Whats the technical harm of switching a pair of unidirectional tires? A non vette friend thinks unidirectional is just a marketing ploy. I can tell the pattern would be reversed, but on dry pavement, he says who cares?
joe

 

You can't put fronts on rear and vice versa.Different sizes and all that.

 

I don't think rotation is the question, the belt plies in the tire are designed to retain adhesion when the tire is rotated in one specific direction. You can damage the internal construction of the tire. The water clearing design will not function properly and you will hydroplane in a blink.

The guy that reverses the tires direction is an idiot and should be removed from the gene pool.

 

X12

 

Don't do it !
Tires will wear , more noise and vibration , they'll essentially resist rolling smoothly .

 

And will be removed from the gene pool quickly when he makes that decision.

 

I agree they should not be reversed, but a few months ago the same question was asked and the consensus was it was OK. Sometimes the answers on this forum are confusing and inconsistant. Any real tire engineers out there?

 

Yes, this issue has been discussed here about 400 times, and I don't think everyone ever agrees.

Seems that most feel it is ok to reverse the direction of tires now though. It was supposedly a bad idea with older tires, but newer tires can supposely take it.

I don't know the real answer, but I feel you can't go wrong if you do NOT reverse the tires. I don't see a real need to do it anyway. If the car is aligned well, you will get the same amount of mileage out the tires regardless, reversing side to side really should not make a worthwhile difference in tire life.

Rotating back to front might help extend the life of all 4 tires together, but of course on a C6 we cannot do that anyway.

As for "directional" patterns... I'd think it technically would not make a difference on dry pavement, but... do you have a trick to stop the rain??? If so, I'd like to know it! Don't fool around with rain... one freeway spin out could mean getting flattened by a tractor trailer ... respect thy directional tire pattern.

 

I still don't agree with this. That's why they are called unidirectional, instead of omnidirectional.

 

Tires that are designated as directional are that way because the tread pattern is designed to pump water from the center of the tire to the outside of the tire. Running them backwards pumps water to the center of the tire and will cause hydroplaning. Not something you want to do with a tire as wide as we use.

 

also if the tire maker was thinking that his tire was only going to spin in one direction do you think that he tested it much going the wrong way.

 

A lot more then you think they would

 

Don't think it is a marketing ploy, but reversing directions on DRY pavement is probably not going to make a difference. The only reason to have tread on a street tire is to channel water out from under the tire. The last question on this subject pointed out that if you track the car, you might be able to get more wear out of the tire by changing sides of the car if there are more turns in one direction than the other.
I think reversing the direction of the tires causing the tire to fail is no longer true with modern tires. I have GYF1SC tires on my Z06 and I have switched sides of the car to even out tire wear with no problems at all. If you are wanting to rotate and want to keep the direction correct, you can always take the tires off the wheels and reverse them.

 

I saw an article where they decided to find out how this would affect motorcycle tires on the track. Of course, it was dry out, and the riders couldn't tell weather the tire was on backwards or not. They could only conclude that the only reason to not run them backwards is if you were going to run in the wet.

 

just drive in reverse and change the gearing

wtf

 

we flip race tires all the time, just not a good idea in the dry

 

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A Goodyear engineer explained similiar info to me

 

If you meant "wet" then

As said above, the tread is strictly for wet pavement. A directional tire has treads to push water away. If the tire is used backward, you will not know the difference until it rains. I've driven with them on backwards in the rain and it's not impossible but not recommended.

The tire is designed to take loads in BOTH directions. THink about it. The load on a rear tire when you are accelerating is exactly the opposite of the load on the tire when you are braking. If it was only designed to accelerate, they would fall apart on braking. Or the other way around. The only solution is to built the carcass of the tire for BI-DIRECTIONAL use. Which is different from the TREAD being UNI-DIRECTIONAL.

We who track our cars generally wear out the left sides of the tires more quickly because most tracks are run clockwise and therefore have more right hand turns. We can generally get another couple of track days from them by reversing. Unless we're running in the rain, we have no concern about the tread pattern and we usually dispose of the tires before we use them in the rain mounted backwards. Having said that, I have driven home from the track in the rain on tires that were not only almost bald but mounted backwards. Once they're almost bald, they probably don't handle any worse whether they are forward or backward.

So for those who think the gene pool will be better without me for doing this, most of the other track dogs I know will have to go too.

 

The tires on my C5 were installed backwards. I didn't notice for about 3,000 miles. One day I did and had them swapped. Couldn't tell one bit of difference. Drove in rain, etc.

Does it make a difference? Probably. Is it an enormous difference? Not in my experience.

These were PS2s, so perhaps the stock runflats are more of a problem.

 

Goodyear Gatorbacks were the first unidirectional tire designed for hydroplaning resistance. A magazine ran a test to see how effective they were by running the tire over a plate glass with standing water with the tire mounted "correctly" then "incorrectly". Using high speed photography, more of the tire was in contact with the plate glass (less hydroplaning) when the tire was mounted incorrectly. So much for theories and the gene pool...