Community Forums

Hit_the_Rhod · 10-12-2015, 04:44 PM

Quote:

Originally Posted by 450Donn

how can you say this? OP does not specify what his ST tires are/were nor does he indicate the LT tires information.

Check out the signature information in the original post. He lists the year, make and model of his trailer. From that, you can find the load ratings of each axle, the ratings of the original tires, and then you can get the load ratings of LT tires offered for his rims. Easy, Peasy

C130 · 10-13-2015, 06:47 AM

I ran Michelin XPS RIBS on my previous Fuzion. Yes, they had a lower weight rating but I never had a blowout. That's the important thing to me but others may choose the ST tire then constantly discuss blowouts and tire choices. My plan is to replace my current tires with LT tires also. I've yet to read a thread discussing blowouts and LT tires as the issue.

Dtwallace · 10-14-2015, 02:58 AM

X2 on changing all over to (LT). With all the trailers I've ever had, I've never had a single tire failure using (LT) light truck tires, and many with trailer only tires. I'm a firm believer (LT's) Are a better choice when it comes time to change out. And I know I have, and still do on occasion overload my trailer tires.

jacknife · 10-16-2015, 06:03 AM

The load rating on an LT tire may be less but the reserve is beyond the load rating where the ST has no reserve.

J Birder · 10-16-2015, 07:05 AM

Quote:

Originally Posted by jacknife

The load rating on an LT tire may be less but the reserve is beyond the load rating where the ST has no reserve.

Can you document that?

Joel

justafordguy · 10-16-2015, 07:12 AM

I always thought that the LT tires were rated for a lower weight because they are rated for a higher speed. At 65 MPH I bet they have a higher cap than the ST.

caissiel · 10-16-2015, 06:42 PM

LT tires is my choice over ST tires for my trailer applications. OR tires will last much longer with same loading and size. The larger load capacity of ST tires is only in dreams. They will fail and damage the unit much sooner.

Fred1609 · 10-16-2015, 11:43 PM

Quote:

Originally Posted by jacknife

The load rating on an LT tire may be less but the reserve is beyond the load rating where the ST has no reserve.

This if from an older thread but I thought it might help.....

I've been searching for ST vs. LT info...
I found this on another forum and thought it might be worth the read...

I copied this from another thread about LT vs ST tires:
++++++++++++++++++++++++++++++++++++++++++++++++

Portion of a post by Mike Mitchell, NuWa (HitchHiker) CEO in a discussion regarding trailer tires on the NuWa Owner's Forum.

As we banter about regarding tire types and loading, I believe that we are finally starting to understand a few important things.

I have asked many times for someone to explain how a ST tire can be rated to carry more weight than a LT tire in a similar size, without a good answer.

The answer lies in what is called reserve capacity. To quote from Trailer Parts Superstore and this same statement exist on just about every tire site:

HEAVY DUTY 'LT' TRUCK / TRAILER TIRES
'LT' signifies the tire is a "Light Truck/Trailer" series that can be used on trailers that are capable of carrying heavy cargo such as equipment trailers.

If a tire size begins with 'LT' it signifies the tire is a "Light Truck-metric" size that was designed to be used on trailers that are capable of carrying heavy cargo or tow vehicles. Tires branded with the "LT" designation are designed to provide substantial reserve capacity to accept the additional stresses of carrying heavy cargo.

So what is reserve capacity? It is capacity beyond the rating of the tire, capacity that is held in reserve. This reserve capacity comes from the heavy-duty sidewall of the LT type tires. LT's rank at the top of the list when we look at P, ST and LT tires.

Now I finally have an answer to how a ST tire can be rated to carry more weight than a LT tire of similar size.

The ratings of ST tires infringe into the reserve capacity of the tire. This is double bad, because the design of the ST gives us a tire with less reserve capacity to start with as it has a lighter sidewall to start with as most ST tires are much lighter than their LT counterparts.

To quote one tire site:
"Put a different way, the load carrying capacity of an ST tire is 20% greater than an LT tire. Since durability is strictly a long term issue - and the results of a tire failure on a trailer are much less life threatening than on a truck - the folks that set up these load / inflation pressure relationships allow a greater......ah......let's call it load intensity."

There it is in print to be read. They make a calculated decision to give the ST tire a higher load rating because a failure is less life threatening.

I have on a number of occasions pointed out the weight difference between the different tires and have been told that does not matter. Well it does matter. The rubber in the average tire only makes up around 40 some percent of its weight, the rest is in the steel belts, gum strips, steel beads, and the carcass plies. The remaining 60 or so percent of the stuff in a tire is what builds in the reserve capacity.

So to review again, here are some weights:
1. Michelin XPS RIB LT235/85R16 LRE (rated to 3042lbs) Weight 55.41
2. Goodyear G614 LT235/85R16 LRG (rated to 3750lbs) Weight 57.5
3. Bridgestone Duravis R250 LT235/85R16 LRE(rated to 3042lbs) Weight 60
4. BFG Commercial TA LT235/85R16 LRE(rated to 3042lbs) Weight 44.44
5. Uniroyal Laredo HD/H LT235/85R16 LRE(rated to 3042lbs) Weight 44.44
6. GY Marathon ST235/80R16 LRE(rated to 3420lbs) Weight 35.4

So which tires on the list have the most reserve capacity? Well that is not a completely simple answer, as one of the tires is a G rate 110 lb tire and the rest are LRE at 80lb inflation. So if we disregard the G614, then the Michelin XPS RIB and the Bridgestone Duravis R250 due to their all-steel ply construction will have the most reserve capacity inherent in their construction. The twin Commercial TA and Laredo will be next and the Marathon would have little or no reserve capacity available because it was used up in its higher load rating, AND because of it's much lighter construction it had much less inherent reserve capacity to start with.

So what have we learn from this?

I think that the first thing that we learned was that a LT tire can be used at or near it max rated loading without having issues, as they built with "substantial reserve capacity to accept the additional stresses of carrying heavy cargo".

The second thing we may have learned is why ST tires are failing on mid to larger 5th wheels, in that they do not have inherent reserve capacity beyond that rated max loading. Again this is because they have less reserve capacity to start with and their greater "load intensity" used up any reserve capacity that might have been available.

Now, here is an interesting bit of information. I just called Maxxis Tech Line and asked the weights for two tires.

ST235/80R16 LRD 3000 lb rating at 65 lbs of air weights 38.58
ST235/80R16 LRE 3420 lb rating at 80 lbs of air weights 43.43

What??? The Maxxis load range E tire weights almost the same as the Commercial TA?? This is a ST tire that has heavier construction than the GY Marathon at 35.4 lbs. So it has more inherent reserve capacity due to its heavier construction.

Those that claimed its virtues maybe did not know why it was a better ST tire than some of the others, but there it is! It is a heavier built tire with more reserve capacity.

So as one chooses a replacement tire or is asking for an upgrade on a new trailer please get educated on where the reserve capacity exist. Is it inherent in the tire you choose or do you have to factor it into the weight rating of the tire you choose.
__________________

andy29847 · 10-17-2015, 03:41 AM

That is a lot of talk here I don't agree with. Here is how I think about it.

ST tires are trailer use only.

LT tires can be used for trailer, steer, or drive axles.

LT tires are rated lower because they have to allow for the driving force when used on the drive axle and the steering forces when used on steer axles.

Tires hold the air, air holds the weight - my LT tires hold 105 pounds

My LT tires are rated for 3300 pounds (Hankook F19 7.5r16LT). They would be rated in excess of 4000 pounds if they were rated for trailer use only.

Even when rated at 3300 pounds, the tires exceed the weight carried on the axles of my trailer (GVW - tongue weight).

It is easy to find many stories where ST tires blew up. Why do people keep using them?

One of my original ST tires blew apart at 5000 miles. I took the others off when that happened. I found that one of the tires, on the other side of the trailer, and on a different axle, showed signs of coming apart, even though it still had 80 pounds of air in it.

Considerations when switching to LT tires are rim size (correct width), rim pressure rating (my 16" wheels are rated for 110 pounds), and valve stem rating (my trailer came with load range E tires and valve stem rated for 80 pounds - I had to change to bolt on all metal valve stems).

A Tire Pressure Monitoring System (TPMS) is worth it weight in gold, especially with trailer tires.

FastEagle · 10-17-2015, 05:59 PM

HEAVY DUTY 'LT' TRUCK / TRAILER TIRES
'LT' signifies the tire is a "Light Truck/Trailer" series that can be used on trailers that are capable of carrying heavy cargo such as equipment trailers.

A tire’s design dictates it’s primary purpose. Any tire is what it’s manufacturer says it is. “It can be used as” is not the same as “it’s designed for“.

If a tire size begins with 'LT' it signifies the tire is a "Light Truck-metric" size that was designed to be used on trailers that are capable of carrying heavy cargo or tow vehicles. Tires branded with the "LT" designation are designed to provide substantial reserve capacity to accept the additional stresses of carrying heavy cargo.

If a reserve capacity cannot be measured what value does it have? If you have tires that are rated with a maximum load capacity of 3000# and are carrying 3400# with them how do you explain that they really have enough built-in load capacity for the extra 400#?

So what is reserve capacity? It is capacity beyond the rating of the tire, capacity that is held in reserve. This reserve capacity comes from the heavy-duty sidewall of the LT type tires. LT's rank at the top of the list when we look at P, ST and LT tires.

Anyone with the rudimentary knowledge of tire design knows that a tires strength is provided by its carcass. All add-ons are for durability.

However, there are unknown factors with all tire designs. A manufacturer would not want to take tires to a testing facility and fail any of the required tests. So they will build the tire with a goal set to pass testing. Those types of strengths are not known to the public and are very confidential within each manufacturers need to know factors and are surely never intended for any other purpose.

Now I finally have an answer to how a ST tire can be rated to carry more weight than a LT tire of similar size.

And so do those that build them. The building materials are stronger.

The ratings of ST tires infringe into the reserve capacity of the tire. This is double bad, because the design of the ST gives us a tire with less reserve capacity to start with as it has a lighter sidewall to start with as most ST tires are much lighter than their LT counterparts.

Remember, durability does not add strength.

To quote one tire site:
"Put a different way, the load carrying capacity of an ST tire is 20% greater than an LT tire. Since durability is strictly a long term issue - and the results of a tire failure on a trailer are much less life threatening than on a truck - the folks that set up these load / inflation pressure relationships allow a greater......ah......let's call it load intensity."

I’ll bet no one can get the TRA to confirm any of that mess.

There it is in print to be read. They make a calculated decision to give the ST tire a higher load rating because a failure is less life threatening.

And you really think the DOT will certify a tire design with such parameters?

I have on a number of occasions pointed out the weight difference between the different tires and have been told that does not matter. Well it does matter. The rubber in the average tire only makes up around 40 some percent of its weight, the rest is in the steel belts, gum strips, steel beads, and the carcass plies. The remaining 60 or so percent of the stuff in a tire is what builds in the reserve capacity.

Phooey!

So to review again, here are some weights:
1. Michelin XPS RIB LT235/85R16 LRE (rated to 3042lbs) Weight 55.41
A steel cased tire with taller, more dense treads. An extra steel belt and sidewall inserts for scrubbing. And retreadable to boot. A very durable heavy tire for summer use with commercial vehicles.
2. Goodyear G614 LT235/85R16 LRG (rated to 3750lbs) Weight 57.5
A hybrid ST tire in a modified LT package. A single size steel cased regroovable tire for trailer service.
3. Bridgestone Duravis R250 LT235/85R16 LRE(rated to 3042lbs) Weight 60
Another steel cased commercial use tire.
4. BFG Commercial TA LT235/85R16 LRE(rated to 3042lbs) Weight 44.44
A traditional polyester tire for commercial service.
5. Uniroyal Laredo HD/H LT235/85R16 LRE(rated to 3042lbs) Weight 44.44
Another traditional polyester tire that has a history as OEM on RV trailers.
6. GY Marathon ST235/80R16 LRE(rated to 3420lbs) Weight 35.4
Specifically designed for trailer service only. Short treads reduce weight and help dissipate heat faster.

So which tires on the list have the most reserve capacity? Well that is not a completely simple answer, as one of the tires is a G rate 110 lb tire and the rest are LRE at 80lb inflation. So if we disregard the G614, then the Michelin XPS RIB and the Bridgestone Duravis R250 due to their all-steel ply construction will have the most reserve capacity inherent in their construction. The twin Commercial TA and Laredo will be next and the Marathon would have little or no reserve capacity available because it was used up in its higher load rating, AND because of it's much lighter construction it had much less inherent reserve capacity to start with.
So what have we learn from this?

I think that the first thing that we learned was that a LT tire can be used at or near it max rated loading without having issues, as they built with "substantial reserve capacity to accept the additional stresses of carrying heavy cargo".

Marketing does not always paint a true picture of just what the purpose of a tire design. This is how the DOT describes the LT tire.

“Light truck tire means a tire designated by its manufacturer as primarily intended for use on lightweight trucks or multipurpose passenger vehicles.”

The second thing we may have learned is why ST tires are failing on mid to larger 5th wheels, in that they do not have inherent reserve capacity beyond that rated max loading. Again this is because they have less reserve capacity to start with and their greater "load intensity" used up any reserve capacity that might have been available.

Misleading and undocumentable.

Now, here is an interesting bit of information. I just called Maxxis Tech Line and asked the weights for two tires.

ST235/80R16 LRD 3000 lb rating at 65 lbs of air weights 38.58
ST235/80R16 LRE 3420 lb rating at 80 lbs of air weights 43.43

What??? The Maxxis load range E tire weights almost the same as the Commercial TA?? This is a ST tire that has heavier construction than the GY Marathon at 35.4 lbs. So it has more inherent reserve capacity due to its heavier construction.

Those that claimed its virtues maybe did not know why it was a better ST tire than some of the others, but there it is! It is a heavier built tire with more reserve capacity.

A little more research would have revealed it has more add ons.

So as one chooses a replacement tire or is asking for an upgrade on a new trailer please get educated on where the reserve capacity exist. Is it inherent in the tire you choose or do you have to factor it into the weight rating of the tire you choose.

This document in its original (final) form had several different sources. I’ll not name them but all are known to me. Its been around for six or more years and has more untruths than truths. Mike Mitchell got “hoodwinked” into endorsing it and I’m sure he would not do so today.

tuffr2 · 10-17-2015, 06:11 PM

I am using LT Michelin Rib tires. I will report back if I have any problems.

Oh...I did have a problem putting the Ribs and wheel back into my trailer because they were so much heavier than the ST tires they replaced.

Muscle up if you go to an LT tire.

wingnut60 · 10-18-2015, 08:44 AM

If you think LTs are heavy, try on a 17.5 or a 19.5....

caissiel · 10-18-2015, 10:11 PM

This is all propaganda, ST tires are built cheap and sold at a premium for greater gain without care for the end user. I did switch to LTs because they were cheaper and found out the benefits were overwhelming.