OFFICIAL: Bent/Cracked Wheels – Reporting to NHTSA (Merged w/previous thread)
03-08-2019, 04:08 PM
#361
It's not the compounding, it's the hard sidewalls that are very short in height. There's no place for the energy to dissipate laterally like in a higher standard side-walled tire that will react by bulging outward. Keep in mind that the RF sidewall is essentially steel with a rubber coating; that's the only way it can support being flat and still be derivable for 50 miles or so. It can't dissipate the energy laterally. Imagine taking a steel bar and laying it on the rim edge and then smacking it as hard as you can which a 20 lb sledge hammer. That's what happens when you impact a 1" ridge in a road at 60 mph. Simple physics...The cast OEM wide barrel wheel can't take that beating on the inboard side of the car. That's why the cracks and bends are on the inside rather than the outside where the edge is directly supported by the spokes.
03-08-2019, 05:25 PM
#362
Burning Brakes
Not too many options out there I see for non run-flats though. There's just the Continental ExtremeContact Sport which might be a good option and the Michelin Alpin PA4 Winter/Snow which is not what I want at all.
However, if I consider changing to the very slight smaller sizes of 275/30ZR-19 and 325/25ZR-20 I could go to Michelin Pilot Sport 4S. I've heard that's a hell of good tire and the sizes are only minutely different that the stock 285/30ZR-19 and 335/25ZR-20.
So this leaves me with 2 choices for non run-flats, either the Continental ExtremeContact or the Michelin Pilot Sport 4S and I'm leaning towards the Michelin.
Last edited by roger55; 03-08-2019 at 05:43 PM.
03-08-2019, 05:36 PM
#363
Melting Slicks
This is exactly what I'm thinking now.
Not too many options out there I see for non run-flats though. There's just the Continental ExtremeContact Sport which might be a good option and the Michelin Alpin PA4 Winter/Snow which is not what I want at all.
However, I consider changing to the very slight smaller sizes of 275/30ZR-19 and 325/25ZR-20 I could go to Michelin Pilot Sport 4S. I've heard that's a hell of good tire and the sizes are only minutely different that the stock 285/30ZR-19 and 335/25ZR-20.
So this leaves me with 2 choices for non run-flats, either the Continental ExtremeContact or the Michelin Pilot Sport 4S and I'm leaning towards the Michelin.
Not too many options out there I see for non run-flats though. There's just the Continental ExtremeContact Sport which might be a good option and the Michelin Alpin PA4 Winter/Snow which is not what I want at all.
However, I consider changing to the very slight smaller sizes of 275/30ZR-19 and 325/25ZR-20 I could go to Michelin Pilot Sport 4S. I've heard that's a hell of good tire and the sizes are only minutely different that the stock 285/30ZR-19 and 335/25ZR-20.
So this leaves me with 2 choices for non run-flats, either the Continental ExtremeContact or the Michelin Pilot Sport 4S and I'm leaning towards the Michelin.
What do you do if you get that FOUR letter word we all hate to say, flat
Rich
03-08-2019, 05:38 PM
#364
It will be a roll of the dice for you. I don't recall anyone trying to solve the problem with just a tire change probably because their wheels were already bent or cracked. In my case, I was fed up with it and opted for both the forged wheels and Continentals which is what most seem to have done. The Contis are not as flat-sided as the run-flats and some folks don't like the appearance vs. stock tires but I think it's minor. Good luck with whatever you decide to do.
03-08-2019, 05:39 PM
#365
03-08-2019, 05:43 PM
#367
Burning Brakes
Someone mentioned overinflating the tires by about 5 lbs and let the shocks absorb the pounding. As a 4 bent wheel car I have done that. Moved the pressure from 30 to 35 and so far so good. I took a road trip from Tucson to Vegas and back without problems. Anymore bent wheels and forged for me.
03-08-2019, 05:52 PM
#368
Burning Brakes
I may be the first one to give this a test here. My car has less than 3K miles on it. I've had no problems but I will thoroughly visually inspect and use a dial indicator on my wheels before putting the new non run-flat tires on.
03-08-2019, 06:05 PM
#369
Burning Brakes
03-08-2019, 07:13 PM
#370
Team Owner
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Someone mentioned overinflating the tires by about 5 lbs and let the shocks absorb the pounding. As a 4 bent wheel car I have done that. Moved the pressure from 30 to 35 and so far so good. I took a road trip from Tucson to Vegas and back without problems. Anymore bent wheels and forged for me.
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joemessman (03-09-2019)
03-08-2019, 07:32 PM
#372
Think about it. A hard sidewall tire is transmitting a huge shock to the wheel. Over-inflating the tire makes it harder. The energy will transfer to the wheel before the shock absorber even has a change to think about what just happened. Conclusion: harder tire will make the impact to the wheel even worse. Physics is physics - you can't fool mother nature.
03-08-2019, 07:43 PM
#373
Instructor
Our roads in Michigan are bad. Really, really, bad. Root cause is the weight of the trucks. We allow the most heaviest, not sure how to read all the weight laws. But federal exemption is 164,000 lbs. Alaska is the only one that does not have limits (everything most be froze) They just add more axels to spread it around. Kind of like the question what is heavier a ton of feathers or a ton of lead? Anyways even if they were to start to fix the roads. They can not do all of them at once. They will do them the cheapest way. They always ask if you want one mile of really road, or 5 miles of cheap new roads which will not last. Each past administration, just past it to the next for so long. Now they will add more tax to the gas. When it is done it will be about $0.75 tax on the gallon.
I do believe that the GM has pushed the envelope in the handling of the GS and above. Stretching everything to the limits. I do not think the tire technology was finally able to catch up to this year with the new All Seasons run flats. These only came out a few months ago. Since all the GS and Zs came with summer only tires, I wonder how many times they were drove below 45 degrees. I think this also contributed to the wheel problem. A lot have said they never drove below 50 degrees and still had problems. That the tires were too hard when cold and transferred more of the shock and load to the wheels. The weakest link in the system.
Next I learned about staggered wheel set ups. That there is a aspect ratio front to back. So if you want to change size (diameter) of the front tire you have to change the back tire to the ratio. There are not that many tires that you can just do that. After much searching . I found these. That have same diameter with in a tenth or two. Still a staggered set up 18 X10 wheels in the front and 19 x12 wheels in the rear.
Michelin Pilot Sport A/S 3+ ZP 95Y 500AAA 275/35ZR18 5rib for the fronts.
(same weight as originals, same diameter as original well with in .2 of an inch.) Meaning going down 1 inch on the wheel will give me an extra half inch more of the stiff run flat side all around the rim.
That would be on 18X 10 rims. But over all height with tire mounted is the same as originals. Same offsets.
Michelin Pilot Sport A/S 3+ ZP 101Y 500AAA 325/30ZR19 6rib for the rears.
(a little more weigh then originals, same diameter well within .1 of an inch.) Meaning going down 1 inch on the wheel this will give me an extra half inch of the stiff run flat side wall around the rim.
That would be on 19X 12 rims. But over all height with tire mounted is the same as the originals. Same offsets.
All 4 tires also have a slightly higher weight load load rating than the summer tires.
Seen pictures of a couple other drivers using about the same set up. Trouble trying to go back and find what you viewed the day before, so many tire posts.
These tires are slightly narrower than the originals. I will to trade off some performance, for protection on bad roads. This would be on forged rims. If anybody see something that is wrong with this or causes problems with any of vettes systems let me know.
I do believe that the GM has pushed the envelope in the handling of the GS and above. Stretching everything to the limits. I do not think the tire technology was finally able to catch up to this year with the new All Seasons run flats. These only came out a few months ago. Since all the GS and Zs came with summer only tires, I wonder how many times they were drove below 45 degrees. I think this also contributed to the wheel problem. A lot have said they never drove below 50 degrees and still had problems. That the tires were too hard when cold and transferred more of the shock and load to the wheels. The weakest link in the system.
Next I learned about staggered wheel set ups. That there is a aspect ratio front to back. So if you want to change size (diameter) of the front tire you have to change the back tire to the ratio. There are not that many tires that you can just do that. After much searching . I found these. That have same diameter with in a tenth or two. Still a staggered set up 18 X10 wheels in the front and 19 x12 wheels in the rear.
Michelin Pilot Sport A/S 3+ ZP 95Y 500AAA 275/35ZR18 5rib for the fronts.
(same weight as originals, same diameter as original well with in .2 of an inch.) Meaning going down 1 inch on the wheel will give me an extra half inch more of the stiff run flat side all around the rim.
That would be on 18X 10 rims. But over all height with tire mounted is the same as originals. Same offsets.
Michelin Pilot Sport A/S 3+ ZP 101Y 500AAA 325/30ZR19 6rib for the rears.
(a little more weigh then originals, same diameter well within .1 of an inch.) Meaning going down 1 inch on the wheel this will give me an extra half inch of the stiff run flat side wall around the rim.
That would be on 19X 12 rims. But over all height with tire mounted is the same as the originals. Same offsets.
All 4 tires also have a slightly higher weight load load rating than the summer tires.
Seen pictures of a couple other drivers using about the same set up. Trouble trying to go back and find what you viewed the day before, so many tire posts.
These tires are slightly narrower than the originals. I will to trade off some performance, for protection on bad roads. This would be on forged rims. If anybody see something that is wrong with this or causes problems with any of vettes systems let me know.
03-09-2019, 08:04 AM
#375
Instructor
First I did NOT know about the wheel and other problems when buying the Grand Sport. Was trying to find one in Watkins Glen Grey since they discontinued color with the options I wanted. Which I had to have and which I could live with out. So many options, and yet none in my state.
Second was the price.
Third I did not know about this forum.
and lastly the dealer in another state never offered it.
Second was the price.
Third I did not know about this forum.
and lastly the dealer in another state never offered it.
03-09-2019, 09:36 AM
#376
Because the wheel coverage will only replace the bad wheels with new OEM ones which will only repeat the problem. Plus, it's often a hassle when the insurance companies start to tell you it was due to a road hazard and beyond the scope of coverage. Even if they do cover them it's a hassle to keep putting up with recurring drill of the process of replacing them. I suppose it saves money for awhile until they start to push back on multiple claims but for me it just doesn't solve the problem, it only keeps yo in a groundhog day-esque cycle of replacing wheels.
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joemessman (03-09-2019)
03-09-2019, 10:09 AM
#377
Heel & Toe
I did not buy wheel coverage because in 20 years of buying/leasing new cars I have never once had so much as a flat tire, let alone curb rash or a broken rim. I guess I can consider myself lucky and this was just my time to pay up.
From now on, I will strongly consider it especially if my next car is stretching the limits of the design as the GS did in mating these run flats with a wide cast wheel.
From now on, I will strongly consider it especially if my next car is stretching the limits of the design as the GS did in mating these run flats with a wide cast wheel.
03-09-2019, 10:30 AM
#378
Racer
I totally agree with tertiumquid. Dealing with insurance companies is difficult and then you still have the same potential problem! The question is how widespread is this problem? Is Chevrolet going to address it in the future when they get more complaints!
03-09-2019, 10:36 AM
#379
Race Director
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