Tires, tires, and more tires....it's making me crazy!

[LCowan]

Ok everyone I hate to beat this topic to death, but I really need some recommendations. I have read so many posts on this site concerning tires and most of the tire advice seems to be for the bigger rigs. I have researched and researched tires until it just seems to be a spinning circle....my head is about to explode. We have a 2011 NT 24 RBS with a GVWR of 6900 lbs. The trailer came with towmax tires that looked really good, but we knew nothing about the reputation of these tires until we already owned the trailer and started researching. The tires are stamped with a 2012 manufactured date so we feel we need to replace these soon. Our tire size is 205/75/14 and the only thing we can find that are D rated tires are carlisles (which we really don't want because of the reviews on them) and Kumhos that come in our size with a D rating. After researching, we were set on the maxxis tires, but they don't come in our size with a D rating. We are steering clear of GY marathons. HELP...what is a person to do?????? We have considered changing the wheels to accommodate a bigger tire, but that costs extra right now and not even sure yet if that is a possibility.

Brad and Lisa

 

[SNOKING]

The new Carlisle Radial Trail RH seems to be doing pretty well according to users. In that size they come in LRC and LRD.

http://www.carlstargroup.com/product/tires/trailers-toy-haulers-towables/radial-trail-hd

Chris

 

[Miltp920]

You make me laugh - Thanks for that. My head was spinning just like you speak of, but I was shopping for the heavier rig. I will let those who are towing at your lighter weight give you advice. I am really only familiar with 15,500 lbs. Good Luck. I am PROUD of you for doing the research! I did buy the Carlisle Radial RH, but it was rated for my heavier rig.

 

[LCowan]

Thanks Chris...we will take a look at the website you provided.

Lisa

- - - Updated - - -

Miltp920,
Thanks for your reply. Maybe we will give Carlisle some consideration...we will see. Glad I could make you laugh because sometimes that's all we can do.

 

[windviewer]

we wont be there (hopefully) for another 2-3 years but appreciate you asking and posting what you decide on (prowler tt 7400 lbs gvr). the tire questions/answers on these forums is exhausting

 

[mlpeloquin]

Maxis load inflation chart rates the 205/75/14 at 1760lbs at 50 psi. Maxis has a good reputation for the smaller tire sizes.

http://www.maxxis.com/trailer/trailer-tire-loadinflation-chart

They also make the same size tire in a 8 ply with 65 psi at 2150lbs. - http://www.maxxis.com/catalog/tire-122-st-radial-m8008

 

[LCowan]

mlpeloquin,
We would buy the maxxis if we could find the 8 ply in our tire size, but we just don't see it on the chart provided. Our we missing something?

 

[SNOKING]

mlpeloquin,
We would buy the maxxis if we could find the 8 ply in our tire size, but we just don't see it on the chart provided. Our we missing something?

LRC only in that size. Chris

http://www.maxxis.com/catalog/tire-122-st-radial-m8008

 

[mlpeloquin]

mlpeloquin,
We would buy the maxxis if we could find the 8 ply in our tire size, but we just don't see it on the chart provided. Our we missing something?

Sorry. My old eyes didn't see it was the 15 inch instead of 14 inch.

Did find a 14 inch load range D 65 psi at etrailer. https://www.etrailer.com/Tires-and-Wheels/Kenda/AM10235.html Don't know much about them though.

Carlisle also makes a 14 inch load range D sold at Americas Tire also known a Discount Tire.

 

[Jim.Allison]

Have you thought about this.......Invest in the tires and rims that you want and need (perhaps off "take offs") off EBay or Craigs list. Then sell the set of tires and rims that you have. Of course my tires and rims were 16s with the "Blowmax tires, and I had a larger market, but they were for sale on Craigs List for only a matter of hours before they sold, and I got a little less than a $1000 bucks for all 5 of them. There are many utility trailer owners out there that only run used tires, my buyer was happy to get them.

No matter what you do, be sure to check your clearances. But moving up a rim size should open up a whole other world for you as far a selection is concerned. Remember that the load rating for a ST is higher because it is not a steering tire, LTs are lower because the service factors are more onerous for a passenger vehicle. You could conceivably run a LT that is marginal for your application, and be better off than any ST of the same size. Unfortunately there are very few if any LTs or passenger car tires in a 14 in, and a cursory look at tire rack did not yield a passenger tire that would come within 900 lbs of your GVWR.

I just bought a set of 15 inch Carlisle for my utility trailer, and they looked pretty good, we will see though. If you think RV tires are trouble, think again, utility trailers are hard on tires, and most die young. After all they run flat, get pulled over obstacles, run to fast, run overloaded, go to the dump and get punctured, get repaired, and sit 6 months, before starting the process over. I'm hoping that these Carlisle will run better than the "off brand" STs that I had before. I really liked the warranty that Discount offered with them, I hope they know what they are getting into.

If discount has that new Carlisle in 14 inch, perhaps you should at least go look at them, maybe you could blaze a trial for other NT 24s, ask about their warranty.

 

[tireman9]

JIm, Yes tire stuff can be confusing. Especially when some post about problems but don't have the training to understand the "why" of the problem they had.

As a tire engineer, my advice is:
1. Confirm your actual load on your tires. - Trailer fully loaded
2. You need to have tires that are capable of handling the measured load + 15%.
3. Realize that many trailers are built with the lowest cost tires that barely exceed the minimum requirements and the RV company is simply guessing on how much "stuff" you will actually carry
4. Based on actual measurement of tens of thousands of RVs over half have a tire or axle in overload.
5. Basically tires fail for one of two reasons. They have a Run Low Flex Blowout because they are leaking air (puncture, cut or leaking valve) ANY tire will fail if you don't keep air in it. You can prevent this type of failure by running a TPMS so you get a warning as soon as the tire has lost a few psi. The second reason is longer term overload, age and heat. Running faster than the speed rating of the tires. Until this year ST type tires were rated 65 mph MAX. Now (2016) some are rated for 75. You can learn if you have a tire that is in the process of having a belt or tread separation with proper inspection procedure. The thing you want to do is lower the likelihood of a separation. Interply Shear is inherent with trailers and the best you can do is to run the tire sidewall pressure

 

[Bones]

JIm, Yes tire stuff can be confusing. Especially when some post about problems but don't have the training to understand the "why" of the problem they had.

As a tire engineer, my advice is:
1. Confirm your actual load on your tires. - Trailer fully loaded
2. You need to have tires that are capable of handling the measured load + 15%.
3. Realize that many trailers are built with the lowest cost tires that barely exceed the minimum requirements and the RV company is simply guessing on how much "stuff" you will actually carry
4. Based on actual measurement of tens of thousands of RVs over half have a tire or axle in overload.
5. Basically tires fail for one of two reasons. They have a Run Low Flex Blowout because they are leaking air (puncture, cut or leaking valve) ANY tire will fail if you don't keep air in it. You can prevent this type of failure by running a TPMS so you get a warning as soon as the tire has lost a few psi. The second reason is longer term overload, age and heat. Running faster than the speed rating of the tires. Until this year ST type tires were rated 65 mph MAX. Now (2016) some are rated for 75. You can learn if you have a tire that is in the process of having a belt or tread separation with proper inspection procedure. The thing you want to do is lower the likelihood of a separation. Interply Shear is inherent with trailers and the best you can do is to run the tire sidewall pressure

Did you forget road hazards that are forgotten and can show up much later after the hazard is hit.

 

[SNOKING]

JIm, Yes tire stuff can be confusing. Especially when some post about problems but don't have the training to understand the "why" of the problem they had.

As a tire engineer, my advice is:
1. Confirm your actual load on your tires. - Trailer fully loaded
2. You need to have tires that are capable of handling the measured load + 15%.
3. Realize that many trailers are built with the lowest cost tires that barely exceed the minimum requirements and the RV company is simply guessing on how much "stuff" you will actually carry
4. Based on actual measurement of tens of thousands of RVs over half have a tire or axle in overload.
5. Basically tires fail for one of two reasons. They have a Run Low Flex Blowout because they are leaking air (puncture, cut or leaking valve) ANY tire will fail if you don't keep air in it. You can prevent this type of failure by running a TPMS so you get a warning as soon as the tire has lost a few psi. The second reason is longer term overload, age and heat. Running faster than the speed rating of the tires. Until this year ST type tires were rated 65 mph MAX. Now (2016) some are rated for 75. You can learn if you have a tire that is in the process of having a belt or tread separation with proper inspection procedure. The thing you want to do is lower the likelihood of a separation. Interply Shear is inherent with trailers and the best you can do is to run the tire sidewall pressure

Roger, why do you think that so many Tow Max tires fail. Tow Max and Carlisle both added a Nylon overlay a few years ago. Failures of Tow Max tires continues and the Carlisle Radial Trail RH now seems to be one of the best poly carcass ST tires available now. I believe there is a third reason they fail! That is that they are cheaply made junk in some cases.

BTW, I have long thought that the A/S style tread on many ST tires with breaks in the outer ribs leads to the tire tearing itself apart in tight manuvers.

What kind of mirrors and magic do you think they are using to raise the speed restriction. For years we have been told that the increase loading was allowed based on the 65 MPH speed restriction. Carlisle and their bass boat customers seem to have driven the need for speed and was one of the first to raise the speed restriction. Chris

 

[Jim.Allison]

I'm not a tire engineer. But I did stay at a Holiday Inn last night.

 

[LCowan]

Thanks Jim and Amy,
We are considering looking at different rim size and asking the tire shop if it will work with our trailer. We should just talk to discount tire to see what they say about the Carlisle. Thanks for the info.

Lisa

 

[tireman9]

Roger, why do you think that so many Tow Max tires fail. Tow Max and Carlisle both added a Nylon overlay a few years ago. Failures of Tow Max tires continues and the Carlisle Radial Trail RH now seems to be one of the best poly carcass ST tires available now. I believe there is a third reason they fail! That is that they are cheaply made junk in some cases.

BTW, I have long thought that the A/S style tread on many ST tires with breaks in the outer ribs leads to the tire tearing itself apart in tight manuvers.

What kind of mirrors and magic do you think they are using to raise the speed restriction. For years we have been told that the increase loading was allowed based on the 65 MPH speed restriction. Carlisle and their bass boat customers seem to have driven the need for speed and was one of the first to raise the speed restriction. Chris

Without more facts and data we can spend all night guessing. Facts like actual tire loads are very important. Some RVs have sign9ficant variation between axles and side to side so you can't simply get the total and divide by the number of tires.

I agree that the argument for more load capacity due to less tread depth and lower speeds doesn't stand up to close examination IMO.

RE Speed Late last year there were investigations into dumping (low pricing) of some tires. This brought up ST type tires and their lack of reasonable speed rating. The faster speed rating (75 mph) is not covered by Federal Regulation. IMO the bottom line problem is that ST tires use load calculations from 1960's and Federal Test requirements from the early 70's unlike Passenger and LT that had their performance requirements updates in 2002.

Very few trailers come with tires that provide any meaningful margin on load capacity. This coupled with the data that shows that most RVs have a tire or axle in overload kind of points to the most likely problem. Too small tires (low load capacity) coupled with speed at or above their max rating 65 mph and poor maintenance ( continuous inflati0on monitoring) results in high failure rates.

Trailers also see significant higher Interply Shear loading than motorized vehicles (trucks & motorhomes) and this force is trying to tear the belts apart. IMO a 15% load capacity margin would be a minimum and maybe something closer to 25% might be needed to get life on trailers sililar to what is seen on motorized vehicles.

 

[Bones]

Ok everyone I hate to beat this topic to death, but I really need some recommendations. I have read so many posts on this site concerning tires and most of the tire advice seems to be for the bigger rigs. I have researched and researched tires until it just seems to be a spinning circle....my head is about to explode. We have a 2011 NT 24 RBS with a GVWR of 6900 lbs. The trailer came with towmax tires that looked really good, but we knew nothing about the reputation of these tires until we already owned the trailer and started researching. The tires are stamped with a 2012 manufactured date so we feel we need to replace these soon. Our tire size is 205/75/14 and the only thing we can find that are D rated tires are carlisles (which we really don't want because of the reviews on them) and Kumhos that come in our size with a D rating. After researching, we were set on the maxxis tires, but they don't come in our size with a D rating. We are steering clear of GY marathons. HELP...what is a person to do?????? We have considered changing the wheels to accommodate a bigger tire, but that costs extra right now and not even sure yet if that is a possibility.

Brad and Lisa

I want to get back on your question. I though about what you would like to do and lets make things a little simpler. Your current tires have a diameter to them. I just looked up the Diam and it is about 26 inches. So now you will need to measure how much space you have from the top of your tire to the underside of the camper. Next you will want to measure the arc distance in your springs. That should give you a rough travel distance more or less of the tire. Take that measurement and subtract from the height from the top of the tire to the bottom of the camper. The measurement that is left can be added to half the diameter of 26 which is 13 inches. If you move to a 16 inch rim your tire may be around 31 inches diameter. that half will be 15.5 inches. So by moving to a larger tire you will be closer to the underside of the camper by 2.5 inches and closer to the other axle and tire by 2.5 inches. You will also have to make sure that the tires wont rub together too. If your axle is on the top of the spring you and reverse the axle to the bottom of the spring to gain extra distance to put a larger tire on. Take lots of measurements draw it out on a piece of paper and post what you have. Take pictures. Another note is that all this will raise the center of gravity for the trailer. If you have wide track then you should be good on tire to tire distance. Don't guess take measurements. To measure your spring travel take a level across your shackles and measure from the level down to the arch.

Another thing is with the center link, that moves the tire as well but lets start with this here.

 

[wdk450]

You might phone Tredit tire, E-Trailer or Trailer Tires.com for advice. Or talk to a local tire expert you trust.

 

[SNOKING]

I want to get back on your question. I though about what you would like to do and lets make things a little simpler. Your current tires have a diameter to them. I just looked up the Diam and it is about 26 inches. So now you will need to measure how much space you have from the top of your tire to the underside of the camper. Next you will want to measure the arc distance in your springs. That should give you a rough travel distance more or less of the tire. Take that measurement and subtract from the height from the top of the tire to the bottom of the camper. The measurement that is left can be added to half the diameter of 26 which is 13 inches. If you move to a 16 inch rim your tire may be around 31 inches diameter. that half will be 15.5 inches. So by moving to a larger tire you will be closer to the underside of the camper by 2.5 inches and closer to the other axle and tire by 2.5 inches. You will also have to make sure that the tires wont rub together too. If your axle is on the top of the spring you and reverse the axle to the bottom of the spring to gain extra distance to put a larger tire on. Take lots of measurements draw it out on a piece of paper and post what you have. Take pictures. Another note is that all this will raise the center of gravity for the trailer. If you have wide track then you should be good on tire to tire distance. Don't guess take measurements. To measure your spring travel take a level across your shackles and measure from the level down to the arch.

Another thing is with the center link, that moves the tire as well but lets start with this here.

If you go from a 26" tire to a 31" tire the distance between them decreases by 5", not 2.5". Chris

 

[Jim.Allison]

yup 5 inches. And that is a lot of adjustment between those tandems. But there may be a lower profile in a 15 or a 16 that will fit the application. Nevertheless, measuring is important to any mod, best not to stray in terms of inches but rather fractions of inches. Another important spec is the wheel offset, most, if not all trailers have a 0 offset. if you add an offset you will stress the bearings, and you will most definitely have to do the math as far as clearance issues with that factored in. The further you stray the sharper your pencil will need to be.