wheel weight determination and policing

[MHISSTC]

My opinion differs slightly with regard to what is currently accepted as, but which is currently not clearly written into, the rule regarding the overall weight of the wheel.

 

I agree with the previously determined CMC forum interpretation of the wheel weight being the weight of the bare wheel without the balancing weights, valve stem, track schmutz, and tire, and not the "as raced" interpretation we had at the 2013 Nationals. However, after much discussion over the past several years surrounding the topic of including/excluding the weight of the wheel spacer in the wheel weight with that spacer either somehow being attached to the wheel or loose from the wheel, I disagree with the interpretation that the wheel weight should include the weight of the spacer attached to the wheel because that is a variable that can be adjusted by the racer and isn't something that should be taken into consideration when shopping for wheels and comparing the manufacturer specified wheel weights.

 

In order to fairly police wheel weight, I feel we need to do it one of two ways.

 

1. If we continue to specify just the wheel weight in the CMC rules it needs to be the bare wheel weight with absolutely nothing attached to the wheel by the racer. That also excludes the weight of any spacer that would not be attached to the wheel as it comes from the wheel manufacturer. This is a little bit harder to police if the racer can not provide manufacturer documentation on wheel weights because everything has to be dismounted and remounted and some manufacturers don't state wheel weights in their literature.

 

2. If racers prefer to go with an "as raced" interpretation and configuration, then the entire wheel/tire/balancing weights/spacer (including any non-attached spacer)/valve stem combo needs to be weighed in it's entirety. I think this would actually be a much easier way to check it since there would be no tire dismounting, wheel weight or valve stem removal and replacement required! All we need to do is come up with a new target weight for the "as raced" combination. It's pretty easy to pull all 4 off the car, so we may need to specify if only one will suffice to serve as an example for the entire car, or if we need to weigh all 4 to be certain.

 

Using Enkei's own documentation, lets look at the Enkei RPF1 wheel in a 17" x 9.5" 18mm offset size.

 

The manufacturer states in their literature that this wheel weighs 16.75 lbs. In my view, this is not a legal wheel. If I look at the 38mm offset wheel, it's 16.25 lbs. At this point, I'm not going to think to myself, "Gosh, if I attach the spacer that I need to use this wheel and push it out to maximize track width, and if that spacer just happens to also weigh 1.75 lbs, I'll have a perfectly legal wheel." Instead, I'm going to move on to another model with the same manufacturer, or go to another manufacturer to find a wheel that weighs at least 18 lbs as shipped from the manufacturer. Is this the grey area we talk about? Is this how we separate those who are truly serious about winning from those who just want to play and build a legal car?

 

[HMark]

I agree that the spacer should not be included in the weight. Every chassis must run wheel spacers to be competitive, so the weight needs to be permanently attached to the rim in any area except as a spacer on the mounting flange. That is how Derek has his wheels in Calif. I think that is a proper interpretation.

 

How were Aarons wheel spacers attached? Bolts? Glue? If they were not welded, I would not call them permanent.

 

-Don

[MHISSTC]

I agree that the spacer should not be included in the weight. Every chassis must run wheel spacers to be competitive, so the weight needs to be permanently attached to the rim in any area except as a spacer on the mounting flange. That is how Derek has his wheels in Calif. I think that is a proper interpretation.

 

How were Aarons wheel spacers attached? Bolts? Glue? If they were not welded, I would not call them permanent.

 

-Don

 

So the spacer should not be included in the wheel weight, but it should be if it's permanently attached to the wheel? I disagree with that and I vehemently disagree with welding anything to the wheels. Do you realize what you are implying when you are allowing folks to modify wheels?

 

Not taking into consideration the liability factor and to make a highly exaggerated point, it would then be totally legal for me to get a freakishly light set of 10 lb magically reinforced forged unobtanium wheels in a totally wrong offset, and then be allowed to make a large custom spacer out of the same unobtanium to bring it up to a total of 11 lbs, then I could also drill out portions of that spacer and add enough Mallory metal slugs to the hub area to bring the wheel weight up to the required 18.0 lbs. And if I weld that spacer to the back side of the wheel so you can't see the Mallory slugs, you have no idea they are in there. Viola! I just made some super cheaty wheels that are totally legal but have only a fraction of the rotational inertia as a set of off-the-shelf wheels with no spacers that actually weigh 18lbs on their own. They are the same weight and are technically legal, but with my super cheaty wheels I can now accelerate faster and brake quicker because the mass is concentrated at the hub.

 

How am I supposed to shop for wheels based on the wheel weight requirement then? Do I look for one just under the 18lbs and then count on making it up in spacer weight, and only if I also weld it to the wheel?

 

I don't agree that every chassis has to run spacers to be competitive. If you really wanted to open up your wallet, you could call up any number of custom wheel manufacturers and have them custom make you a set in whatever offset you needed, and exactly as light as you specify. I don't have those kinds of funds.

 

Is any of that worth it to the average CMC racer? Or does the average CMC racer do like I do and follow the intent of the rule by looking for wheels that are actually 18+ lbs as listed on wheel manufacturer web sites or by emailing or calling their customer support when those numbers aren't available in their literature?

[D Algozine]

What is the difference if a spacer is welded or is loose on the studs ?

If its included in the legal weight minimum, it's just an opportunity to manipulate the rotating mass, and skirt the whole point of the rule. Which I assume is to eliminate the purchase of light weight and expensive wheels. Including the spacer nullifies the intent.

 

Personally, I think it should be 18lbs , no spacers, as delivered from the manufacturer. Otherwise it is an area to get creative and expensive if your motivated. And as we have learned from some of the most minor change requests, CMC is not about expensive or creative.

[CMC#11]

Just my point of view:

 

-custom wheels are perfectly legal.

-if you buy a wheel (Enkei RPF01 as the example), and them permanently attach a wheel spacer, then you are making it a custom wheel.

How is that different that if Enkei took the RPF01 and ran a special production for CMC racers and put it to 18.01 lbs? The only difference is the racer is doing it vs the manufacturer doing it.

 

I also don't see a way to have a min weight for the entire wheel, valve, spacer, tire combo. The difference in tread depth will change the weight of the combo greatly. Each 1/32nd of tread weighs about 1 lb.

[Glenn]

I will only accept a wheel as legal if the spacer needed to help it make weight is welded on to the wheel. There is no way for CMC to police the placement of where the weight is in the wheel w/out requiring a SPEC wheel. That is not w/in the spirit of CMC.

 

Dave A - The gains one can get from weight placement w/in the wheel are very small compaired to the advantage total weight can give. While you are technically correct, there is a gain, it is small. We will never be able to remove every advantage, but we can work towards making then as small as possible.

[37Stang]

Why not do away with the weight requirement of the wheels and just put a "dollar limit" on wheels such as what is done with brakes and struts/shocks?

 

For example, "wheels must be readily available to the public for a cost not to exceed $200 per wheel".

 

This would do away with custom "one off" wheels that meet the 18lb rule...

 

I am, however, not familiar with the wheels available for the GM crowd so there would have to be some consideration to keep the availability relatively equal between the Fords and GMs...

 

Just a suggestion...

[D Algozine]

I'm surprised by what I'm reading, and I'm dumbfounded by the inconsistently in the statements made about this wheel rule compared to nearly every other rule that has been debated on this site in resent months.

 

What is the intent of the rule? I assume (and perhaps wrongly) that it is to eliminate spending big dollars on light weight wheels. Can we all agree, that's the whole point of the rule or am I missing something ????

I am also going to assume ( I know never assume) that custom wheels is NOT the intent of the rule. So how does buying a $1,200 set of wheels and welding a spacer fall within the spirit of the rule, or even within the language of the rules?

Where in the rules does it say that a spacer has anything to do with the wheel weight and that by welding it to the wheel it is considered part of the wheel ?

"If ain't in rules, you can't do it"

 

7.31 Wheels/Tires

7.31.1 Wheels may be of any construction or material and must be 16 or 17 inch diameter.

7.31.2 16 inch wheels must weigh 16lbs or more. 17 inch wheels must weigh 18lbs or more. Wheels may not be wider than 9.5 inches.

7.31.3 Maximum tire size is 275/40R17 for all cars. The only tire allowed is the Toyo Proxes RA1.

7.31.4 Wheel spacers are allowed and wheels may have any offset.

 

So if you follow the rules, you buy a 17" wheel that weighs more then 18lbs, and install a wheel spacer, you are likely to end up with a wheel that weighs 20-23lbs (as nearly all CMC racers have done).

So yes 2-5 lbs per wheel is a huge difference and even having the majority of the weight in the center (wheel spacer) is an advantage, not unlike being .02 hp over the limit.............No it is exactly like being .02 hp over, which can and will get you DQ'd.

 

I don't think a dollar limit is the answer. Its to difficult to track and enforce. The rule as it is written with a few minor clarifications will get the job done nicely.

"wheels weights are measured, as delivered from the manufacturer. spacers, stems, balance weights or any other additions are not included in the measurement. 16.0 inch wheels must weigh 16.0 lbs or more. 17.0 inch wheels must weigh 18.0 lbs or more. Wheels may not be wider than 9.5 inches "

As pointed out to me, (Bob Denton is a sharp guy) you need to add the decimal point, per the tolerance section of the rules. Otherwise the measurement gets rounded to the nearest whole number.

[ls168camaro]

I have said this before but will say it again. The rules should be so that you don't have to follow this forum to know what is going on-PERIOD.

 

No where in the rules does it say that the weight is with the spacer.

[CMC#11]

If the spacer is PERMANENTLY attached to the wheel, then it is no longer a spacer. A spacer can be removed to adjust track width but once permanently attached, it can not be removed. This wheel has become a custom product.

 

Like I said earlier, this is no different than if Enkei did it from the beginning.

[Glenn]

If the spacer is PERMANENTLY attached to the wheel, then it is no longer a spacer. A spacer can be removed to adjust track width but once permanently attached, it can not be removed. This wheel has become a custom product.

 

Like I said earlier, this is no different than if Enkei did it from the beginning.

 

Michael is correct here. Listen to him. Smart guy he is.

[BADVENM]

How many Mustangs in CMC are running the wheel in question? Seems like most of us are running some type of MB wheel? Why? Maybe because they are the only or just about the only wheel to meet the 18 pound threshold and not super expensive. If I search for wheels and and see a manufacturer weight below 18 pounds I move on and look somewhere else.

 

Seems that if this wheel without all the add-ons were legal more of us Mustang guys would be using it.

 

Please let us keep this simple and just consider the weight of the wheel the wheel only and nothing else...no spacers, no weights, no valve stems, etc. Too many variables that make things just that more complicated.

[Den341548534727]

BryanL is right. You should not have to go to the forum to find out if some thing is legal or not. It should be in the rule book and the rule book should stand alone. The rule book should be a repository for all the lessons learned.

[Glenn]

One thing I will tell you is manufacture weights are not always correct. So we would have to put the wheels on a scale anyways. Once on the scale, why does it matter how the wheel hits the 18 or more pound mark? If we just used published numbers then someone would shave the backside of a otherwise legal wheel. Since we are not using scales in the world you guys propose I see more folks cheeting. Whe scale is the "go/no go" method. If it passes that I don't see what the issue is.

Now it is known what it takes to make Arrons wheels legal. He spent the cash and figured it out. He could have easily been stuck with a set of modified wheels that is not legal. Now others can copy what he has done and not face the same risk he did.

 

Things don't always work out. A lot of areas I have played in with regards to the rules has not panned out. I have a pile of useless parts on a shelf. I didn't get any of that stuff for free and nobody gave me free labor.

No risk, no reward.

[MHISSTC]

Michael and Glenn, I have always disagreed with the basic premise that a wheel spacer can be transformed into a wheel merely by attaching it to the wheel, and the spacer is therefore included as part of the wheel weight, but if I have the same exact setup without the spacer attached to the wheel, it's not included in the wheel weight. They both bolt to the hub as added weight in the same location, so why not? Anyway, I digress from my intended response.

 

The only way you can begin to convince me that a wheel spacer can be transformed into a wheel is if that wheel spacer is incorporated so well into that wheel, that it becomes a single seamless unit... ...done in a similar way as the professional shops that narrow, widen, and repair wheels that includes a full and seamless welding, machining, and finishing to produce a seamless product. Do we have CMC racers doing this?

 

As such, if we continue to specify a minimum wheel weight in the CMC rules, I will continue to disagree with considering any add-on piece in a total wheel weight that modifies the wheel or it's weight as it came from the manufacturer. If we allow modifications to standard manufacture's wheels, it makes it harder to wheel shop, we have to assume that every competitor has a potentially modified wheel, and at some point we have to go through the process of weighing every single wheel (bare) on every single car to verify compliance. Ideally, we would also have to place some kind of marking on the wheel or in the vehicle log book to also indicate the weights of specified wheels. Just because a wheel looks like a wheel we all assume to be legal (or illegal), we can no longer make that assumption.

 

However, if we are not allowed to modify wheels, then I know that every 17x9.5 Konig Torch wheel with an +18mm offset and 5x4.5" bolt pattern weighs 22.1 lbs, because I have a statement from the manufacturer saying so, and anyone can ask the manufacturer and get the same answer. MB Battles with the same dimensions come in at something like 22.4 lbs. The inaccuracies in manufacturer literature usually shows up because they only weigh one example of a particular design, or a particular design in that size. There are differences in weights due to bolt patterns and offsets that aren't normally accounted for. Some of the wheel weights shown on websites are also the shipping weights and not the actual weights of the wheels.

 

I say if we continue to specify a minimum wheel weight and we continue to allow custom wheels, and someone wants to spend $2500+ on a set of CCW wheels in custom offsets, centers, weights, blah, blah, blah, let them do it with the understanding that at any time they may be required to prove those wheels are compliant. On the other hand, if I have a non-modified set of Konig Torch wheels that is commonly known to weigh 22.1 lbs, there is no reason I ever have to take those wheels off my car, or pare those wheels down to their bare state for anyone to weigh them and check their compliance.

 

As I stated before, maybe a better alternative is to come up with a minimum weight for the removable rotating mass assembly that includes the wheel, tire, valve stem, wheel weights, and spacers. Don't tell me we can't do this because it's too hard to come up with a weight. The 18 lbs was a total SWAG to begin with because it was a few pounds lighter than several known OEM wheel weights. We already know the target weight of the minimum wheel weight. How hard is it to add the weight of a totally worn out 275 width RA1 and rubber valve stem to that?

 

I am also TOTALLY on-board with the following idea:

You should not have to go to the forum to find out if some thing is legal or not. It should be in the rule book and the rule book should stand alone. The rule book should be a repository for all the lessons learned.

 

I also think what Aaron did with the wheels was NOT in the spirit of CMC, very clever and technically legal which was an awesome move, but definitely more in the spirit of SM and not CMC. ...kind of reminds me of when we thought of using a Group 4B battery to add weight to the car... ...totally legal as the rules are written, but when we actually took the time to ask about it in advance of doing it, we were very clearly told it was not in the spirit of CMC, a generally bad idea, and the result of us doing so would be the rules rewritten to clearly disallow it in the future. Sounds to me like the opposite was done... ...find a clever way to make an illegal part legal... ...then wait and see if fellow competitors or tech folks notice, and if so, let the rules police play catch-up after the fact.

[Glenn]

Michael and Glenn, I have always disagreed with the basic premise that a wheel spacer can be transformed into a wheel merely by attaching it to the wheel, and the spacer is therefore included as part of the wheel weight, but if I have the same exact setup without the spacer attached to the wheel, it's not included in the wheel weight. They both bolt to the hub as added weight in the same location, so why not? Anyway, I digress from my intended response.

 

This part desreves its own answer.

 

Back story time. Once upon a time I was called out for running wheel spacers (1/2"). It didn't say in the rules that they could be used. But what was in the rules was wheel offset was open as long as the tires did not extend beyond the OEM fender (that rule is now changed to a measurment). So since we could run any offset, why not allow spacers to be added to cheap wheels (I had $50 in 13 OEM wheels - 16x8's) instead of having custom made wheels to max wheel offset w/in the rules of the time. The Directors of the time agreed and spacers were made legal. Now, most everyone runs them for teack width reasons as well as adjusting balance front to rear. They are a great tuning tool. Thus guys will add/remove them durring a race weekend. Thus the need to have the weled on if they count towards the wheels weight.

Now on topic....

Lets say that we allow the unattached spacer to be counted in the wheels weight. Who is going to keep the list of who's wheels are legal w/ what amount of spacer? I'm not going to do it. I'm sure none of us are willing to do it. I would almost become unpoliceable due to the logistics of it. In addition there are more than one manufacture of spacers so 1 spacer @ .25" think could be completely different from anothers .25" think one. Now, I gotta know who has how much and are they steel, aluminum, solid, single or multiple lug patterns, or do they have un-needed material removed. Not worth the hassle. It seemed pretty clear what the answer needed to be. A simple way to have the same wheel in different offsets from a manufacture perspective is to have a varying thickness at the mounting pad. This is no different that adding the needed material to the wheel. Thus offset changes as well as the weight of the wheel.

So if Arron was able to have that wheel custom made in his desired offset, he would likely spend alot more money and still have a legal wheel. Why not allow the wheel to be modified to fit his needs and become legal? I don't see a downside. From a rules enforcement perspective, it is easier if I grab a wheel and slap it on the scale and give it a pass of fail rather than asking, ..."is this legal w/ or w/out a spacer?" "Where are your spacers?" "Oh, you forgot to put them back on?" "DQ for you."

If the spacer is welded on, them I'm good w/ it. It keeps it simple for guys like me who are Directors, want to race, and what to have a good time rather than spending all night in Impound or at Tech and working Protest forms all night.

 

This also works in the opposite direction. Wheels can be milled (very liitle) to remove material and change the offset. This will also make them lighter. So an OEM wheel that is 16.0lbs (16") can be milled and become illegal. But what if we used a published spec to decide legality? We wouldn't catch it would we? So using anything other than the scale is a bad idea.

[Glenn]

The 18 lbs was a total SWAG to begin with because it was a few pounds lighter than several known OEM wheel weights.

 

Not really. 18lbs was 1lb under the OEM 2000-2002 Camaro SS 17x9 wheel. We wanted a little wiggle room from the 19lbs we knew that wheel was. We also wanted to allow a small window for non-OEM wheels should they become available. We figured at the big money wheels would be around 14-16lbs. We wanted to keep those out. We also knew the OEM wheels have a massive overbuild requirement and any quality wheel manufacture could make a similar wheel for a fair cost a little lighter than the OEM's. Some folks see wheels as a safety item. I know guys who will not track a car on OEM wheels. We didn't want to play that game.

So it wasn't a SWAG in the sence of picking numbers at random.

[Glenn]

I am also TOTALLY on-board with the following idea:

You should not have to go to the forum to find out if some thing is legal or not. It should be in the rule book and the rule book should stand alone. The rule book should be a repository for all the lessons learned.

 

That is always the goal of the Directors is to have the rulebook stand on its own two feet. If I was able to predict every exploitation of the rules I would not be a CMC Director, but working w/ the NASCAR guys.

 

We update the rulebook constantly in an effor to keep up w/ you guys.

You should have been around back in 2005 w/ that rulebook.....

[Glenn]

I also think what Aaron did with the wheels was NOT in the spirit of CMC, very clever and technically legal which was an awesome move, but definitely more in the spirit of SM and not CMC. .

 

Wrong. This very issue was talked about at length a few years ago. It is legal and was inteded to be so.

[MHISSTC]

Thanks for the back story Glenn. Where we are now makes more sense with the story of how we got here. I may still not like it, but I understand it.

 

Since we are allowed to use the spacers as a tuning device and the rest of the rules regarding track width, offset, and fender clearance have become what they are now, wouldn't it be even simpler to take the rules to the next level of progression and leave spacers entirely out of the wheel weight equation by leaving them loose and the wheels un-modified in order to "grab a wheel and slap it on the scale and give it a pass of fail rather than asking, ..."is this legal w/ or w/out a spacer?" "

[Glenn]

kind of reminds me of when we thought of using a Group 4B battery to add weight to the car... ...totally legal as the rules are written, but when we actually took the time to ask about it in advance of doing it, we were very clearly told it was not in the spirit of CMC, a generally bad idea, and the result of us doing so would be the rules rewritten to clearly disallow it in the future.

 

I don't recall it happening that way. As far back as I can recall (2004 rules) the OEM group size battery has always been required. I don't think a Fox ever had a group size battery that was 145lbs.

[Glenn]

Thanks for the back story Glenn. Where we are now makes more sense with the story of how we got here. I may still not like it, but I understand it.

 

Since we are allowed to use the spacers as a tuning device and the rest of the rules regarding track width, offset, and fender clearance have become what they are now, wouldn't it be even simpler to take the rules to the next level of progression and leave spacers entirely out of the wheel weight equation by leaving them loose and the wheels un-modified in order to "grab a wheel and slap it on the scale and give it a pass of fail rather than asking, ..."is this legal w/ or w/out a spacer?" "

 

I don't have to ask now. If the spacer is not part of the wheel (welded) it does not count towards the weight of the wheel. It is either part of the wheel or it isn't. It counts towards the weight or it doesn't. The wheel is legal or it isn't. All decided by the number on the scale.

[Glenn]

Guys, I'm late for class already. Gotta go for a couple hours.

[MHISSTC]

So it wasn't a SWAG in the sence of picking numbers at random.

 

The "S" stands for "Scientific", which indicates I know there was some basis for the numbers and it wasn't a completely random "WAG". But it still wasn't based on a set of hard numbers, only target ranges from OEM wheels that weren't the maximum size allowed.

[MHISSTC]

kind of reminds me of when we thought of using a Group 4B battery to add weight to the car... ...totally legal as the rules are written, but when we actually took the time to ask about it in advance of doing it, we were very clearly told it was not in the spirit of CMC, a generally bad idea, and the result of us doing so would be the rules rewritten to clearly disallow it in the future.

 

I don't recall it happening that way. As far back as I can recall (2004 rules) the OEM group size battery has always been required. I don't think a Fox ever had a group size battery that was 145lbs.

 

7.9.7 The battery may be relocated. The battery must be of the same type, group size (i.e. 24F), and voltage as originally equipped, or heavier, and may not be modified.

 

Notice the "or heavier" wording? I believe the way the rule is written, the use of a battery smaller than the OEM group size is specifically excluded which prevents racers from using high dollar super small dry cell batteries that wouldn't be in the spirit of CMC. But no one ever considered that someone would actually choose to use a battery that was 3x the weight of the OEM battery and the rule still hasn't been specifically written to exclude it. Is anyone keeping track of what all the OEM battery sizes are in order to know if someone is using a smaller and lighter battery than the OEM? All the cars in the series didn't come with a Group 24F battery. I think this is one of those eyeball tech items. If you have a big-ass battery, or a wee little tiny one, someone is going to call you out on it. But if you have a battery that looks "reasonable", then no one is actually going to check to see if your specific car came with that specific group size as OEM. I believe this is one of those gray areas that Kent was talking about that is both super simple, yet impossible to properly tech without being specifically quantified. I could probably get away with running a group 27 or 42 and no one would think twice, even though neither is the OEM group for my car and one is lighter while the other is heavier.