Tire Cupping

[onechaddude]

Originally Posted by kketterling

I would also check the shocks if they are Monroes you are right at the milage they usually need to be replaced. Replaced mine just before the new tires were installed and they were shot.

I did the same. Replaced Monroe's right after tires at about 15,000, and completely shot. Also noticed pretty much every coach I have seen with goodyears had riveting.
Chad

[JohnBoyToo]

Bad or under performing shocks (for the tire weight) allow the tires to go up and down as tejay said and basically they get into slight harmonics and will wear the same area over and over.... eventually making it such that you feel it....

[Triker56]

OP tires are cupping on the outside edge.
Good Year famous rivering is same ware on both outside edges. Not just on one side.
And rivierng is not cupping.

OP has another problem. Not the Good Year rivering.
All 6 of my 8 year 7 month old G670's have rivering. But it causes no problem in steering, balance etc.

[TeJay]

I may be incorrect on this but I believe that rivering and cupping are two different issues. I have seen cupping and pictures of rivering and they are different.

I'm still not convinced that a tire manufacturer as large as GY would have a problem "Rivering" and I guess "Cupping" as well that they wouldn't address and or correct.

TeJay

[Arch Hoagland]

Kaltire - Tire Wear Conditions

That is a pretty good link to explain what's going on.

[TeJay]

Thanks,
That a very good description for tire wear problems. I did some searching but never came up with that web sight. Thanks again.

As I said earlier, there are many, many factors and combinations of factors that contribute to tire wear. I'm still not convinced that a manufacturer of some tires is the reason for some tire wear patterns.

There may be some manufacturing design items like, tread design, rubber compound, sidewall construction etc that may accelerate some types of wear but the fact still remains that something on the vehicle out of specs (alignment, bearings, steering or suspension components, tire pressures, shocks, etc, etc) caused the wear and not the actual design of the tire.
Really and truly correct the problem and the abnormal tire wear won't happen again.
TeJay

[Buford B]

I had 19K on my Goodyears and they were rivering. Through persistance Goodyear prorated them, gave me 80% of new. Replaced them with Michelins and problem went away. Had everything on the front end checked at the time and found no issues.

[kketterling]

Buford B: How old were your tires when they prorated 80%? I probably should have tired to get something on my Goodyears but they were about 5 years old so didn't try, in hind sight might have been worth a shot just knew I didn't want to go back to Goodyears.

[onechaddude]

Originally Posted by kketterling

Buford B: How old were your tires when they prorated 80%? I probably should have tired to get something on my Goodyears but they were about 5 years old so didn't try, in hind sight might have been worth a shot just knew I didn't want to go back to Goodyears.

I'm with you except mine were almost 6 years old but had 15,000 miles. Also, I did not want goodyears either. I had coach aligned when new michelins were installed and tech said it was dead on. I figured must be goodyears and not alignment.
Chad

[Quicktree]

Originally Posted by TeJay

A simple answer is this. Cupping is usually the result of the tire not staying on the ground with the same pressure. Shocks dampen tire up and down movement from road changes. If the shocks don't absorb that energy the tires continue to oscillate. So weakened shocks won't keep the tire in as close a contact as good shocks. That is the primary cause of cupped tires.

Incorrect toe will cause a feather edge pattern on both front tires. Since the steer tires will tend to toe out when weight is placed on them the industry standard is 1/16" of toe in (the front of the tire is 1/16" closer than the rear).

Incorrect camber + or - will cause either inner or outer edge wear.
Caster misalignmentis not usually indicated by any tire wear patterns.

So you are back to shocks as your main cause but tire inflation pressures also enter into the picture. It is still recommended by ALL tire manufacturers to inflate your tires based on the weight that they carry and not the MAXIMUM PRESSURE indicated on the tire sidewall.

I would never blame a tire or a tire manufacturer as the cause of cupping. I've read to much about tires. Yes some tires will cup faster than others due to design issues, quality of rubber (cheaper tires), where it is driven, etc. But there is still a cause or reason why the tire cupped and that can be corrected.

TeJay

this is correct, cupping is a shock issue plain and simple.

[1bigguy2]

I had this issue. Alignment fixed it. 2 sets of tires later, it has not recurred.

Good luck

[Buford B]

My tires were 3 yrs old. The local Goodyear store claimed they'd never seen it before. (BS) I had the front end checked and installed Michelins. There was nothing wrong with the front end except it had Goodyear Tires on it. Got in touch with the area Goodyear Rep. it took awhile but eventually they gave me a check for 80% of new tires based on 100k life expectancy for their tires. Not to say it was easy but it was painless.

[lakewoodpaul]

Originally Posted by H. Miller

For some reason it's called "rivering"... Google that on iRV2 and get ready to read for hours.

Had the same problem 52k mi. Michellin tires took the rig to a reliable shop and was told this is a common occurence on high profile motorhomes. The tech told me he could sell me an allignment but it would be a waste of money. The clincher was the tech. document from Michellin he showed me that stated there was no fix. keep driving. there were pics on the document that looked exactly like mine Maybe the ops cupping was different from mine. anyway the issue exists on Goodyear tires also.

[Yogi-2]

My God – if I got 25000 out of the steer tire I would have been bankrupt long time ego. In RV’s – time and not miles should dictate tire change. @TeJay – you nail it – I would only add: if someone has only one tire cupping than it is the opposite side shock absorber. Just to be on the safe side I would check front bearing while on it.