Perf n Restore

Bent Rims: RunFlats vs Non-RunFlats
Has anyone had a bent rim with non-runflats?

It would seem that the non-runflats with a more flexible sidewall would absorb more than the runflats.

Larry M

I don't think there are enough people on non run-flats

hcvone

Many people I know using non run flats including myself are running forged wheels because we had wheel issues, or don't want wheel issues.

3 Z06ZR1

The only wheel I ever personally had that bent was a forged wheel.

Bill Dearborn

The stock run flats that come on the C7 only have a reinforced sidewall on the inside of the tire. The outside sidewall is the same as a non run flat tire and just as flexible. If you attend the Spring Mountain school they have cutaway portions of the tire that you can hold in your hands and feel the difference from one side of the tire to the other. I have seen plenty of bent rims on other cars that just use non run flat tires all it takes is the right bump. That is also why there are so many wheel restoration companies in business around the country. They get plenty of business and it isn't from Corvette Owners. Every Corvette owner in the US could get 4 bent rims on each of their Corvettes and not be able to generate enough business to keep all of those wheel restoration shops in business. If I get a bent rim I keep driving on it unless the tire is losing air because of the bend or if I have torqued the wheel sideways and bent it through the hub area causing excessive lateral run out.

Bill

dparm

There are two schools of thought on this but I've never seen hard data to prove or disprove either. Even Tire Rack doesn't comment on it definitively.

Some argue that stiff sidewalls in run-flats protect the wheels since they offer more resistance to deformation from impacts. However, this lack of "give" in the sidewall could mean that the energy goes somewhere else over time, namely the wheel.

The argument for softer sidewalls it that they have more give/deformation, meaning the energy from an impact is dissipated throughout the tire better. The problem here is that on a hard impact, the deformation could be so great that the wheel actually makes contact with the road.


As far as bent wheels on Corvettes go, I think it's a perfect storm of ultra-skinny sidewalls, huge wheels, and shitty wheel metallurgy/manufacturing. Even the non-Z06 cars with more sidewall and selection of non-ZP tires still have problems with bent wheels. Heck, look at the German car forums since many of those are equipped with run-flats -- it's the same story.

Some secondary speculation on my part is that GM also wanted to optimize for performance and looks without skyrocketing the price of the car, which meant a lighter, weaker cast wheel. Cast wheels can be as strong as forged wheels, they just need to be a lot heavier to do so. The Corvette is all about performance so sacrificing some wheel durability for faster lap times & acceleration was probably seen as an acceptable trade-off.

davepl

Yup, I'm in the camp that argues a stiffer sidewall transmits the impact over a BROADER portion of the wheel itself, so it protects the wheel but transmits more shock to the suspension.

A softer sidewall (non runflat) deforms the tire more and puts a higher load on a SMALLER portion of the wheel itself, which I contend will increase the odds of damage to the wheel while offering some protection to the suspension. The softer it is, the worse it is until the sidewall collapses entirely.

That's my story and I'm sticking with it!