Rotating tires -- Procomp directional treads

You follow the book rotation for the CJ7 or for bias ply tires and keep them on one side.

The spare goes to the right rear, which is the main wear or drive tire, the RR goes to the RF and the RF goes to the spare. The left side tires just swap back and front.

This will make for even wear over the life ot the tires.

Mike

86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00 88 Cherokee 235 BFG AT's

Steve wrote:

this also applies to radials as that is how the shop just rotated my timberline m/t's each side stays on their side just like mike said.

Well, 'you' know this, 'I' know this, my Jeeps owners manuals knows this, but there are a 'whole' pile of people here that think defective tires are 'normal' and cross rotate anyway like the tire makers recommend and get quite upset about hearing different.

It is safer to say to 'follow the CJ7 'book' pattern for radials' or any book pattern for bias ply... They don't own a CJ7 so don't get quite as offended. LOL!

Mike

wraithyjeep wrote:

That doesn't apply to standard radials, and hasn't in many years, only unidirectional radials like the ProComp XTerrain being asked about.

Jerry

wraithyjeep wrote:

I know that auto and tire manufactures all agree that cross rotation of radial tires (except uni-directional tires) is the desired rotation method.

What I'd like to know is why radial tires, when they were first made popular, were restricted to same side rotation. I mean physically, what was it that forced this deviation from the standard?

Second, what have they done to the design of radial tires that now allows cross rotation?

Third, have these changes only made cross rotation possible, but not necessarily good for the tires? That is, aside from uneven wear, which is rotation method is actually better for the tire?

I'm pulling these numbers out of thin air, but they illustrate my question.

Original radial tires:

Cross rotation has 10 failures in 1,000,000 miles Same side has 5 failures in 1,000,000 miles

Newer radial tires:

Cross rotation has 5 failures in 1,000,000 miles Same side has 2 failures in 1,000,000 miles

Does anybody know the actual failure rate?

-- msosborn at msosborn dot com

Matt, one of the major tire manufacturers... it had to have been BFG, Goodyear, or similar actually answered that question years ago. They explained that the first radial tires were manufacturerd on the same equipment used to make bias-belted tires which causes problems. What problems, I don't know.... other than you couldn't cross-rotate them. Then they came out with different manufacturing equipment that was specifically designed for radial tires that solved the issues with the first generation tires. I read it with my own two eyes, it wasn't my friend's cousin's brother-in-law that related that to me. :)

Jerry

Matt Osborn wrote:

It is my understanding the differences from the first gen radials was in their construction and how the radial belts were made into the tire compaired to todays construction new gen radials. I think it all had to do with the belts and which direction they were wound but do not quite me I am going from memory.

Coasty

Remove the SPOOGE to reply

Rotate from front to back, and leave the spare on the rack. Don't make this harder than it needs to be.

PS The IN side of the tire is always toward the Jeep, but the tires turn one way (CCW) on the left side, and the other way (CW) on the right side.

The whole question leaves me in doubt. Obviously, the tire manufacturers 'thought' they were making the tires correctly and then discovered the radial belt separation problem.

They then redesigned the manufacturing process to sufficiently overcome the problem. It is the lack of specific information that leaves the question unsettled.

It is not at all difficult for me to believe that the radial belts will take a 'set ' based on the direction of rotation due to centripetal forces. Reversing the rotation will must counter that initial set of the radial belts. I can't see how that will improve the safety of the tire.

I guess I'm just being stubborn, but I will trade the slight wear differences in favor of safety.

-- msosborn at msosborn dot com

OK.....these are mud tires....so I expect more wear than on a standard tire. So, if I don't rotate in teh spare.....30,000km down the road when I've worn Xinches off my tires and I go to put on my spare which still has the little bristles things on it.....will i not stress gearage and bearings by having one tire large than another on the same axle?

Ok....but what's the point of having a spare.....to throw on when you have an unrepairable flat.

Actually, now that I think (it happens)....my spare can't just go on either side as it's a directional tread too. haha....

So is there an issue with running your tread backwards...as in the spare...so temporarily?!

You need two spares or you should have done what most folks with directional tires do and just get a 'real' spare. That means getting a tire as tall as your street tires and as skinny as you can find to cut down on weight and use that as a spare.

That 5th tire is now just dead weight.

Mike

86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00 88 Cherokee 235 BFG AT's

Steve wrote:

Back when I started driving OEM bias ply tires were only good for 12k miles and you would do a 5 tire rotation for that first year and buy 4 new tires of better quality that would last 16-20k and keep the best of the original tires as the spare.

When winter arrived you would buy 2 studded snow tires and 1 used steel rim and have them mounted for the winter season on your spare and that used rim.

When summer arrived you would dismount the snows and put one in your garage and one in the trunk as your spare.

From then on you did a 4 tire rotation. Things progressed over the next few years first with belted bias-ply tires that would last 24-30K miles and then steel belted radials that lasted 30-40k.

My first radials in 1974 was a set of Kelly's that had 4 body plys and 3 steel belts. The ride was punishing but the handling was phenomenal

As has been mentioned before the early radials were rotated front to back. I don't recall ever asking why but just followed their instructions.

For a few years there were a variety of radial construction ideas. Steel, polyester, nylon, rayon, fiberglass, aramid, and even Kevlar was used in the radial's construction.

I don't know when the rotation changed back again to one of the cross rotation methods but I am guessing about 15 years ago as I am fairly sure the OEM Vectors that came on my '84 Dodge Aries were still rotated front-back.

After that I had 2 T-Birds, an XJ, and 2 Audis. The T-Birds and Audis had direction performance tires and has to be rotated front-back which had been my practice for many years. I bought the XJ while I still had the 2nd T'Bird so I rotated the OEM Wranglers in the same manner.

What does this have to do with ProComp you say.... If the ProComps are directional they will say so on the sidewall. If by any other quirk in their construction they require a specific rotational method the manufacturer will advise you. They may not have an incentive to maximize your tires longevity but in this modern litigious society they absolutely WILL NOT advise you to do anything that would lead to early catastrophic failure as shyster lawyers would have them in court until they drove ProComp into bankruptcy with both real and fraudulent claims.

For what it is worth my WJ's manual and the factory manual (on CD) recommend forward-cross back rotation. on section 22 page 5 STANDARD PROCEDURE - TIRE ROTATION

Tires on the front and rear operate at different

loads and perform different steering, driving, and

braking functions. For these reasons they wear at

unequal rates and tend to develop irregular wear

patterns. These effects can be reduced by rotating

the tires at regular intervals. The benefits of tire

rotation are:

² Increase tread life ² Maintain traction levels ² A smooth, quiet ride

The suggested method of tire rotation is (Fig. 10).

Other rotation methods can be used, but they will

not provide all the tire longevity benefits.

(Figure 10 shows four tire rotation with the rear tires to the front on the same side and then the front tires crossed and mounted on the rear)

My Conclusion: Your spare is a spare, it is just meant to last until you are able to get the flat tire fixed or replaced. I have a brand new OEM Wrangler ST as a spare and it is going to stay there. When I bought the WJ a part of the deal was a replacement of the tires with ones of GOOD quality. I got a set of 4 highly rated Kumhos for an additional $125 to replace the Wranglers

I do not rotate my tires on my Jeep. They tend to wear out pretty evenly, although I'll be the first to admit the wear pattern on each tire is different. I have stumbled into a problem, I have a brand spanking new BFG Mud Terrain, 32x11.50 that is no longer available. When I buy new tires, the MT is now the MT/KM and has a different tread pattern.

Yes, you may have stress issues, but I suggest that you stress the diffs much more while wheeling than you'll ever stress them from having a new tire on one side and an old tire on the other. Drive home on the new tire and visit the tire store to get the old tire repaired or replaced, and hang the new tire back on the rack, or put the two new tires on the back, the best of the old tires on the front, and the best remaining old tire on the rack, and go wheeling again.

Me thinks you're confused.

You do not have directional tires, you have tires that have an inside and an outside, and they must be mounted on the rim the right way, but they can be used on either side of your Jeep. If they have an arrow that indicates that the tire must turn "this way", then they are directional, but if they simply say "outside", they are not directional.

I have tires on my BMW that say, "outside", but they can be swapped from side to side because the outside remains on the outside as long as the tire is on the rim right. A Directional Tire has a Rotation Direction indicator molded on it, and a spare with a direction wouldn't be very useful if it was for a left hand rotation, and it was needed in a right hand application.