TIRES?????

FastEagle wrote:

Me Again wrote:


Not completely true. The Cardinal Club via its forum and rallies has collected enough info and feed it back to Forest River/Cardinal to change the wheels they install and create an factory option for LRG tires. So spreading the word on forums like this does have value.

Chris

The LRG tire is the last item in their features/options brochures. But other fiver manufacturers such as NuWa and Keystone have equal options for their GAWR 6750# and above axles.

When more manufacturers come on-line with the ST235/85R16F rated at 3960# that option - because of the dollar value to the vehicle manufacturer - will be a standard option offered in trailer brochures for the heavier axles.


FR Specs

FE

You just never want to give up on tires restricted to 65 MPH and the lower testing standards! As long as we buy into these inflated ratings there will still be problems. Upping the inflation and making minor changes to the wrapper to handle the increase inflation and weight ratings, still leaves one on a tire type that is a compromise from the get go. And for existing people that have wheels rated for lower inflation and/or weight they still are faced with the purchase of wheels. This includes all those wheels rated to 3750. Where are the 16" wheels rated to LRF ST ratings? Which manufacturer is now using OEM LRF tires, I would like to figure out what wheel they are using?

Did I miss something? Is NuWa back in production?

Chris

Me Again wrote:


Not completely true. The Cardinal Club via its forum and rallies has collected enough info and feed it back to Forest River/Cardinal to change the wheels they install and create an factory option for LRG tires. So spreading the word on forums like this does have value.

Chris

The LRG tire is the last item in their features/options brochures. But other fiver manufacturers such as NuWa and Keystone have equal options for their GAWR 6750# and above axles.

When more manufacturers come on-line with the ST235/85R16F rated at 3960# that option - because of the dollar value to the vehicle manufacturer - will be a standard option offered in trailer brochures for the heavier axles.


FR Specs

FE

RVUSA wrote:

Me Again wrote:
Why are the manufacturers being allowed to install minimal tires?

Why? Because none of the adults on here and elsewhere have sued them for putting on deficient tires for the job. At some point one has to take responsibility for their outcome and do something about it.

Wailing endlessly on forums wont do anything but stir the pot.

Not completely true. The Cardinal Club via its forum and rallies has collected enough info and feed it back to Forest River/Cardinal to change the wheels they install and create an factory option for LRG tires. So spreading the word on forums like this does have value.

Chris

Me Again wrote:
Why are the manufacturers being allowed to install minimal tires?

Why? Because none of the adults on here and elsewhere have sued them for putting on deficient tires for the job. At some point one has to take responsibility for their outcome and do something about it.

Wailing endlessly on forums wont do anything but stir the pot.

CapriRacer wrote:
Word of caution:

The load on tires varies front to rear and side to side. If you are doing reserve capacity calculations you have to account for this. If you've weighed the trailer, tire by tire, then you know what the variation is.

But if you weighed your trailer axle by axle, I'd recommend to use a 10% figure for the worst case - and if you weighed your trailer as a whole (that is, not axle by axle, or tire by tire), then I'd recommend using 15%.

To put this in perspective, RVUSA quoted some figures, but didn't account for the variation - and at 12.7%, he just might have an overloaded tire. But we can't be sure without individual tire weights.

Everything you say is true, and there is a definite possibility that the rear axle, passenger side tire, is over loaded so to speak. The fridge sits above and slightly aft of that tire, and it is consistently the warmest tire.

I didn't go into the details of that portion of the loading and as you pointed out in your own follow up I should have just to make all sources of load balancing problems apparent so anyone following along wouldn't be misled in how to figure their own numbers.

The last thing that I want to do is to lead someone in the wrong direction when it comes to load balancing their tires.

Edit: I will add that I run the rear axle tires at 85 psi. and the front at 80 (the max psi on the sidewall). I bumped the rears up based on goodyears recommendation to minimize heat build up on their Marathons. It did help as the temps went down in both rear tires for the same mph.

CapriRacer wrote:
Word of caution:

The load on tires varies front to rear and side to side. If you are doing reserve capacity calculations you have to account for this. If you've weighed the trailer, tire by tire, then you know what the variation is.

But if you weighed your trailer axle by axle, I'd recommend to use a 10% figure for the worst case - and if you weighed your trailer as a whole (that is, not axle by axle, or tire by tire), then I'd recommend using 15%.

To put this in perspective, RVUSA quoted some figures, but didn't account for the variation - and at 12.7%, he just might have an overloaded tire. But we can't be sure without individual tire weights.

And there in lies the problem with trailers with 7K axles and GAWR being delivered with OEM tires rated to 3520 pounds. Or de-rated 7K axles with GAWR of 6750 and tires rated to 3420. One of the largest RV trailer manufacturers(Keystone) routinely does this. Duro actually re-branded 3420/80 tires to 3505/85 to install them on Carriage trailers with 7k axles a few years back. I saw it in person, branded by hand into the sidewall.

Why are the manufacturers being allowed to install minimal tires? Are they truly just delivery and display tires, and need to be labeled as such. These special trailer tires already carry load ratings that are inflated by about 15% to start with, based on the 65 MPH speed restriction and lower testing standard.

What I am posting here in this post is at the core of way to many of the tire threads. Seem like we are still at the same point in the conversation we were at in 2008 or 2009 and nothing much has changed, except that some manufacturers are now offering options for LRG tires and have switched to wheels rated for them. It has not however been an easy route to get this far, with the heavy marketing we have seen from the ST tire industry.

Tredit and Tireco sell wheel/tires pre-mounted with full knowledge that the trailer manufacturer is going to use them in applications that use them at at or very near their max ratings. Trailer manufacturers are not even being required to size to the heaviest tire position much less heaviest axle. Both of these would require loading sample trailers similar to what an user would do.

Chris

Word of caution:

The load on tires varies front to rear and side to side. If you are doing reserve capacity calculations you have to account for this. If you've weighed the trailer, tire by tire, then you know what the variation is.

But if you weighed your trailer axle by axle, I'd recommend to use a 10% figure for the worst case - and if you weighed your trailer as a whole (that is, not axle by axle, or tire by tire), then I'd recommend using 15%.

To put this in perspective, RVUSA quoted some figures, but didn't account for the variation - and at 12.7%, he just might have an overloaded tire. But we can't be sure without individual tire weights.

Me Again wrote:
RVUSA my calculator has 330 lbs divided by 2500 at 13.2 percent excess capacity, which is better than most. That assumes a fully loaded trailer with a light 19 percent pin weight in my earlier example.

Tires are 2830 not 3850??? I assume you bought or had wheels that were rated to 80 inflation for E rated tires.

Chris

I have 15" tires on my 5th, 225/75R15. They have a load rating of 2830.

I know you know how to do this, I am just showing how I get my numbers.

2830 * 4 = 11320 load capacity.

GVWR of 12340, minus your original 20% pin weight gives 9872 load weight on the tires (not considering load balance, one axle is heavier on mine, it's nose high with a less than 20% hitch weight).

So each tire is assumed to see 2468 pounds.
2830 - 2468 = 362 pounds of reserve capacity for each tire.
2830 / 362 is 12.7% so I have just over 10% reserve capacity.

I have never weighed it even though it rides nose high as the tires never get hot. The fronts are barely warm to the touch and the rears are a tad warmer. I don't carry much water but I do carry a huge amount of tools and what nots, the bay is stuffed... correction was stuffed. I'm still scratching my head as to how I got all of this stuff that has no place to go in the 38 foot rv packed into a 31 foot 5th. Baffling and a bit irritating as I am a bonifide pack rat and really don't wanna dump any of it. I might need it some day you know. LOL

Me Again wrote:

CKNSLS wrote:

or the trailer manufacturer undersized the Carlisle OEM tires without the proper reserve capacity and caused issues.

You never answered my inquiry about your rig and excess capacity with the tires you are using.

Chris

And I not going to! Your position is what it is.

CKNSLS wrote:

or the trailer manufacturer undersized the Carlisle OEM tires without the proper reserve capacity and caused issues.

You never answered my inquiry about your rig and excess capacity with the tires you are using.

Chris