Allow Lightened wheels?

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FatSebastian
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Re: Allow Lightened wheels?

Post by FatSebastian » Wed May 19, 2010 10:26 am

Duane wrote:It seems to me that a wheel's weight can be accurately measured at check-in, without removing it from the car.
Like this or this?



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FatSebastian
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Re: Allow Lightened wheels?

Post by FatSebastian » Wed May 19, 2010 10:43 am

pwrd by tungsten wrote:
Stan Pope wrote:I approached it by specifying which surfaces could be "worked" and geometry limitations on that work, using original wheel features as reference but no "precision measurements".
I like that aproach.
I do too. Stan, can you post the rule language that was used, or point to a URL that already contains it? :eager:



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Duane
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Re: Allow Lightened wheels?

Post by Duane » Wed May 19, 2010 11:01 am

FatSebastian wrote:
Duane wrote:It seems to me that a wheel's weight can be accurately measured at check-in, without removing it from the car.
Like this or this?
Yes, thanks!

No test fixture is needed, if the mounted wheel has plenty of sideways slop. But cars with treated or commercial wheels may also have tight tolerances sideways on the axle. I think this method could also be done with the car and wheel in a normal attitude. Lift the car (or lower the scale) just enough that the axle nail lifts off from the bottom of the wheel hub. The builder can't eliminate that intra-hub slop.

At check-in or at post-race re-inspection, if some wheel weighs less than (say) 95% of the lightest of some measured population of stock wheels, the car then gets closer inspection after the races.



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Re: Allow Lightened wheels?

Post by gpraceman » Wed May 19, 2010 11:14 am

The problem that I see with weighing wheels is the time it would take to do so at check-in. To be fair, I would think that you would have to weigh at least one rear wheel and one front wheel. One might argue that you really need to weigh all of the wheels touching the track.

Personally, I think it would be better to do a visual comparison with an unworked wheel. If there is any question, then get out the calipers and compare that measurement with the limit specified in the rules.


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Stan Pope
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Re: Allow Lightened wheels?

Post by Stan Pope » Wed May 19, 2010 12:05 pm

pwrd by tungsten wrote:That is a trick. It is almost impossible to write a good rule. Thoughts apreciated.

Some key factors are the writting on the outside and inside of the wheel must show. But that allows some store bought semi-lightened wheels to exist...
Here is where we ended up for 2010:
Wheel Treatment: Wheel treatment (material removal, smoothing and
polishing) may only affect the wheel bore, hub faces, outside tread surface and
tread edges that might rub the guide rails. Wheel tread surface must be cyndrylical and no narrower than the original wheel. BSA is phasing in a new wheel design that is distinguishable by the movement of injection marks from the tread surface to the
inner face of the wheel. On old design wheels, some of the original “tread marks”
on the wheel face must be intact. On new design wheels, the entire original
“tread marks” must be intact.


In so far as I could tell, only the least invasive of the purchased finished wheels qualified.

When we are sure that pre-2009 wheels are out of the pipeline, the distinction between "old" and "new" will be removed. We may revert to the old tread mark limitations, as it is difficult to do much to the new wheels without cutting off a bit of tread mark somewhere around the periphery.


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Re: Allow Lightened wheels?

Post by bbrownrigg » Wed Apr 09, 2014 2:50 pm

Seems that with a mandrel, a Dremel or drill, and a steady hand, anyone could achieve lighter wheels without high cost or technology? Am i over-simplifying this?

I agree with the notion that anything requiring "high tech" or "high touch" changes the playing field. Keeping it fair is a good thing, but pushing the envelope -- slowly -- is also a good thing. Like moving from graphite to oil/dry lube.



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Re: Allow Lightened wheels?

Post by TXDerbyDad » Thu Apr 10, 2014 1:06 am

bbrownrigg wrote:Seems that with a mandrel, a Dremel or drill, and a steady hand, anyone could achieve lighter wheels without high cost or technology? Am i over-simplifying this?

I agree with the notion that anything requiring "high tech" or "high touch" changes the playing field. Keeping it fair is a good thing, but pushing the envelope -- slowly -- is also a good thing. Like moving from graphite to oil/dry lube.
You may well do more harm than good. While light is good, concentricity is better. Both are ideal, but it would be impossible to get both without a lathe.



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