat your cake too?

Besides, we're not talkin' 24 hr. enduros here!

Next thing you'll be axin' if they gravity cast or pressure cast! What is WITH you?

[cashflyer]

Originally posted by VFR750
The reason I ask is I had heard that the current crop of cast Fuchs replicas were not legal for DE...

Is that something that your region imposed in addition to PCA guidelines? I had not read anything in the DE guidelines that prohibits cast wheels, or specifically the Fuch replicas. I've never been asked if my wheels are genuine Fuchs. Further, I'm sure that some of the Subie drivers run Rota wheels.

PCA-DE Standards:
http://www.pca.org/drivers_ed/standards.html

[DARISC]

Rumor has it that one of the truck's very reasonably priced gravity cast wheels broke. Damn near hit the bike!

[dfink]

I can't tell who is kidding and who is not anymore but in the picture indicated the car actually ran under the parked truck.

[RallyJon]

FWIW, a rating of 690kg is considered adequate for van/light truck wheels.

[efhughes3]

Originally posted by cashflyer
Is that something that your region imposed in addition to PCA guidelines? I had not read anything in the DE guidelines that prohibits cast wheels, or specifically the Fuch replicas. I've never been asked if my wheels are genuine Fuchs. Further, I'm sure that some of the Subie drivers run Rota wheels.

PCA-DE Standards:
http://www.pca.org/drivers_ed/standards.html

I think in light of the failures of the cast Fuch knock-offs, that many regions had this self-imposed ban. I'd think that an educated DE'er would also put a self-imposed ban. That's on the "other" cast Fuchs. I don't think the ones discussed here have much time under their belt on the street or track.

[island911]

Originally posted by RallyJon
FWIW, a rating of 690kg is considered adequate for van/light truck wheels.

So is a load rating the same as a testing load? Like a say the load rating on a light truck. My VW van has a load rating of 3/4 ton ... should it fail if I drive a 3/4 ton load over a bump? ...a bump which will significantly increasing the forces on the wheels, suspension and frame?

It kinda seems that rated load and test load should be vastly different. Maybe, say, a factor of two or three. .. for safety, at least.

[Jeff Alton]

Originally posted by island911
interesting... 100,000 sounds like a lot to most I suppose.

so, 100,000 cycles ... tire diameter is about 2ft . .pi ...gives about 6ft per revolution . . .x100, 000 gives 600k ft... That's 113 miles.

WOW, Rigorous.

100,000 in the minimum test that can be done to say "the wheel passed the test." 500,000 is what CART tests too and 1,000,000 is what F1 tests to. At least that is the info I got from a lab.

At any rate 715Kg is only about 1600lbs. Think about the corner weight you may have on one of your rear wheels. 825? maybe a little more?

Now, the info I got from a major testing lab was that the big atoumakers only test to about 1.3 times the corner weight. Race teams seem to test to about 2.1-2.4 times the corner weight.

Just some info to think about.....

Cheers

[island911]

Interesting stuff, Jeff.

On the rear wheel load. ... a car sitting there, sure, ~825. More for a corner . . more for accel, in that corner. But a wheel load hitting a bump? ...MUCH higher. Let me point out that while spring rate increases with the displacement of the bump hit, the shock (damper) goes up with speed. This means the loads go up dramatically with speed.

[DARISC]

Originally posted by Jeff Alton


Just some info to think about.....

Cheers

Given Jeff's input, I am indeed further inclined to think about and question whether it is significant or not whether the wheels are gravity or pressure cast, as well as to question the bona fides of the test lab.

Assuming (correctly or not) that manufacturers of O.E.M. wheels use only pressure casting, is it unreasonable to assume that a gravity casting, even though "beefed up" in terms of more material being used to bolster areas of highest stress, still presents a weaker and less predictable (in terms of calculating failure) product due to the casting being less dense and the increased liklihood that there will be pinholes and/or voids in the casting?

Considering that catastrophic failure of a wheel can result in loss of life, I think that it's only intelligent common sense to ask a few basic questions to satisy one's self as to whether saving a few bucks by buying a less than hi tech state-of-the-art wheel is a wise decision.

The fact that the manufacturer produced a prototype casting that is 1" greater in diameter than a Fuchs yet weighed the same as the forged original immediately made me ask, given their purported expertise and experience as a wheel maker, why would they do that if they knew that the strength wasn't there?

I personally found that questionable, and less than confidence inspiring, regardless of the need and enthusiasm for the product.

Considering that a common note amongst Porsche owners seems to be a love for the uncompromised quality of design and fabrication of the marque, I find it interesting that such questions are seemingly cavalierly set aside by some in the excitement of acquiring a wheel that looks the part, but a wheel that might have been summarily dismissed by the good Dr. Porsche were he not able to have a few very basic questions answered.

Best regards

[Jeff Alton]

This may put it into perspective......

Now, I am one of the folks who has been curious about what the load rating of these wheels would be, as tested. Just because they passed the 715Kg test, does not mean that they would not pass the 800Kg or 850Kg test etc... But, I am guessing that 715Kg is all the manufactrurer thought was required.

When testing a wheel, it is not tested to failure. Unless it fails to meet the specified load rating. So, it may be more capable than the test indicates, not I said MAY be more capable, but maybe not. Now they could have tested a second or third wheel even and found out that they would not exceed the 715Kg test, but only the manufacturer knows.

SO, Island brings up some good points. What if you are at full tilt in a turn with the left rear wheel fully loaded and bang, you hit a bump?
Well, who knows.

Another thing to consider is this....... Has anyone ever seen data saying what a factory Fuch wheel will withstand in a similar load test? IF so, please post the data and your source. I am curious to see what it will do.
I was thinking of a 16x6 as this is the size that some folks (lindsey) weld into a 17 inch barrel.

I am willing to organize the test, but am not going to foot the bill on my own. I will coordinate with the same lab that the "big three" use for testing. All I need is:

-A donor 16x6 or 7 wheel. (wheel will not be returned by the lab after testing).

- Some interested folks who are willing to share in the cost for the good of the community. I will foot 20% of the entire bill myself if required to make it happen.

I can put a seperate thread up or contact Wayne about finding the best way to do this.

I will contact the Lab tomorrow and get a price quote and let people know what it will cost. With enough folks my initial guess is about $20 per person. I can set up a new paypal account or whatever to accumulate the funds. Any one interested in finding out if all the speculation is for not??

As a side note, the last I heard, (I have not seen the data, only heard) is that a new Z06 wheel is tested to 695Kg........

Cheers

[efhughes3]

DARISC: Well stated.

Jeff: I'd be willing to contribute if we can spread it around like that.

[RallyJon]

It's a RATING, not the dynamic load capacity of the wheel nor the load at which the wheel vaporizes.