Is this a directional tire........

[SLX5]

I feel pretty stupid asking this question


Continental CrossContact UHP


look at the picture in the middle. Based on the thread pattern it looks like a directional tire. But if you mount it like that it would look wired from the back, in other words the tire on the rear left and right would look like the picture in the center. Like I said feel pretty stupid asking the question, but thought I would check with some knowledgeable people.

[Weasel]

That is an asymmetrical tire, meaning it has an "inside" and "outside". Doesn't matter what side it is on as long as the tire is mounted on the rim properly.

[SLX5]

Weasel, thanks for the post. I am truely amazed at your wealth of knowledge and how many people you help out. Whenever I browse through a thread i always make sure i read your comments.
Thankx

[taosx5]

Weasel,
I have seen many wise statments from you, thanks for all the great advice. Another stupid question! Since a tire like the Diamaris are asymetrical, and they do not come in a left or right, so long as they are mounted on the wheel correctly, what is the reason you cannot rotate? I think I knew this in my younger days but my brain has lost this info.

[FSETH]

Originally Posted by taosx5

Weasel,
I have seen many wise statments from you, thanks for all the great advice. Another stupid question! Since a tire like the Diamaris are asymetrical, and they do not come in a left or right, so long as they are mounted on the wheel correctly, what is the reason you cannot rotate? I think I knew this in my younger days but my brain has lost this info.

Technically, you CAN rotate them if they are the same size front and back, but due to camber setting and other issues BMW tires wear very differently in the front and the back. Rears tend to wear very quickly on the inside of the tire. Rotating those to the front will change how your tire makes contact with the road. I am pretty sure BMW does not recommend rotating tires for safety and handling reasons.

If you have staggered wheels, rotating isn't possible anyway without removing the tire from the rim. Even then you would only be going side to side and the tire would end up wearing in the same place anyway.

[Weasel]

FSETH pretty much nailed it, with the staggered asymmetrical tires you can only go left to right, and the tires wear individually due to camber and tow settings to the point that swapping them from side to side would actually accelerate wear and lower grip while they are being worn in to the mirrored specs of the other side... And they would be rolling backwards from how they are used to so there would be a possibility of the belts coming apart internally which would cause a shifted tread. (not that common with premium tires though, usually the cheap-o's)

And as always, glad to help!

[SLX5]

Weasel,
so with these tires I got (same size on all four), I should "NOT" rotate them ever? Just balance them every so often and keep them in the same location?

[Weasel]

That is the best way and BMW's recommendation. The tires wear to the angles they are held at by the suspension, and when you rotate them you are changing the angles they are held at... making them wear to the opposite angles pretty much.

[anerbe]

non-staggered asymmetrical can benefit from rotation according to 2wd or 4wd configurations. look up the diagrams online. if rears are wearing faster than fronts, you can swap the rears/fronts to get more life out of the tires. although angles at which the tires contact the road are different, they will eventually wear like the original configuration. even new OE tires you buy from BMW will have to go through the same wear changes anyways, and new tires typically are not considered "out of spec" or not advised. I feel if BMW does not push rotation schedules on non-staggered setups, it could be more of a money maker to buy new tires opposed to utilizing current tires.

staggered asymmetrical typically do not benefit from rotation, including swapping left/right, unless 1. your alignment is way off or 2. you always take one directional turns.

[JCL]

Originally Posted by anerbe

I feel if BMW does not push rotation schedules on non-staggered setups, it could be more of a money maker to buy new tires opposed to utilizing current tires.

I disagree. I went approximately 70,000 km on my X5 3.0 without rotating, the tires were not worn out, and they were wearing evenly. I would pay attention to the correct inflation pressures, and watch for uneven wear which could indicate an alignment issue. The vehicle is designed to have excellent handling, and rotating the tires will negatively impact that handling. I think that BMW's recommendation to not rotate is based on the reality that it is not required to the extent that it used to be, and they don't want to compromise the handling. It certainly isn't a plan to sell more tires, given that very few owners would ever go to the dealer to buy replacement tires.