Foosh

Those other sports cars you refer to are way north of $70K. The C7 is certainly a bargain in performance bang for the buck, but you can't expect to find high-end, forged mono-block wheels as OEM on a car in this price bracket.

ZP tires are not the problem, and offer more wheel protection because of the stiffer sidewall. Low profile, non-ZP tires provide far less wheel protection, as the softer sidewalls are much more likely collapse into a pothole damaging a wheel.

themonk

'14 Z51 with gloss blacks here.

I hit a pot hole so hard (30 km/h) that it killed the front tire, blew a hole in my Continental, didn't damage the rim at all, back hit it too but didn't blow the tire and it wasn't damaged either.

Kevin A Jones

Obviously bending/breaking C7 wheels is not the norm, however it does happen on occasion.
Z51, GS, Z06 and ZR1 suspension, brakes, tires and wheels seem more designed for tract performance as opposed to running around town hitting potholes and speed bumps.

CW4L

Sadfully GM put cheap wheels on these monsters. CLl or text us for some great promos on our forged wheels which are lighter, stronger, track worthy and best of all wont bend!!

440-915-6166

SLOWRYDE

I suspect the aggressive wheel camber set from the factory is the causative factor. This tilts the wheel and therefor the stress point onto the inside edge of the barrels and upon impact is causing the wheel to deform. A typical wheel gets the benefit of the entire width of the barrel to absorb shock. Additionally, a wheel is stronger when the stress is spread out across a larger span than concentrated on the edge. It comes as no surprise that the most affected are Z06's and Grand Sports considering these two models come from the factory set up with this aggressive camber setting. I ran Cup Wheels on my C6 Grand Sport and Z06 for years without an issue. I am keeping my fingers crossed on my C7 GS cups..

Walt White Coupe

Even "rotary-forged" is actually a cast wheel, where the molten aluminum is spun in the mold.

Foosh, That is not what "Rotary-Forged" means. When GM says the wheels are "forged" they mean they are Rotary-Forged = flow-forged = spun rim = rim rolling, all different terms for the same process.

dparm

Foosh

They are not forged mono-block wheels for just $1K more, which are the only true forged wheels. Terms like "rotary-forged" have been invented to fool folks into thinking they have forged wheels.

As I said above, rotary-forged wheels are just cast wheels, where molten aluminum is poured into and spun in the mold. Sure you can get those for maybe $1K more, but actual forged wheels will cost you $3-5K more. If it's not a forged mono-block, it's just some sort of cast wheel. Some cast wheels are better than others.

As for the ZP debate, there's a lot of out-dated info out there. PSS ZP side walls do flex, otherwise you wouldn't get equally superior handling and skid-pad performance on the PSS ZP as you do on the non-ZP. You can see them flexing as the car sits still on your garage floor.

Ride-quality may have been noticeably harsher on ZPs a decade ago, but that's no longer true. I have a winter set of Michelin AS3+ non-ZPs, as well as my OEM PSS ZP set. I've swapped them back between winter and summer for 2 seasons now, and I just put my PSS ZP set back on last weekend. I do not detect a significant difference in ride quality between my Michelin ZP and non-ZP set.

At any rate, the "cumulative stress" argument is irrelevant in the case. Even if true, that kind of "stress" get's evenly applied to all 360º of all 4 wheels as they are rolling. It's heavy impact damage that's bending wheels, and non-ZP tires make wheels more susceptible to damage to from that.

joemessman

Best wishes trying to get some of these people to believe what you are stating, which is correct I might say, but they are also changing their oil every 3,000 miles.
I have also had both the ZP and non ZP tires on my car and there is no difference in ride and road noise. I did this as an experiment for my Discount tire friend. My wife can hear and feel everything, and if she can't feel and hear the difference nobody can.
If anyone says there is it is therefore some type of "wishful thinking" effect.
(I think that when some purchase new tires and hear less road noise they tend to forget new tires are quieter, as the tread hasn't worn down)

Foosh

Thanks Joe, many myths may have been, in part, true at some point in the distant past. That's certainly the case with run-flat tires because when they first debuted years ago, they were much harsher. The problem with myths is that once established they get passed from generation to generation and never seem to die. The same is true w/ oil change intervals.

pdiddy972

I agree suspension is likely involved. Could explain why GM is making all the new MRC calibrations available.

robert miller

The c7 factory wheels are just **** to me in weight & being able to take even a some what small pot hole. That is why after replacing a stock rim I went with lite weight forged rims on the car... Robert

Foosh

True, but if GM decided to put forged mono-block wheels on every C7, folks would be screaming about the $5K+ price increase. It's important to keep in perspective that what GM is offering in the Corvette line is a car that far undercuts the price of it's competition. That involves trade-offs.

Personally, I prefer it that way. I'd rather make the choice myself to pay $5K for a set of wheels if I need the light weight and strength of forged mono-blocks, and I'd rather choose my own design rather than what GM decides my expensive wheels should look like. The average Corvette owner does not want or need forged mono-blocks.

SLOWRYDE

Foosh

I don't know . . . see post #27, which is what I was responding to. It was my term for what I thought he was trying to say, and which I did not agree with.

Walt White Coupe

I guess I have to repeat this since you didn't get it the first time.


Even "rotary-forged" is actually a cast wheel, where the molten aluminum is spun in the mold.

Foosh, That is not what "Rotary-Forged" means. When GM says the wheels are "forged" they mean they are Rotary-Forged = flow-forged = spun rim = rim rolling, all different terms for the same process.

Foosh

I saw it earlier, just ignored it. I guess I have to repeat that they are not true forged wheels. It's just a clever marketing term. They are just higher-quality cast wheels.

2K14C7

Here is some pertinent info.

One-Piece Cast Wheels
This is the most common type of aluminum wheel. The casting of wheels is the process of getting molten aluminum inside a mold to form a wheel. There are different ways this can be accomplished and although it sounds simple, this is truly an art when done properly.

Gravity Casting

Gravity casting is the most basic process of pouring molten aluminum into a mold utilizing the earth's gravity to fill the mold. Gravity casting offers a very reasonable production cost and is a good method for casting designs that are more visually oriented or when reducing weight is not a primary concern. Since the process relies on gravity to fill the mold, the aluminum is not as densely packed in the mold as some other casting processes. Often gravity cast wheels will have a higher weight to achieve the required strength.

Low Pressure Casting

Low pressure casting uses positive pressure to move the molten aluminum into the mold quicker and achieve a finished product that has improved mechanical properties (more density) over a gravity cast wheel. There is a slightly higher production cost over gravity casting, but low pressure casting is the most common process approved for aluminum wheels sold to the O.E.M. market. Some companies offer wheels that are produced under a higher pressure in special casting equipment to create a wheel that is lighter and stronger than a wheel produced in low pressure, but there's a higher cost associated with the process. Low pressure cast wheels offer a good value for the aftermarket while still maintaining strength and a lighter weight.

Spun-Rim, Flow-Forming or Rim-Rolling Technology
This specialized process begins with a low-pressure casting and uses a special machine that spins the initial casting, heats the outer portion of the casting and then uses steel rollers pressed against the rim area to pull the rim to its final width and shape. The combination of the heat, pressure and spinning create a rim area with the strength similar to a forged wheel, but without the high cost of forging. Some of the special wheels produced for O.E.M. high performance or limited production vehicles utilize this type of technology resulting in a dramatic reduction in wheel weight while enhancing structural rigidity vs. a standard cast wheel.

Wheel manufacturers define this process in many ways. O.Z. Racing flow-formed wheels like the Hyper GT HLT, for example, are created using their proprietary High Light Technology (HLT), a combination of flow-forming and other technologies directly derived from experience gained during the production of their Formula One and Indy car wheels.

CNC Mill
In forged wheels, computer numerically controlled (CNC) mills add the cosmetics and the bolt circle to exacting tolerances.

Forged
The ultimate in one-piece wheels. Forging is the process of forcing a solid billet of aluminum between the forging dies under an extreme amount of pressure. This creates a finished product that is very dense, very strong and therefore can be very light. The costs of tooling, development, equipment, etc., make this type of wheel very exclusive and usually demand a high price in the aftermarket.

SLOWRYDE

Foosh

I don't think camber has anything to do with it.