How well are these truck tires balanced at the factory?

pjd · September 15, 2019

Hi all. New to the forum. Purchased 2019 Colorado wt with some extras. Crew cab., one week ago.

from 40+ to about 60 mph, tires seem to bounce. like a small vibration but definitely up and down.

Took it to the dealer service dept. they said tires ballanced..ride it till 500miles and if still doing it bring it back.

500 + miles...and..yep, going back in the shop. The write up is to check the suspension but I do suspect the tires.

Thomcat · September 15, 2019

16 hours ago, pjd said:

Hi all. New to the forum. Purchased 2019 Colorado wt with some extras. Crew cab., one week ago.

from 40+ to about 60 mph, tires seem to bounce. like a small vibration but definitely up and down.

Took it to the dealer service dept. they said tires ballanced..ride it till 500miles and if still doing it bring it back.

500 + miles...and..yep, going back in the shop. The write up is to check the suspension but I do suspect the tires.

.02 First determine if the dealer has road force balance equipment..if not take it somewhere they do........most already have the Hunter equipment to address previous gen vibrators some did, some didn't, with some in the driveshaft....static or dynamic balancing of tires alone may not be sufficient, especially on low profile tires on large wheels. Tire may have runout, but even if perfectly round could have an imbalance within belts in the sidewall. Corrected my 60-65 mph vibrations and drastically reduced rear wheel hop.

Other than the shocks which should still be in spec., exactly what do they propose to change in the suspension????

Grumpy Bear · September 15, 2019

On 9/13/2019 at 5:32 PM, Wheelguy said:

Sure, I get it and I didn’t intend to imply that all repair is unsafe either. Some rim related straightening that in comparison may not be any worse than the worst tire, OK. But for me, anything more than something like that, say from a severe pothole or impact (hard curb hit, wreck) I wouldn’t do it even for free

For me, it’s not so much a matter of visible cracks, it’s a matter of whether the metal has gone past its elasticity & into the plastic region in regards to its yield. Nothing other than a tensile test will measure that & that also directly correlates (in part) to fatigue life. Each time the metal moves, it’s being rearranged at a microscopic level. Granted, I’m sort of splitting hairs with a slightly bent wheel but I’m also considering a wheel I wouldn’t & I’m almost certain you wouldn’t repair but the average Joe - welllllll.......I’d say he probably would and without being resourceful enough to consider penetrant inspection as you did.

Let me put it to you this way. The wheel company for which I worked didn’t repair anything other than cosmetic defects or by recutting the design face (called refacing) such that critical dimensions didn’t exceed print tolerances. By saying that, I’m talking about having a department, equipment & staffing to make those repairs. If a wheel was dropped from knee high, it was scrapped & melted. For me, that spoke volumes as to where to draw the line - and I saw many 2 & 3 high pallets (72 to 108 wheels total) dropped when forklifts were moving them around & turned a bit too fast with forks raised at full height. Good lord the clanging sound still resonates in my mind LOL. An event where everyone in the manufacturing area would turn to see who was driving. Each & every wheel wasn’t even inspected, just straight to the melt department.

That’s all a personal preference - not saying you’re right or wrong or for that instance & situation it wasn’t wise to seek repair. Just stating my reasons for being much more skeptical or cautious. It’s also common that when a wheel has been damaged or deformed, many things can/could and do happen - cracks, hoop strength lost, spokes bent, lessening yield strength & not each & every one of those things are repairable or measurable (unless you destroy the wheel - tensile test). Those repairs can only be done so many times before cracks do become visible & we’re not even taking into consideration heat application which makes the (at least aluminum) more brittle. However, it would more than likely take more than a single repair for heat to become a major factor.

More later regarding your original response regarding RFB, of which we’ve gotten a bit side tracked.

EDITED - SEE BOLD ABOVE

Well thought out prose and made me take a step back and thinks. So I did some investigation. I certainly have no wish to be riding around on bad rims. Forget the women children and pets....I ride in that thing!!! :crackup:

https://www.awrswheelrepair.com/safe-repairs

Checked with my shop and these are the guys he used for the repairs. ALL of your/my concerns should be laid to rest. Every wheel is tested before repair, then reheat treated and tested again. If it doesn't pass at any stage it is scrapped.

Safety out of the way, any wheel that doesn't run true can be made so and now we are back to the initial issue of band-aiding defective tires. I will stand pat. A tire that requires a road force balance is defective and unsafe.

You also got me thinking about the economics of it all. It came to me while eating a hamburger. The answer isn't in a companies ability to force feed you a defective burger. It's in yours not to accept it. You might not win your individual case but when a company gets a reputation for a bad thing, bad things happen to that company. I.E. People by their burger elsewhere. Not all tire companies make junk. Reputable manufactures will have little trouble resolving your issues. It's the discount house middle man and low volume discount manufactures that have the most issues.

I had a Mikey D Big Mac yesterday. Haven't had one in decades. Certainly isn't the burger it was when I watched Mickey open it's first store in Cedar Rapids Iowa. I will never EVER eat one again. I can go to the local tavern and buy a very good burger and fixings for the same money and get it quicker too. (is there anything slower than Mickey D's drive trough?)

Point is, that burger will live forever. It has a following. Just not mine and because it is still here doesn't make it my only choice.

pjd · September 15, 2019

24 minutes ago, Thomcat said:

Other than the shocks which should still be in spec., exactly what do they propose to change in the suspension????

All it said on the appointment was check suspension. I shall write down all the things about tires and present it to them when I go for the appointment which is this Wednesday, the 18th.

Wheelguy · September 15, 2019

5 hours ago, Grumpy Bear said:

Well thought out prose and made me take a step back and thinks. So I did some investigation. I certainly have no wish to be riding around on bad rims. Forget the women children and pets....I ride in that thing!!!

https://www.awrswheelrepair.com/safe-repairs

Checked with my shop and these are the guys he used for the repairs. ALL of your/my concerns should be laid to rest. Every wheel is tested before repair, then reheat treated and tested again. If it doesn't pass at any stage it is scrapped.

Safety out of the way, any wheel that doesn't run true can be made so and now we are back to the initial issue of band-aiding defective tires. I will stand pat. A tire that requires a road force balance is defective and unsafe.

You also got me thinking about the economics of it all. It came to me while eating a hamburger. The answer isn't in a companies ability to force feed you a defective burger. It's in yours not to accept it. You might not win your individual case but when a company gets a reputation for a bad thing, bad things happen to that company. I.E. People by their burger elsewhere. Not all tire companies make junk. Reputable manufactures will have little trouble resolving your issues. It's the discount house middle man and low volume discount manufactures that have the most issues.

I had a Mikey D Big Mac yesterday. Haven't had one in decades. Certainly isn't the burger it was when I watched Mickey open it's first store in Cedar Rapids Iowa. I will never EVER eat one again. I can go to the local tavern and buy a very good burger and fixings for the same money and get it quicker too. (is there anything slower than Mickey D's drive trough?)

Point is, that burger will live forever. It has a following. Just not mine and because it is still here doesn't make it my only choice.

More than likely, you're riding around on safe rims - but that really would depend on the repair and the location that was repaired & the extent of the original damage. My main point isn't really aimed at your particular case - but in general wheel repair of any kind without regard for severity or what's being done to repair it.

So I follow that link you posted & read the top...it states they inspect, not test, prior to repair. Why does it matter? A test implies to me they put it on a machine and performed some sort of fatigue test (not called fatigue inspection) or important validation. Inspect could be something as simple as a visual inspection. So I am happy to see they are at least looking at the wheel that's intended to be repaired but certainly not doing any tests of real value (proving the repair doesn't fail). This inspection part really doesn't matter much - splitting hairs again, but just showing you that the claim is pretty much what a customer would hope is just common sense on their part.

So move on down that page & watch their video. Starts out by stating more than 80% of repairs involve "road rash to the flange, scratching of the spoke or clearcoat degradation" or in other words things that are cosmetic defects and are a far cry from being structural defects - two different things & very important to note. Then they go on to demonstrate how well they can cosmetically repair a wheel by setting up an experiment deemed "more severe than AWRS would attempt to repair" and go on to cut a 2mm deep groove through the design face side. So they're telling ME they wouldn't touch any wheel with 2mm or MORE of any damage. OK so why do they have before/after pics showing deformations that to me are obviously exceeding more than 2mm? Hmmmm - so then why are these being repaired then (Click Photos at the top then click on Wheel Straightening to the left of the images):

For now, ignore the arrows in the center of the wheel & focus on the one in left image, the upper left center portion - that's the deformed area they repaired that according to their video is less than 2mm (because 2mm exceeded their limits of repair, remember). Ummmm, no - that's at least a half an inch (12.7mm) and I'm being VERY generous by giving them that - it's more like 3/4 to an inch. Ok - so they fixed it and the result is on the right image. But wait....why are the spokes in the left image going in one direction and the those in the right image going in the OPPOSITE direction (arrows in center can now be referenced)??? Uh oh, these may not be the same wheel - they're directional & they're not even showing the same wheel. Shady? I don't know - probably just a screw up but doesn't help them any IMO. Is there something to hide? No clue - only thing I know is they said 2mm exceeded their acceptable repair threshold and that's obviously not completely true or they're doing a poor job of demonstrating 2 different capabilities, cosmetic repair & structural repair. I don't care for a company to go to these lengths to explain what they do & have a question like this come up. Just me though - I don't trust wheel repair places for what I feel are very good reasons - and this just raises flags. It might be nothing though - who knows? Only they do & I doubt they're going to be very transparent about it.

Next, let's dive into that groove they carved into 5 spokes all the way around the wheel 2mm deep. Just to not get out of hand even more, we're going to limit OEM talk to GM wheels - I know their specs better than others & there probably isn't a huge difference between the big 3. GM requires fatigue testing (the rotary, radial & impact tests shown in their video - there's that word test, not inspection ) to be done with wheels at low limit dimensions. Low limit is usually 0.4mm smaller (less, thinner) on ONE side or 0.8mm brake to curb (TWO sides) ALL OVER the wheel. In other words, it's not just a groove cut deeper on the face the whole wheel has been weakened. So, what they've done is cut a GROOVE (one small area) that is a bit over 2x deeper than what GM requires for typical fatigue testing (new wheel design validation). OK - not bad. Here's what they're not telling you. The area THEY determined to be vital for structural integrity is the WORST area they could pick for 2 of the 3 tests they did. That area will really only be affected by the impact fatigue test - the flange & the face side of the spokes. The other 2 tests usually have failures occurring on the BACK of the wheels (around weight reduction pockets in rear of spokes & areas on back of wheel where spokes meet the rim). Had they really wanted to impress a person with knowledge of wheel fatigue & failure, they'd have cut that groove on the back side & made it a bit deeper & much wider then repaired & ran their fatigue tests. That doesn't even mean the wheel would have failed, either. OEM wheel validation is done on a design by design basis, meaning each wheel with a different design has to be validated (actually it's every wheel mold but that really doesn't matter). But that experiment would have definitely been more severe than what they did in the video. Also, how did they grind it down so evenly all over & not have an obvious low spot? Probably recut the face (reface) and called it a day. 2mm is an a$$load to grind & blend out evenly (you'd have seen it in the reflections if it were ground down).

Finally, let's look at that spec - SAE J2530. The AWRS says all repaired wheels meet or exceed the OEM spec:

If you click the bottom red link, you see that they tested 7 bent rims that had been straightened & all passed. Great. Here's the problem though, SAE spec is only a MINIMUM spec that OEM has to pass - OEM is actually required to pass a much more rigid internal spec that isn't available to anyone who isn't a supplier to GM. In other words, by passing the internal spec, they automatically pass SAE because SAE isn't as harsh. So I'm not really sure where the "wheels tested to OEM standards" part comes from - it's true, but only in part (half the story for the 2nd time from them). They're not exceeding anything of GMs test requirements by any stretch of the imagination - only on rotary fatigue are they even meeting it. They're falling short on radial fatigue by 10x. Impact is impact - weight & height. Hard to skew the test to show in your favor with a one & done test

I didn't read anything on their site about every repaired wheel being tested - I think what they're showing is their repair process has been tested on a sample size of wheels & they didn't fail. More like a process validation. But can you validate a repair process for each & every design, regardless of where the repaired damage occurs? Doubtful. If you repair an area that doesn't tend to fail the fatigue test, it's likely going to pass - but what if the repair is in those high-risk areas (edges of weight reduction pockets on back of spokes or in the rim/spoke union area)? It's probably going to fail or at the very least is going to increase the odds.

Reheat treatment? Hmmm. That's a new one to me unless they call heat treatment holding a weld torch in a specific area and then cooling it. Fair enough but not what I would call an exact or proven process. Heat treatment is a very controlled process & the quenching temps are vital for a successful heat treatment. Now, if they're heating the ENTIRE wheel and cooling it - forget it. No way is that safe as the OTHER non-damaged areas would become more brittle and lose their original mechanical properties. Not going to get into that because it would require too much speculation on my part. I also didn't see the subject covered on their site but I didn't dig too far into that subject matter. It was simply something you mentioned above & I'm not really trying to turn this into tit for tat either; maybe your contact told you that? I dunno.

Keep in mind, I am NOT disputing MINOR straightening (what I assume you had done) but these bends on rims, which go beyond the bead seat areas?? Not safe by a long shot. The picture below shows 2 things - a bend AND surface fracturing (area inside the rectangle has been moved/compressed past the aluminum's elasticity - it's reached its yield point & has fractured). The bend can be removed & the SURFACE ground & puttied & smoothed & polished but the INTERNAL structure has been compromised, regardless of what it looks like when it's all shined up & pretty.

But is it safe? In this particular example, probably yes, because it's on an area of the wheel that's not really load bearing. However, we're talking wheel repair here - if that was in between the inner & outer bead seats on the rim area? Absolutely not safe - load bearing. On the back or front of spokes? Absolutely not. Radial & rotary fatigue will eventually open those areas up.

Like I've said, I'm not saying ALL repair is bad - but I'm not going to say nothing when I see some potential half-truths & smoke & mirrors when I see it (not by you, but by the repair service site). If the above doesn't tell you something & what I said was standard scrapping practice by a globally known wheel maker in the racing, aftermarket & OEM segments doesn't speak volumes (and they were tight-a$$es - scrapping wasn't looked at as a good thing) then I'm not sure what else I can say will. Also, consider we're talking wheel repair - I've seen weld up repairs, etc. & am referring to really bad damage - not just the truing up of things. Maybe this particular company is better at sorting these out & not even considering them - I just can't say for sure & they aren't saying either.

I'm fine with agreeing to disagree but there are videos out there of other repairers taking a wheel that should be scrapped and reforming it using hydraulic presses with arms to isolate the pushing & pulling. Not what I'd consider straightening or minor repair by a long shot. Sorry if some of this is repetitive, long posts are at times difficult for me to keep track of the main points.

The economic impacts? Insurance companies for one (at least in wheel repair). Cheaper to repair a rim than pay for a brand new one which will probably end up being a Chinese made knock off (not original OEM) in most cases. Still shady in some cases. First heard about wheel repair in Europe then over here.

Edited September 15, 2019 by Wheelguy

Grumpy Bear · September 16, 2019

I think we are getting off track here. The subject is balance and the effect of wheel and tire manufacturing defects on balance.

NOT DAMAGE, on balance.

From Engineering Clicks

Processing after casting

After casting, wheels are (a) 100% x-ray inspected and then eventually heat-treated prior to machining. This step is followed by a pressure tightness testing before drilling valves and bold nut holes.
After a cosmetic inspection wheels are then (b) painted or varnished, this operation including a pre-treatment (degreasing, phosphatizing and/or chromating…). 3D dimensional controls (c), dynamic balance checking, (d) bending and rim roll fatigue as well as (e) impact tests are statistically performed.

Also from that site:

Casting processes

Among aluminium wheels, cast ones represent more than 80% in Europe, 85% in USA for passenger cars and light trucks, and 93% in Japan.

Their main advantages, when compared to steel or other aluminium wheels are:

A high styling versatility
Weight (equal or less than steel without styling)
Dimensional accuracy (mass distribution)
Recycling ability
Static and dynamic behavior

If there is some runout it is a correctable situation that has ZERO effect on the wheels heat treat or mechanical integrity.

AWRS is more than capable of handling run out issues and we go full circle.

A tire that requires road force balancing is a defective tire. A defective tire is an unsafe tire.

I trust the guys at AWRS to do their jobs like I trust the high school kid operating that Nuclear Reactor at Byron 25 miles away to be trained, certified and under adult supervision. Like a trust a phlebotomist not to give me AIDS. A lot more than I would trust a tire that is so dynamically and structurally compromised it needs it's own branch of specialized technology to correct in the field a product that should never leave the manufacturing plant.

Metallurgy was a mistake to get into given the topic. I hasn't a thing to do with any 'normal' situation one would encounter.

:thumbs:

Grumpy Bear · September 17, 2019

Not ignoring you Wheelguy. It's a long post and as you took the time to write it for my edification I will take the time to read it in full. Just a bit busy at the moment. Hang in there.

Wheelguy · September 17, 2019

11 hours ago, Grumpy Bear said:

Not ignoring you Wheelguy. It's a long post and as you took the time to write it for my edification I will take the time to read it in full. Just a bit busy at the moment. Hang in there.

I’m fine with leaving it alone. You’re right. Metallurgy really isn’t the point of the thread. My point was simply that repair isn’t always as cut & dried as advertised.

Look, there are MANY things being done OUTSIDE of normal manufacturing or design intent (not failing in the field). That is one thing. Balance is another AND smooth ride is yet another. The industry trend, right or wrong, in going to larger diameter wheels and tires seems to directly correlate with RFB usage, In 20+ years of experience in ONLY the wheel industry I cannot say that ONLY $hitty tires are to blame. Too many other things going on.

The above isn’t to imply that RFB is a solution to a trending issue by any means. You are right. Tires are probably the main contributing issue. However, if you can’t make a product better at the SAME SIZE TO WHICH IS NEEDED/DEMANDED what now? Does one stop making those vehicles or components? No, they aren’t going to. Does that make you wrong? Absolutely not. You simply have a higher standard. Simple as that. Does it mean GM or tire or wheel manufacturers are going to step up their game to what it was 30-40 years ago? Sadly, probably not..

They cannot make a wheel with radial runout less than 0.3mm in any direction (pilot to bead, bolt pattern to bead) or lateral runout on average less than 0.8. Those are the maximum allowable specs from GM. No clue what tires, individually must meet. The car makers cannot check them as an assembly prior to receiving them in the assembly plants so neither can the suppliers - meaning they can’t afford to let THEIR scrap pile to grow. WE CAN. THEY CANNOT.

Again, is it right? No. Has the consumer accepted it? Yep. Again, you’re NOT wrong. It’s just that the consumer and shop manager (working for GM) isn’t going to compete with your chosen tire shop. The NEW VEHICLE warranty wins out because the "REPAIR" seems to remove many of the SYMPTOMS.. You don’t have a warranty on the Buick tires or wheels. You’re a rarity in the "big diameter" years. Does that make me right concerning RFB? No. You right, no. Me wrong? No. You wrong? No. Case by case? Pretty much. They’ve found other things contribute to VIBRATION and not just balance.

It’s just not what it once was. No different than 5/100000k vs 5/60000k warranties.

Danger in the modern car making industry is determined by statisticians and lawyers - not my opinions or yours, regardless of how right or wrong we really are or how much we think we are right. They’ve got just as many smart people telling them "don’t do it".

SORRY if this seems aggressive or to the point. Not the intent - a few beers & late. Sad fact is there isn’t hard proof other than my experience or yours or anyone else that’s balanced a tire/wheel assembly in the past 20 years that tires are $hit or they’ve adjusted THEIR rules as far as what is OK. NFL seems to do it every year.

Edited September 17, 2019 by Wheelguy

Grumpy Bear · September 17, 2019

3:30 AM and I woke up thinking about this. Is that sick or what? Look, I don't find you aggressive at all. I find you pleasantly and refreshing direct and very polite and respectful while doing so. I still want to go back and read the previous post. As I mentioned I love to learn. It winds my watch. Not liking to hear something and the reaction that brings says nothing about you. Does it? Says something about me. Not liking to hear a thing doesn't make it untrue either. There is a reason the wife calls me Grumpy. :crackup:

As far as this last post. What is there that I could possibly disagree with? Nothing. It's on point and as much as I dislike the state of affairs the industry is what it is. It doesn't have a moral compass. It has bean counters and you are right about point of sale warranty issues. There is no way for either the buyer nor the dealer to know before hand when one might have the possibility to reject an assembly, and so for the OEM equipment; all one can do is either comply and follow the TSB OR bite the bullet and go out of pocket to raise the standard. I being the exacting type do just that. I understand it isn't everyone cup of tea even if it were their preference, not everyone has the means, ability or desire. Only time a dealer touches my truck/car is during a recall or major warranty work like a crate motor type issue. They are not my oil change or wheel or tune up guys.

It's that last one, desire, the sticks in my throat a bit because knowing a thing is wrong and giving in to it anyway cast an economic vote that assures not just a continuation of a unwelcome situation, it begs for it to worsen. Given them an inch.....

I have no idea if your old enough to remember that before there was a Nissan it was Datsun. When they first entered he US market the bodywork was so prone to rust that they didn't last one to three years and the 'market' tossed them out on their ears for quite some time. They went home. Upped their game and improved. I don't think they have fully recovered that loss to this day. This isn't an isolated case. Yugo was not just tossed out, the door was locked and the key buried. Ford has some body rust issues that the consumer forced to be corrected by loss of market share. It just seems this group of buyers either has lost confidence in their ability to collectively force a change or have sadly become so apathetic, wealthy or ignorant, I can't seem to put my finger on it, as to have become ineffective.

Yes, case by case and case by means. Thing is you can have all the means in the world and if your in ignorant about the possibility or knowledge of ALL the options....well....it doesn't hurt to know what is available.

lebag335 · September 17, 2019

I rolled into Discount Tire this past weekend with exactly 5000 on the odometer. Rotate and balance. One wheel/tire was almost perfect and the other three needed about an ounce. All is good!

Wheelguy · September 17, 2019

4 hours ago, Grumpy Bear said:

3:30 AM and I woke up thinking about this. Is that sick or what? Look, I don't find you aggressive at all. I find you pleasantly and refreshing direct and very polite and respectful while doing so. I still want to go back and read the previous post. As I mentioned I love to learn. It winds my watch. Not liking to hear something and the reaction that brings says nothing about you. Does it? Says something about me. Not liking to hear a thing doesn't make it untrue either. There is a reason the wife calls me Grumpy.

As far as this last post. What is there that I could possibly disagree with? Nothing. It's on point and as much as I dislike the state of affairs the industry is what it is. It doesn't have a moral compass. It has bean counters and you are right about point of sale warranty issues. There is no way for either the buyer nor the dealer to know before hand when one might have the possibility to reject an assembly, and so for the OEM equipment; all one can do is either comply and follow the TSB OR bite the bullet and go out of pocket to raise the standard. I being the exacting type do just that. I understand it isn't everyone cup of tea even if it were their preference, not everyone has the means, ability or desire. Only time a dealer touches my truck/car is during a recall or major warranty work like a crate motor type issue. They are not my oil change or wheel or tune up guys.

It's that last one, desire, the sticks in my throat a bit because knowing a thing is wrong and giving in to it anyway cast an economic vote that assures not just a continuation of a unwelcome situation, it begs for it to worsen. Given them an inch.....

I have no idea if your old enough to remember that before there was a Nissan it was Datsun. When they first entered he US market the bodywork was so prone to rust that they didn't last one to three years and the 'market' tossed them out on their ears for quite some time. They went home. Upped their game and improved. I don't think they have fully recovered that loss to this day. This isn't an isolated case. Yugo was not just tossed out, the door was locked and the key buried. Ford has some body rust issues that the consumer forced to be corrected by loss of market share. It just seems this group of buyers either has lost confidence in their ability to collectively force a change or have sadly become so apathetic, wealthy or ignorant, I can't seem to put my finger on it, as to have become ineffective.

Yes, case by case and case by means. Thing is you can have all the means in the world and if your in ignorant about the possibility or knowledge of ALL the options....well....it doesn't hurt to know what is available.

Yeah, I'm old enough to remember Datsun - my mom had one in the early 80's, and a Opel hatchback prior to that. That was near my teen years but prior to having much knowledge about the auto industry or vehicles in general. The auto industry experience came about in my 20's & 30's and that took a bit of a change in direction for me in terms of the base product in 2011. Where I'm working now, I don't have as much direct manufacturing access or areas where I can definitively learn things like I did with my former employer (the wheel manufacturer). The products which I design today consist of many different components, some made by my employer & some purchased from tier 2 suppliers. I tend to stay away from the subject because I lack a broad fundamental understanding of how it all goes together & works as well as understanding all of the different processes used to make the components - some of it could easily take a lifetime to fully understand.

Grumpy Bear · September 17, 2019

3 hours ago, Wheelguy said:

Yeah, I'm old enough to remember Datsun - my mom had one in the early 80's, and a Opel hatchback prior to that. That was near my teen years but prior to having much knowledge about the auto industry or vehicles in general. The auto industry experience came about in my 20's & 30's and that took a bit of a change in direction for me in terms of the base product in 2011. Where I'm working now, I don't have as much direct manufacturing access or areas where I can definitively learn things like I did with my former employer (the wheel manufacturer). The products which I design today consist of many different components, some made by my employer & some purchased from tier 2 suppliers. I tend to stay away from the subject because I lack a broad fundamental understanding of how it all goes together & works as well as understanding all of the different processes used to make the components - some of it could easily take a lifetime to fully understand.

Personally I think this is where forums should shine and yet seem to miss the mark. Shorten that time to something manageable and more importantly useful. I think this exchange has accomplished that goal. :thumbs:

Wheelguy · September 17, 2019

2 hours ago, Grumpy Bear said:

Personally I think this is where forums should shine and yet seem to miss the mark. Shorten that time to something manageable and more importantly useful. I think this exchange has accomplished that goal.

Thanks for hanging in there Grump. It's sometimes tough to get technical info similar to this out into the public. We need a real tire designer or engineer that isn't afraid to dish the real dirt in that area. Shed some light on why trends started or changed in that industry.

I'm having to think in my spare time about the RFB usage pros & cons. Most of it is in regards to what should be considered safe or what should be considered dangerous. Hard for me to give facts when I'm only well educated with 1 of the 2 components. I saw RFB get its start years ago when a Hunter balance machine showed up in our lab but not long after, the former employer had stopped doing business with GM & shifted supplying to their Asian bed mates (around the last major recession & tsunami stuff that shut down air bag makers). I have no firm data to back up anything related to tires but I tend to learn hard towards the larger diameter wheels & tires magnifying tire/wheel issues more so than the more traditional smaller diameters of decades past. I also know the automakers went crazy trying to chase down vibrations (out of the blue) - GM changed their mounting surface configurations in the mid to late 90's and I'm sure it continued to other areas. I can't say it was all wheel or tire related - could have been other components around the wheels & tires were changed (lightened, cheapened up or what have you). That would be up the alley of a chassis engineer & that I am not.

Grumpy Bear · September 18, 2019

Okay, I read that post top to bottom. Lot's of good stuff in there and things I did not catch as you did such as the photo's for example. Many excellent points and yet.....there is more.....

https://www.newarctech.com/training.html

https://www.newarctech.com/cm/dpl/downloads/content/69/A356_Aluminum_Wheel_Facts.pdf

Looks like they can be repaired. SAE paper down the page. (above link).

http://digital.bnpmedia.com/publication/?i=60142&article_id=630376&view=articleBrowser#{"issue_id":60142,"view":"articleBrowser","article_id":"630376"}

This is just interesting.

Then there is this. Casting are nothing like bar stock in molecular structure. Castings don't have a 'lattice" that can be dislocated. More like concrete that can be fractured. Given proper pre and post heat to the repair and passing crack testing...….

I've got feelers out to a local mold maker and his heat treater. I'm interested now. Dog with a bone interested.

Lastly let me run this by you. You seem to have an objection to 'sample' type testing. Testing seven wheels. If we tested every wheel to failure what product would you be selling? It's an impossible standard. The original wheel could have literally never been produced. There is also an implication that because GM has a higher in house standard than the SAE that the SAE standard is not adequately safe. Pretty sure it is.

This much we are in absolute agreement on. Not every wheel can or should be repaired and I think we also agree that repairs should be limited to the bead seating area and/or minor cosmetic resolutions. (I would never repair a cracked spoke) I would likely scarp the wheel before the vendor would. Bet my standard is higher yet. I'm a picky picky guy.

Grumpy Bear · September 18, 2019

0.3 - .04 mm lateral and radial wheel runout IMHO is WAY to much. You could hit that spec with a wood lathe gouge. Really ten to fifteen thousands? :rollin: