Carlisle tread diagnosis

[crispyboy]

I opened my email tonight and I had already received a response from Carlisle.

Good afternoon, Mr. Broering:

I have been authorized to send replacement tires. I will be shipping 4 ST225/75R15-D RTrl RH tires to you. These tires are a new product, I have been advised, that are more heat resistant and more accepting of the challenges of long road travel.

I will place the order tomorrow morning for shipment to be released on 8/19.

I will send you a confirmation email advising of the estimated delivery date.

Thank you,


I truly wasn't expecting anything from Carlisle as I called them just to discuss these tires. Maybe I should purchase a lottery ticket tomorrow!
It's funny how simple things in life can make you happy - the wife and I danced around the kitchen table with the news on the tires.

Capri-
I hope you will still address a few of the above questions as I have a feeling I will be going through this exercise again in 3 years.

[jcanavera]

Originally Posted by crispyboy

I opened my email tonight and I had already received a response from Carlisle.

Good afternoon, Mr. Broering:

I have been authorized to send replacement tires. I will be shipping 4 ST225/75R15-D RTrl RH tires to you. These tires are a new product, I have been advised, that are more heat resistant and more accepting of the challenges of long road travel.

I will place the order tomorrow morning for shipment to be released on 8/19.

I will send you a confirmation email advising of the estimated delivery date.

Thank you,
.

Interesting that there are two comments that say a lot to me. "More heat resistant" and "more accepting of the challenges of long road travel". It says a lot to why many of us are forgoing ST tires for LT's.

I'm glad these folks are stepping up to the plate but it just confirms maybe that these tires as a class, are missing the mark.

Jack

[SteveSueMac]

Originally Posted by jcanavera

I'm glad these folks are stepping up to the plate but it just confirms maybe that these tires as a class, are missing the mark.

Jack

Maybe (hopefully? ) manufacturers are addressing the challenges with STs and making them better?

I dunno....I jumped on the LT wagon too :-/

Congrats on the new set of tires, Crispy!! :-)
Nice surprise since you said they were a year out of warranty. Happy trails!!

[richinny]

hey crispy, i hope you have a BIG mailbox! keep us posted on the performance of the new tires.

[CapriRacer]

Originally Posted by crispyboy

Capri,
Thanks for the analysis but I have a couple of questions.

OK, doing the math:

Trailer load on tires: 7360# Correct

Average load on each tire: 1840# Correct

Accounting for side to side and front to rear load variation: max load 2116#. I understand the concept of load variation factor but how do you come up with 2116#?........

I added 15%. I only have a limited amount of data to support this, but this value seems to be a bit high, but within reason.

.........Adding 15% over capacity: 2433#. This figure seems to be load variation plus 15%. Is this a typical engineering safety factor for all tires or ST tires?

No, this is a 15% over-capacity. I think it makes good engineering sense
to over-specify. Other apparently do too, as I note that most major vehicle manufacturers increased tire sizing shortly after the Ford/Firestone thing a few years back.

Note: They also increased the speed rating specified.

............So I think your Load Range D tires are OK from that perspective.

But I also think trailer tire ought to be loaded such that they aren't speed restricted to 65 mph. That makes the load 2974#. Yes there are times when more speed is needed but no more than 70. If I installed load range E ST tires could I run up to 70 mph since the rating is much higher than actually needed?...........

Yes, but if you want 85 mph, you'll need to go to the 16"

.........But I think you need to moving up to a Load Range E or moving up to a 16". This puts the nail in the coffin for the Michelin XL 15" tire....

Which is why I did that.

......And is that a plug in the bottom photo? That might be the cause of the tire failure? There are no plugs, I drive around curbs, not over them and the tires have been great until now - never loose air but do get warm on the highway.

PLUS: Is the bulge in one spot or 360° around the tire. If 360°, it's probably not a separation. The bulge is in one spot.....

Then that is likely a separation.

.......Yesterday on a lark I called Carlisle tire customer service to ask them about what I have found on the tire. They put me through to the warranty department and opened a claim form. They were interested in my story and requested many pictures of what I found and will forward them onto their engineer. I'll let you know of the response I get. I'm really not expecting much from the phone call since the tires are one year out of warranty but I've got my fingers crossed they may throw me a bone.

2 thoughts:

1) Did you file a report with NHTSA? The only way the Federal Government is going to get involved is if there are plenty of reports.

2) Did Carlisle ask to see the tire? Without examining the tire, then sending you a replacement set is just a goodwill gesture.

[NJtoNC]

I had a blowout on carliles too. Also 225 75's ST's. my blowout was in 2012. Leas than 10k. On my globetrotter! Well under rating. I had need going 45 mph and just left home 30 minutes prior.

The tires were new in 2010. Installed in summer 2010. Tire blew sept 2012 just out of warranty. Will never buy carliles again. I'm running Michelin LTX 235 75 15 LTs now.

[pappy19]

I would take those new ST's and trade them in on new 16" Michelin LT's, easy credit.

Pap

[airdreamers]

Originally Posted by crispyboy

I opened my email tonight and I had already received a response from Carlisle.

Good afternoon, Mr. Broering:

I have been authorized to send replacement tires. I will be shipping 4 ST225/75R15-D RTrl RH tires to you. These tires are a new product, I have been advised, that are more heat resistant and more accepting of the challenges of long road travel.

I will place the order tomorrow morning for shipment to be released on 8/19.

I will send you a confirmation email advising of the estimated delivery date.

Thank you,


I truly wasn't expecting anything from Carlisle as I called them just to discuss these tires. Maybe I should purchase a lottery ticket tomorrow!
It's funny how simple things in life can make you happy - the wife and I danced around the kitchen table with the news on the tires.

Capri-
I hope you will still address a few of the above questions as I have a feeling I will be going through this exercise again in 3 years.

I wasn't sure it you were going to respond to my post but I guess you did contact Carlisle after all. I glad it worked out for you!

[crispyboy]

Originally Posted by jcanavera

I'm glad these folks are stepping up to the plate but it just confirms maybe that these tires as a class, are missing the mark.

Jack

I totally agree with this statement. I was reading Carlisle "tips and best practices" (page 3, left column, 8th bullet point) on their website and one statement that reveals a lot is "It is estimated that in approximately three years, roughly one-third of a tire's strength is gone". I assume this statement is meant for ST tires as P and LT seem to degrade at a slower rate.

Originally Posted by CapriRacer

2 thoughts:

1) Did you file a report with NHTSA? The only way the Federal Government is going to get involved is if there are plenty of reports.

2) Did Carlisle ask to see the tire? Without examining the tire, then sending you a replacement set is just a goodwill gesture.

I have not filed a report and I need to look into this.
Carlisle has not asked to see the tire. They seemed to be satisfied with the detailed pictures and description I sent.
BTW - thanks for explaining your analysis. I am looking at tires in a whole new light now. Others will benefit too from reading this.

Originally Posted by pappy19

I would take those new ST's and trade them in on new 16" Michelin LT's, easy credit.

Pap

An interesting thought and I guess I could justify it as preventative maintenance. I wonder how quick they would sell on craigslist...

[switz]

When I was pushing weight numbers to use the Michelin LTX (P) 235/75R15 XL tires on my 25FB International (GVW 7,300 pounds), I came up with with a decent safety margin for me. I knew my loaded tongue weight at my reference weighing point was 1,175 pounds which I rounded up to 1,200 for easier mental math. Deducting the tongue weight from the GVW left 6,100 pounds. I used the commonly referenced 1/3 weight transfer to the trailer from the weight distribution hitch which brought the axle load to about 6,500 pounds. The four Michelin's derated capacity is 7,940 pounds or about a 22% margin.

The 27FB International has a GVW of 7,600 pounds and using the 1,200 pound tongue weight as above, the axle load would now be closer to 6,800 pounds or just under a 15% margin. That would be snug for my comfort factor.

But we opted for the 27FB Classic with twin beds with a 9,000 pound GVW. No matter how I massage the numbers, the 15" Michelins would be at or above their derated capacity. Thus, I went for the same SenDel 16" wheels and Michelin LT 225/75R16E tires the Airstream factory installs on the Eddie Bauer trailers and offers to install at their store at the factory. And I ended with about a 22% margin.

One needs to get actual scale numbers to accurately assess the true weights associated with their specific trailer before conducting specific tire selection.

Our new trailer comes in at the end of January or first week of February. After I swap the 16" tires and wheels for the OEM tires and wheels, I will pay a tire shop to remove and dispose of the original GYM tires and then I will sell the four aluminum and one steel 15" wheels.

[Tireman9]

RE tire separations. Be sure to read post #40 on this thread and watch the video.

[ROBERT CROSS]

Originally Posted by Tireman9

RE tire separations. Be sure to read post #40 on this thread and watch the video.

TM9,

Thank's for your input on this thread....good info.



BTW...if you click on the post # you can link the post instead of the entire thread.

Bob

[Tireman9]

Couple of general comments in no particular order.

People complain about "bad tires" being on the road but very few ever make the effort to file an actionable, complete and accurate report with NHTSA. I have written NUMBER of times on the failure of RV owners to properly file a complaint. If you read my blog posts and still have questions PM me and I will help walk you through the process.

I fully support CapriRacer's 15% "safety factor" for tire load. You may not realize it but many car manufacturers use a factor in this range.

I do NOT support adjustments to allow ST tires to run faster than 65 mph. I consider this much like an engine Red Line. If you think it OK to exceed the red line of your engine but expect the same life I think you are fooling yourself. I have a post just on the topic of "Engine Blowouts". I am only aware of one company that is willing to put in writing the steps needed to exceed 65. It is absolutely wrong to apply one companie's policy to tires manufactured by other companies, especially when we are talking about going outside the normal range of load, speed, inflation. If you have Goodyear tires you should not use Michelin Load/Inflation charts etc.

I understand the idea of air leaking to between the belts & tread being the cause of separations but in reality separations come from "interply shear" and the degradation of the rubber properties and strength due to excess heat. Heat comes from High Load, Low Inflation and High speed and Sun Exposure, All of which are in the control of the owner when operating or in the case of Sun when parking and a cover is used or not.

[Tireman9]

If you read the post #40 and watched the video you can see the results of the actual cut tire autopsy in the post of Dec 24 2012 "Why don't RV tires get recalled?"on my blog.

[crispyboy]

I received 4 new tires on August 19 from Carlisle as promised.
I went ahead and filed out an on-line complaint form with the NHTSA. It was a 10 minute process (relatively painless) once I had the info off of the old tire.
Both the old and new tires were manufactured at Meiyan Tire CO., LTD, Meixian, Guangdong, China.
I still have a queasy feeling in my gut about installing the new ones but it is hard to pass up a freebie.

[switz]

Your cost for the free Chinese tires will be the deductible on your trailer insurance and all the non reimbursable expenses incurred when the tires fail, not if they will fail.

[CapriRacer]

Crispy,

First, thanks for filing that report.

Second, I think everyone would agree that even those ST tires that are known to have issues are good for a couple of years.

And, third, Carlisle never asked for the old tires back, right? Shame on them.

[crispyboy]

Correct. Carlisle never asked for the old tires back, clearly a "goodwill public relations" gesture.
I took the tires to get mounted and balanced and the technician could see the tires were separating from several feet away. He took a piece of chalk and wrote "SEP" on them so nobody took them home. The old tires had worn very evenly.