Z06-Nomad

This may be a borderline dumb question, but better safe than sorry.

When mounting the stock GY Supercar tires they have a “ “THIS SIDE FACES OUTWARDS” and “ THIS SIDE FACES INWARDS” but can they spin in either direction? In other words, you can swap your front and rear tires right to left and left to right if you want, correct?

I’ve bought many more motorcycle high performance tires than car tires in my life, and they have a definite direction of rotation. Also if I remember correctly didn’t some C4’s require 4 separate and distinct tires because they were asymmetric AND rotation specific?

Just want to triple check. Thanks.

rwd

The owner's manual says they are not to be rotated. However, some people have switched them side to side while keeping the outward side out.

As you know, usually non-rotation is keyed to a tread intended to disperse water. The S/C tread is so heavily biased toward dry performance, that's not really an issue. There's really only one row of tread blocks that are V'd, and the angle's almost imperceptible. It'd probably make some difference in the rain, but not much.

You're correct about the C4 issues.

jerryv

Don't rotate the tires. They are directional and asymetrical.

Z06-Nomad

If this is so. Where are the markings? How do you know which is Left and which is Right?

Not trying to be a smartazz. The tires are off the rims and are "all mixed up" in a big stack.

ruking1

No, I don't think your question is dumb at all. There are no lefts and no rights once you observe the "this side out instructions" on the GY SC F1's. While I have heard of folks changing from left to right and right to left, the manual says not to do it. Personally, I would do it if I had nothing to lose. (uneven wear, one tire wears faster than another, flat, spare, etc)

The inside tread (app 1/2 of the whole tread) is the one that is designed for the water chores.


[Modified by ruking1, 10:48 AM 11/22/2002]

pdvale

The Z06 tires can be put on either side of the vehicle. I don't know if rotating left to right really makes any sense or not.

Paul.

Z06-Nomad

Thanks for your reply.

One case I can think of that it would be a good idea, is if you were inclined to do track days. Depending on track direction your outside tires always take a bigger beating than your inside tires. If you tend to go to the same track over and over switching them around would help extend their life considerably. (But, of course, I never take my car to the track, as that could affect my warranty ;) )

rwd

That's the reason people switch them. I suspect the reason the tires don't have rotation arrows is that there's so little directionality in the tread it basically makes no difference. The owner's manual is specific, however.

FLYNLO

As some have said in this post, there is NO directionality to the F1 Supercar tires. They just have to be mounted a with the proper side out(or in).....simple as that!

kwillmorth

Eagle F1 SC tires are ASSYMETRICAL but NOT directional, so yes they can be swapped from one side to the other. I do this at the track every time we take it out, as most tracks are right or left turn biased, thus wearing one side faster than the other. I (and many others) have done this many times, and driven hard at speeds in excess of 137mph, and have had not a single problem. Goodyear confirms that this is acceptable for these tires by calling their tech line at 1-800-387-3288. Any dealer with a knowledable rep will also confirm that the tires are not bothered by being swapped left-to-right.

The Owners manual specifically addresses rotation, as in 4 wheel rotation, which cannot be done, for obvious reasons. Further, the owners manual is not specifically addressing the ZO6, it addresses the C5 in general, which uses symetrical DIRECTIONAL tires (Run Flats). These cannot be reversed (side-to-side), as the water channels would not function properly. However, I have also seen these reversed at track events on dry pavement to increase tire life, again with no ill effects. They just have to be put back on their correct corner before any wet conditions occur.

A very similar tire to the F1 S/C's is the Pirelli P Zero Assymetrico's, which have the same basic tread design. They too can be swapped side-to-side, but are mounted to the rim only one way. :cheers:


[Modified by kwillmorth, 5:02 PM 11/23/2002]

Z06-Nomad

Thaks to everyone who answered the post. Judging from the many incorrect answers, it appears I was not the only one confused on this! :cheers:

rwd

No offense meant, but if there were no directionality at all, there'd be no reason to return them to their correct positions before wet conditions occur.

The tread has some minor directionality. Reversing it won't affect dry performance, but it will affect water dispersion slightly. It's just not enough to justify marking it directional, and that's what the techs are going by.

Brutus0725

Discount tire told me not to rotate mine. The tech told me once they are beaded in, going in one direction, they should not be changed. He couldn't really tell me why though. If goodyear says it is ok, then I would change them. I will do mine this weekend.

SWCDuke

There are two reasons that tires are directional - a directional tread pattern and construction seam strength. Years ago when the Gatorback first came out Road and Track tested them running both ways (new tires) and the wet braking when running "backwards" was barely outside the confidence window, so the actual quantifiable difference in wet braking and handling performance when running the "right" and "wrong" direction was marginal at best.

The Yokahame A008RS is directional, but does not have a directional tread pattern - just asymmetrical. At one time they were available in "A" and "B" versions for proper rotation direction on each side. This is because the construction seam technique was able to take more load in one direction than the other. I used these tires on the track and rotated them side to side to even out the wear and never had any problems. Late in production the "B" version disappeared, so I just ran the "A" on both sides.

As previously stated, the F1 Supercars are asymmetrical, but not directional and there should be no problem rotating them side to side. Some have also flipped the tires on the wheels due to camber wear (usually due to tracking the car) in order to get a little more out of them, and I don't recall anyone reporting problems with this practice.

Modern owners' manuals would probably be half the size they are currently if all the "warnings" and "cautions" inserted by the lawyers, many of which are just good common sense, weren't there.

Duke

kwillmorth

To clarify: The only tires you must return to their proper corners are the directional tires, such as the Yokohama's mentioned. The tread design on those specific tires pumps water in one direction only and may hydroplane in the other. The F1's SC's do not have this problem, thus do not need to be re-reversed at all.

Here's the deal. We all know that these tires are Assymetric (that's visible). If they were also directional, they would be sold as right and left side as well, since you could not mount them reversed to make the other side work. Not many tires are both directional AND assymetirc, as this would require the manufacturer to produce a different tire for every corner on the car, not a very good idea from an inventory standpoint.

In the early days of radial tires, rotation could be problematic (read: Michelin's first efforts). Reversing them can make them act funny, or go "square". In early tire rotation advice, cross-rotation was a no-no. Modern radial tires just don't have that problem any more.

Swapping left to right with assymetric tires is now common practice. Even the Tire Rack shows this in this article (see rotation pattern E):
http://www.tirerack.com/tires/tirete...ral/rotate.htm

The tires on my car today (second set) ran 1,200 street miles, 2.5 hours of track time, then reversed, ran 2 hours of track time, driven 2,500 miles in all sorts of yuck from LA to Wisconsin, auto-x'd once, reversed, auto-x'd again, and now driven another 1,500 miles. They are pretty shaggy now, to replaced this spring, but wear is even left to right and I have had zero problems. My first set were abused and reversed, abused and reversed, abused and reversed. I don't take risks at 137mph on road race tracks, if they acted funny on any level, I would have put them back and not reversed them again, ever.
:cheers:


[Modified by kwillmorth, 7:29 PM 11/28/2002]

GRB

Actually in the name of accuracy, Michelin was the only mfg to NOT have that problem. In the 70s no other tire mfg in the world knew how to bind rubber to steel. As a result the other mfgs tried putting other belt material above and below the steel belt. The BFG 990 radial actually had 9 plies in the crown (tread area) of their radials. This resulted in heat build up that would eventuall destroy the tire. Reversing the rotation seemed to magnify the problem.

Michelin was actually delighted to inform the world that their tires could be rotated in any fashion whatsoever. Even Michelin's earliest American radial, the Michelin X and X Stop (for imports) were a 2 + 2 constuction. Usually rayon and steel. These first tires were sold through Sears only.

Michelin did stipulate that cross rotation might result in a slightly rougher ride for a period of a few thousand miles due to each wheel posistion's slightly different wear characteristics.

Just for the record, BMW and Mercedes used to (and may still) advise against tire rotation for just that reason.

Lack of tire rotation has probably invalidated more milage warranties than all others reasons combined.

kwillmorth

You're right, I remember that now. Thanks for the refresher! :cheers:

MY 2002 Z06

The stock GY tires are NOT directional as some folks above indicate. If you look at the tires off the car side by side, you will see no difference. Hence, you don't need to buy "left" or "right" side specific tires. If I handed someone two brand new GY Supercar tires and asked them to tell me which is left and right, there is no way they could do it since there is no such thing.

I swap my tires side to side on occasion depending on how many track miles and which track I am running to keep some sort of "balanced" wear from left to right. For normal street driving, this probably is not beneficial.

Hope this helps your decision.

rwd

The SC tires are not directional, but the tread has some minor directionality.

It may be the original concept was to have directional tires, but the difference in performance was so minimal that GY and/or GM decided to avoid the difficulties and costs associated with making, selling or using two distinct versions.

It can be seen by putting two SC's side-by-side with the inner 'wet' portions touching. One tire will have mild V'ing on the inside- a characteristic of directional high-performance rain tires since the first Gatorbacks. It will be the tire on the right (the driver's side as mounted on the car).

In any case, the passenger side will always be backwards in that respect.

As for whether reversing the tires on the rims makes a difference, if it doesn't decrease both wet and dry performance by some small degree, however unnoticeable, then the two patterns are only a marketing device.

The effectiveness of rain tire tread patterns can be disputed, but iirc the problems with Gatorbacks were attributed not so much to having all four tires reversed (which degraded performance both in stopping and cornering to some extent), but to having just one or two tires on the same side were reversed. Loss of control and accidents were, correctly or incorrectly, attributed to the resulting imbalance. FWIW.

GRB

If the tires were directional to a degree that effected performance they would HAVE to be marked FOR LEFT SIDE ONLY or FOR RIGHT SIDE ONLY. They are not marked in any such way.