dparm

Woke up early and drove out to Discount Tire's warehouse in South Bend to get new tires installed on my GS. Turns out BOTH left wheels were bent and had run-out of about 0.25-0.33"!

Some quick Googling on this site seems to indicate that the combination of small sidewalls, but also overly-stiff ZP ones, leads to a lot of bent wheels on this car...but I want to make sure it's not just confirmation bias. Even the guys at Tire Rack speculated that the ZP tires could contribute to it -- the sidewalls are so stiff that impacts will transmit a lot more energy to the wheel than the non-ZP.

If I replace those two wheels, am I going to find myself in this same position again next year? It's quite frustrating as the car only has 8,000 miles on it. Would moving to non-ZP help provide some extra cushion as well?

Otherwise I think I will just replace all four with something forged and strong (Forgeline, Cray, Finspeed, etc).

AORoads

From what I've read, there does seem to be issues with the new/newer wheels. Maybe it's the tires, the wheels, the roads or even the driver, but it can't hurt to buy better wheels--except in the wallet. Good luck with it. Here's hoping you don't bend one of those!

dparm

Are the factory wheels forged? I would have hoped they were, given the sporting credentials...

Even C&D's long-term test GS had several bent wheels:
https://www.caranddriver.com/reviews...-update-review


WHAT WENT WRONG: Nothing went wrong that was the Grand Sport’s fault. After two and a half months in the fleet, our blue Vette developed a moderate vibration at speed. We pulled the wheels and attempted to rebalance them, only to learn that all four wheels were bent. Michigan roads having taken their toll, we paid a wheel-repair specialist $480 to straighten three wheels. The left-rear wheel was cracked and a replacement 12-by-20-inch wheel ran $619 at the dealer; feeling lazy, we also spent $20 to have the dealer swap the 25-series, run-flat tire because not having to muscle tires that big off and on a wheel is worth every bit of a couple of sawbucks.

orca1946

I have read that in the track mode, wheels are bent more than in the other modes.
Could that be part of the problem Also somewhere i also read that all season regular tires were going to be available for our Vettes. Has anyone found these yet?

dparm

I keep the suspension in a soft setting around town. I only stiffen the suspension up when I'm on the track.

Tire Rack does not show any A/S choices for the GS/Z06 unless you move to non-standard sizes.

oemtech

I have had 2 bent wheels repaired..$125 a pop. If they need more than straighten they send them out. Turn around takes about week.

dparm

I'm not sure I trust that considering I take the car to the track. Straightening = heat stress = weakening.

Foosh

It's not common at all on Z51 wheels, in fact don't remember hearing it here. It has been reported by folks here with GS wheels on more than a few occasions, and to a much less extent w/ Z06 wheels. While the GS Cup wheel is a very attractive design, the spokes are much thinner and more spaced apart, and it certainly looks less structurally strong than the other designs.

None of the OEM wheel selections on any model are forged. They are all cast wheels, but of decent quality.

2K14C7

OK I’m confused. Behind Tadge it clearly shows the Z51 wheels to be forged???

dparm

Just because it looks weaker doesn't mean it necessarily is. With good FEA and manufacturing processes, you can get some pretty crazy designs that are still VERY strong.

But yeah, it sucks that these wheels are notoriously soft. I doubt the ZP tires are helping either.

The two right wheels were not perfectly round either but were still within Tire Rack's spec -- and they said that bigger, wider wheels like these are rarely perfect anyway, hence we use wheel weights and balancing machines.

TEXHAWK0

How do you know the wheels did not already have excessive run out when you bought it?

dparm

There's no way that I put 8,000 miles on the car with that kind of run-out, and on the same side of the car. It would've been immediately noticed at the factory when they were mounting tires and balancing them.

Foosh

That's certainly true, but there have been more GS wheels reported bent than any other design on this forum. Most of the "crazy designs" are forged mono-blocks, which are crazy expensive, but are also both the strongest and lightest wheels on the market. None of the OEM designs are forged mono-blocks.

I think that may be an old video, and perhaps they were at '14 MY intro. The wheels on my new '18 are stamped "Diecastal," which is a Chinese manufacturer that only builds cast aluminum wheels.

dparm

Shame they didn't do forged wheels like some other sports cars.

Are the Z06 wheels any stronger? I am referring to the standard spiderweb ones, but also the split-5 spoke "twist" model that was optional. Obviously they are the same size as the GS wheels so if it's possible to get something stronger without going crazy on Forgeline or CCW, I'm all for it.

It also blows my mind that the ZL1 1LE gets forged wheels and we don't. It's tempting to just buy a set of those for half the cost of Forgelines. They'll fit and stick out a bit more, especially in front (11" vs our 10").

Gearhead Jim

For the record, I hit a protruding manhole cover in our Z51, with the suspension in Tour, and later when being rebalanced, found one rear (chrome) wheel slightly bent in the barrel, the actual rim edges were ok. Tire (factory MPSS runflat) was undamaged. Insurance insisted on straightening instead of replacing, our local Tech said he was fine with that because the bend was so slight. It's also possible that the wheel came from the factory already bent, no way to know.

Conversely, about 5k miles later with our new A/S3+ runflats on a set of factory painted wheels, I hit something and never even noticed it until noticing the tire damage days later. The tire was obviously toast even though it was still holding pressure (!), but the wheel was not bent- the shop at Spring Mountain and Discount Tires in Chandler AZ both inspected and spun the wheel, said it was fine. Perhaps that's because the impact was centered right at the end of the spokes, where they give maximum support to the rim. See pic.

Prior to this I had over 200k miles on Corvettes without over bending a wheel and only one damaged tire- a sidewall cut from a sharp rock that rolled out onto the road.

Avanti

I've never understood how such skinny sidewalls (and wheels), irrespective of tire type, could survive in many of our road environments. There is simply not enough mass/structure... of any kind between the pothole and the wheel.

Luke42_02

Larry M

You're not spending much time over at the Z06 section, owners including myself are busting wheels all the time. They're awful wheels, too bad I absolutely love the look

Foosh

You're right I don't spend any time over there, although I've heard of examples of bent Z06 wheels as well. The sturdiest design of all the factory wheels seems to be the Z51.

The only true forged wheels are forged mono-blocks. Even "rotary-forged" is actually a cast wheel, where the molten aluminum is spun in the mold. By contrast, forged mono-blocks are cut out of a solid block of aluminum formed at incredible pressures, which allows them to be stronger, thinner, and lighter all at the same time. The downside is that they start at over $4K per set and go way up from there.

oemtech

I don't track my car so that is not an issue for me.