Reply
 
Thread Tools Display Modes
Old 09-17-2015, 10:12 AM   #51
Senior Member
 
Join Date: Nov 2014
Posts: 147
In some sizes it's very hard to come up with higher load range trailer tires from a decent vendor. I shopped extensively for 205/75R14 load range D and Kumho was the only acceptable vendor. I avoided truck tires because of advice I found that they're not appropriate for trailering.
__________________

__________________
Gyrogearloose is offline   Reply With Quote
Old 09-17-2015, 12:03 PM   #52
Commercial Member
 
Join Date: Jul 2013
Location: Akron, Ohio
Posts: 1,145
Kenz
have you filed a complaint with NHTSA?

No complaints mean no investigation which means fo possibility of there being a recall.
With no recalls tire companies get the message that poor tire quality has no downside.
__________________

__________________
.
I write a blog on RV tire application and safety and give seminars on tires at RV events across the US. 40 years experience as tire design & quality engineer for major tire mfg. Freelander 23QB on Chevy chassis is my RV
RV Tire Safety Blog
Tireman9 is offline   Reply With Quote
Old 09-17-2015, 12:06 PM   #53
Commercial Member
 
Join Date: Jul 2013
Location: Akron, Ohio
Posts: 1,145
IMO
Tires without a speed rating are more likely to fail than those without in current normal RV service.

Also No or short Warranty indicates to me that a manufacturer has no confidence in the product they are selling.
__________________
.
I write a blog on RV tire application and safety and give seminars on tires at RV events across the US. 40 years experience as tire design & quality engineer for major tire mfg. Freelander 23QB on Chevy chassis is my RV
RV Tire Safety Blog
Tireman9 is offline   Reply With Quote
Old 09-17-2015, 05:08 PM   #54
Senior Member
 
Kenz's Avatar
 
Join Date: Apr 2014
Location: Michigan
Posts: 134
I didn't report it, actually didn't think about it. Don't have the tire any more but still have the pics. Think I'll go to the website and do that.
As for the debate over ST vs LT tires that would fill pages, but ST tires are fairly new in the larger 16" sizes. My 2000 36' Prospera came new with Goodyear Wrangler LT tires. I've read alot about ST tires and the idea and design makes perfect sense. But the quality of manufacture is terrible. My 2011 came with ST 235 80 16 and I swapped for a LT 235 85 16 a size difference of about 1" diameter.
When it comes to who puts these things on new trailers, i believe it's a case of looking the other way. The majority of manufacturers buy there frames from a vendor like Lippert. Tires are already on when delivered. They use the cheapest possible and the manufacturer just looks the other way. And yes they can can demand what goes on the frame, but I believe because of cost it's a don't ask, don't tell kind of thing.
__________________
2011 Coachmen North Ridge 290RKD 5'er
2005 Dodge quad cab dually diesel 6'spd manual
1 weird cat with an occasional attitude problem.
Kenz is offline   Reply With Quote
Old 10-07-2015, 04:15 PM   #55
Senior Member
 
Join Date: Nov 2014
Posts: 147
I did an interesting calculation this morning.
It dawned on me that on turns, weight gets transferred to the outside wheels of my trailer.
So I asked myself how much increased load do my tires see on turns.
This calculation is simplified by the discovery of the criterion used by civil engineers to set advisory speeds on curves: a ball bank indicator should show no more than 10 degrees at the advised speed (on a yellow speed limit sign).


Presuming my math is right, the bottom line is that each of my two outside tires will see an increased load of about 350lbs during a curve taken at advised speed in my 7500lb trailer.
The factory tires on my trailer have a 1760lb load rating and are pushed to the limit by Forest River, so 350lbs is about 20% over the tire rating.
It seems to me that this needs to be added to the trailer static load on the tires when calculating tire load rating, and it adds credibility to the 20% margin recommended by Carlisle Tire.
FR clearly ignores this.
__________________
Gyrogearloose is offline   Reply With Quote
Old 10-10-2015, 02:49 PM   #56
Senior Member
 
Airdale's Avatar
 
Join Date: Jul 2013
Posts: 734
Quote:
Originally Posted by Gyrogearloose View Post

The factory tires on my trailer have a 1760lb load rating and are pushed to the limit by Forest River, so 350lbs is about 20% over the tire rating.
It seems to me that this needs to be added to the trailer static load on the tires when calculating tire load rating, and it adds credibility to the 20% margin recommended by Carlisle Tire.
FR clearly ignores this.
Carlisle is not tasked with tire to vehicle fitments. A weight recommendation for reserve load capacity is in no way binding on the vehicle manufacturer's fitments. The only weight restriction binding to both the tire and vehicle manufacturer is the published maximum load capacity of the tire that is clearly certified on the tire's sidewall.

If there is a fallacy in tire fitments for RV trailer axles it belongs to the regulating authority that allows manufacturers of those vehicles to use tires that match the GAWR loads.
__________________
Airdale is offline   Reply With Quote
Old 10-10-2015, 04:50 PM   #57
Senior Member
 
Join Date: Nov 2014
Posts: 147
Quote:
Originally Posted by Airdale View Post
Carlisle is not tasked with tire to vehicle fitments. A weight recommendation for reserve load capacity is in no way binding on the vehicle manufacturer's fitments. The only weight restriction binding to both the tire and vehicle manufacturer is the published maximum load capacity of the tire that is clearly certified on the tire's sidewall.

If there is a fallacy in tire fitments for RV trailer axles it belongs to the regulating authority that allows manufacturers of those vehicles to use tires that match the GAWR loads.
The problem I'm pointing at is that there is no margin in some Forest River products between the tire load rating and the estimated applied load. The absence of a margin means that individual tires can be over loaded for a host of possible reasons like production differences in axle force constants, or like additional loading as weight shifts on curves.

That Forest River can get away with doing this may indeed be a flaw in government supervision. The NHTSA is overworked and probably misses a bunch of problems as a result. This shouldn't change the ethics of selling a product that is potentially unsafe.

As a consumer who purchased a Forest River product, my focus is on my trailer and its manufacturer. I believe that my trailer will overload the tires due to weight transfer to the outside wheels when I am driving reasonably on a winding road. As a consumer, I view this as a product defect and safety issue, irrespective of whether the governmental agencies have noticed it.

And, it occurs to me that if Forest River is aware that tires can be overloaded when their products are otherwise being used in a reasonable manner, and if someone ends up seriously injured or killed as a result, this is likely to result in significant liability to FR irrespective of governmental supervision.
__________________
Gyrogearloose is offline   Reply With Quote
Old 10-10-2015, 07:53 PM   #58
Senior Member
 
Airdale's Avatar
 
Join Date: Jul 2013
Posts: 734
Quote:
Originally Posted by Gyrogearloose View Post
The problem I'm pointing at is that there is no margin in some Forest River products between the tire load rating and the estimated applied load. The absence of a margin means that individual tires can be over loaded for a host of possible reasons like production differences in axle force constants, or like additional loading as weight shifts on curves.

That Forest River can get away with doing this may indeed be a flaw in government supervision. The NHTSA is overworked and probably misses a bunch of problems as a result. This shouldn't change the ethics of selling a product that is potentially unsafe.

As a consumer who purchased a Forest River product, my focus is on my trailer and its manufacturer. I believe that my trailer will overload the tires due to weight transfer to the outside wheels when I am driving reasonably on a winding road. As a consumer, I view this as a product defect and safety issue, irrespective of whether the governmental agencies have noticed it.

And, it occurs to me that if Forest River is aware that tires can be overloaded when their products are otherwise being used in a reasonable manner, and if someone ends up seriously injured or killed as a result, this is likely to result in significant liability to FR irrespective of governmental supervision.
Flawed rules are the same for all RV trailer manufacturers. I doubt that FR can be held responsible for following the rules as they are presented to them. To do so would severely impact their ability to compete with other like RV trailer manufactures.

These are out of context quotes from one of the tire safety regulations.

1. The sum of the maximum load ratings of the tires fitted to an axle shall be not less than the gross axle weight rating (GAWR) of the axle system as specified on the vehicle's certification label.

2. The size designation and the recommended cold inflation pressure for those tires such that the sum of the load ratings of the tires on each axle is appropriate.

3. The size designation and, if applicable, the type designation of Rims are appropriate for those tires.

4. On RV trailers, the sum of the GAWRs of all axles on the vehicle plus the vehicle manufacturer's recommended tongue weight must not be less than the GVWR. If tongue weight is specified as a range, the minimum value must be used.

5. The UVW and the GVWR used to determine the RV's load carrying capacity must reflect the weights and design of the motor home or RV trailer as configured for delivery to the dealer/service facility. If applicable, the weight of full propane tanks must be included in the RV's UVW and the weight of on-board potable water must be treated as cargo.

Other safety regulations govern equipment testing resulting in certification. Tire certification testing is normally done by a third party but can also be done by the individual manufacturer or at a NHTSA testing facility. Not all tires in a batch/lot are tested. It’s a random procedure except in a recall situation unless the cause for the recall is known.

The nitty-gritty: Regulations for Automotive tires provide reserve load capacities beyond a vehicle’s GVWR. In the same regulation RV trailer tires are not required to provide any load capacity beyond GAWR. It was hashed over in the last round of the rules making process but no action was taken.

Morally (IMO) its wrong for a RV trailer manufacturer to put two 3000# tires on a certified 6000# axle. Its been done and will continue to be done as long as the current regulations remain unchanged.

Usage safety regulations are written for an end item such as a tire. Engineering of that tire is what got it on the market in the first place.
__________________
Airdale is offline   Reply With Quote
Old 10-10-2015, 09:08 PM   #59
Senior Member
 
Join Date: Nov 2014
Posts: 147
Quote:
Originally Posted by Airdale View Post
Flawed rules are the same for all RV trailer manufacturers. I doubt that FR can be held responsible for following the rules as they are presented to them. To do so would severely impact their ability to compete with other like RV trailer manufactures.
I agree that the playing field must ultimately be level for all manufacturers of a product. However, this is not an excuse to ship a defective product.

I don't doubt that current regulations don't take into account weight transfer during curves, or any of the other many possible scenarios that would push individual tires above their ratings on a marginally designed vehicle. This is an example of how we all lose when government watchdogs are inadequately funded and staffed. I'm not arguing that Forest River isn't meeting government regulations.

I had an unexplained tire failure on a winding mountain road that could easily have turned into a disaster. There's a good likelihood that this was directly related to driving repeated curves and the resulting increased load and stress on the outside tires. Based on my math, my tires could have been overloaded on curves by the trailer design and choice of marginal tires.

As I've looked into it, I'm not the only one who has had a similar experience. There's a pattern visible in discussion groups of tire failure on RVs that you just don't see for other vehicles. Something is broken here, and it's not that we're all abusing our tires.

I think the likelihood of overloading of tires on trailers that have no load margin is a real issue. If Forest River is aware that normal use of their product could lead to tire failure and resulting injury or death, then they have a moral, ethical, and I think legal obligation to take action to correct the problem. (Think what would have happened if Takata had known of the risk associated with its airbags, which no doubt passed current regulations at the time, and ignored it.)

Forest River is now aware of this problem at the lower echelons because I've been noisy with them about it and have written records of the interactions. I will make sure that they're also aware of it at the top of the organization. If they fail to act on it, and if I am correct about the potential for overloading of tires, then they do so at their peril. When someone eventually gets hurt by a tire failure like mine, product liability lawyers will be circling around them.
__________________
Gyrogearloose is offline   Reply With Quote
Old 10-10-2015, 10:23 PM   #60
Senior Member
 
Join Date: Nov 2014
Posts: 147
Quote:
Originally Posted by Airdale View Post
Flawed rules are the same for all RV trailer manufacturers. I doubt that FR can be held responsible for following the rules as they are presented to them.
This raised my curiosity about liability law.
Liability laws are apparently written at the state, and not federal, level.
I found the following words in the first state statute that I examined.
This is the state of Texas.
"The claimant may rebut...by establishing that...the mandatory federal safety standards or regulations applicable to the product were inadequate to protect the public from unreasonable risks of injury or damage..."

In other words, if government standards apply and were followed, a manufacturer can still be held liable for injury if it can be shown that the standards were inadequate. In the current case, I don't think this would be very hard to do.

It would seem, therefore, that Forest River can still be held accountable for overloading of tires due to weight transfer on curves even though FR was compliant with the government rules.
__________________

__________________
Gyrogearloose is offline   Reply With Quote
Reply

Tags
tire, tires

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



» Virginia Campgrounds

Reviews provided by




ForestRiverForums.com is not in any way associated with Forest River, Inc. or its associated RV manufacturing divisions.


Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -5. The time now is 04:37 AM.