ST trailer tire 75 mph rated

[rexlion]

For those who prefer to tow a little faster than 65 mph, as well as for those who would like some extra cushion in their tires' speed rating, I recently learned that Hercules ST tires are rated for 75 mph. Just wanted to let folks know about this additional option. I am getting one put on my cargo trailer next week (they had to order it from the warehouse, the store didn't stock it).

[gmw_photos]

rbpru wrote:
.....snip.....

Unfortunately, the customer drives quality and price.

....snip.....

The fact is, if you have the money you can buy whatever level of quality you wish.

....yes, and with that, I think this whole discussion has likely run it's course. I B done.....

[rbpru]

Even if you assume the TT industry is a bunch of money grubbing fools, they are just a portion of the ST tire industry. Many horse trailers, cargo trailers, farm trailers to name a few also use ST tires. Of course they could also be money grubbing fools.

The fact remains, that few if any, of the LT tire makers, from the lowest to the highest quality manufacturers recommend replacing your TT’s ST tires with their LT tires. They would rather loose sales. Considering the 300,000 TT and 5vers sold each year that is a lot of lost sales. Again, what do these people know; they just make the things.

It is true, I am at times critical of the TT industries especially when we hear horror stories of some of the stupid mistakes that are made. Unfortunately, the customer drives quality and price. Hence it seems that only when things go wrong, do we hear complains about quality. The fact is, if you have the money you can buy whatever level of quality you wish.

It is likely that with the purchasing power of the RV industry, if they felt that LT tires would do the job, they would switch to LTs in a heartbeat to capture the savings of increased volume. The fact that the ST tires were developed by the Tire industry for trailer service, rather than expand the role of LT tires which were already seeing some TT use also says a lot. But again we all know these folks are a bunch of idiots who know nothing about TTs and tires.

[Huntindog]

rbpru wrote:
While I cannot comment on tire compounds and construction, I can say that the primary reason the RV and Tire industries recommended ST tires is their stiffer side walls and the rolling resistance of their tread design. These characteristics and a recommended speed rating of 65 mph are what the industries feel is proper.


If a person feels they are wrong or these features are less important than those found in LT tires, so be it.

There are not enough LT tire in trailer use to draw any meaningful conclusions of performance, when compared to the millions of ST tires placed into trailer service every year.

Here is a post you made about the quality in the TT industry:

rbpru wrote:
I just watch a program on the Travel Chanel about RVs constructed of 2x4s, 4x4s redundant bracing; that even had a house like appearance and a sleeping loft. Tumble Weed will build you an 18 footer for a measly $57,000.00.

The theme in the RV industry seems to be; build them as fast as you can, the best you can. They sell over 300,000 TTs and 5vers every year. They must know what will sell.

It is not that quality RVs are not out there, people just do not want to pay the price.

The car industry was that way until the consumer demanded better quality. However that increase quality carried an increased price.

I find it interesting that you trust these manufacturers to make the best tire choice available, when your views on how they build them cheaply are what they are.
(link)

rbpru's views on the TT industry

[gmw_photos]

And bear in mind that not all are rated at 65mph. As I posted earlier, the ST tires I took off my camper were rated at 62mph ( I believe that is 99kph ? ).
Everything has to have a design limit. A "redline" to put it another way. It may be pressure. Or heat. Or rpm. Or reciprocating speed for some devices ( pistons and rods for instance ). Etc, etc. So the manufacturer states those limits and it's up to us users to abide by those limits.

Coolbreeze, let us know what the tire companies tell you as to an "explaination of WHY the limits are set where they are".

I solved the problem in an easier manner: I buy tires that have limits ( load, speed ) that are considerably higher than where I operate them.

[Huntindog]

coolbreeze01 wrote:

gmw photos wrote:
The term "redline" in my opinion is used to describe the use of any system "near it's design limit". This could be rpm, as you point out, or it could be pressure, weight, or any other parameter that would have "upper limit" that beyond which is likely to result in a catastrophic failure.

What? You said:

As one of the tire engineers who used to comment on this forum has said, you are in effect running these tires "near or at redline, when towing at these speeds".
Who here thinks running your trucks engine near or at redline all day is a good idea ?
One more reason to buy products that have more reserve head room above what we normally need to operate.

Still doesn't address the 14" vs 16" ST tire RPM's at speed question.

Why is 65 MPH the magic tire disintegration number, regardless of tire diameter or RPM?

It's a fair question. I have a pretty good idea, but it is just an opinion, and some here haven't liked my other opinions.

My suggestion is to ask the manufacturers of those tires. They are the ones that designed and built them as well as molding the 65 MPH max on the sidewall.
They will be the ones best qualified as to why the ratings are what they are.

Once you get their response, you can post it here on this forum.. Be sure to let them know that you intend on doing that, as you may need their permission to do so.

[gmw_photos]

coolbreeze01 wrote:

gmw photos wrote:
The term "redline" in my opinion is used to describe the use of any system "near it's design limit". This could be rpm, as you point out, or it could be pressure, weight, or any other parameter that would have "upper limit" that beyond which is likely to result in a catastrophic failure.

What? You said:

As one of the tire engineers who used to comment on this forum has said, you are in effect running these tires "near or at redline, when towing at these speeds".
Who here thinks running your trucks engine near or at redline all day is a good idea ?
One more reason to buy products that have more reserve head room above what we normally need to operate.

Still doesn't address the 14" vs 16" ST tire RPM's at speed question.

Why is 65 MPH the magic tire disintegration number, regardless of tire diameter or RPM?

Well. Ok. Since you didn't care for my last clarification of analogy, how about this:

you asked: "Are 14" ST tires built better than 15" and 16" ST tires? "

....and my reply is: I don't know. I don't use ST tires anymore. In 14", 15" or 16" sizes.
So I reckon you'll have to ask someone who cares about those tires 🙂 :B

[SprinklerMan]

Why even make a tire with a maximum speed of 65 MPH or even 75 mph ? People generally drive 10 to 15 mph over the speed limit . Sure when the national speed limit was 55 it was close . But there are plenty of roads 65 MPH and others higher than that .

[coolbreeze01]

gmw photos wrote:
The term "redline" in my opinion is used to describe the use of any system "near it's design limit". This could be rpm, as you point out, or it could be pressure, weight, or any other parameter that would have "upper limit" that beyond which is likely to result in a catastrophic failure.

What? You said:

As one of the tire engineers who used to comment on this forum has said, you are in effect running these tires "near or at redline, when towing at these speeds".
Who here thinks running your trucks engine near or at redline all day is a good idea ?
One more reason to buy products that have more reserve head room above what we normally need to operate.

Still doesn't address the 14" vs 16" ST tire RPM's at speed question.

Why is 65 MPH the magic tire disintegration number, regardless of tire diameter or RPM?

[gmw_photos]

The term "redline" in my opinion is used to describe the use of any system "near it's design limit". This could be rpm, as you point out, or it could be pressure, weight, or any other parameter that would have "upper limit" that beyond which is likely to result in a catastrophic failure.

[coolbreeze01]

Since redline typically refers to RPM's, and a 14" ST tire turns more RPM's at any speed than 15" ST tires, not to mention 16" ST tires.

Are 14" ST tires built better than 15" and 16" ST tires?

[gmw_photos]

myredracer wrote:

gmw photos wrote:


As one of the tire engineers who used to comment on this forum has said, you are in effect running these tires "near or at redline, when towing at these speeds".
Who here thinks running your trucks engine near or at redline all day is a good idea ?
One more reason to buy products that have more reserve head room above what we normally need to operate.

EDIT: which sort of brings us full circle back to the original title of this thread. If you like ST tires, and if you can find one with a 75mph rating, then that gives you additional reserve for that aspect of performance.

Is it possible that Marathons (compared to the typical ChinaMaster tire) have more of a built-in reserve and are a better tire if GY states it is okay to run them at up to 75 mph? Either with the added psi or occasional 65+ mph without adding psi?

I suppose anything is possible. I also would suspect that none of us outside of goodyear engineering knows what is or is not different about these tires compared to others in the same category.
The whole idea of being able to run these tires at 75 psi seems contradictory to me. If 75 really is the max number, then why don't they mold that number into the writing on the sidewall instead of 65 ? If it's an "advantage", you'd think they would want to capitalize on that, and make it easily known. It's like they are trying to keep some critical piece of usage data secret. That doesn't make sense to me.

[myredracer]

gmw photos wrote:


As one of the tire engineers who used to comment on this forum has said, you are in effect running these tires "near or at redline, when towing at these speeds".
Who here thinks running your trucks engine near or at redline all day is a good idea ?
One more reason to buy products that have more reserve head room above what we normally need to operate.

EDIT: which sort of brings us full circle back to the original title of this thread. If you like ST tires, and if you can find one with a 75mph rating, then that gives you additional reserve for that aspect of performance.

Is it possible that Marathons (compared to the typical ChinaMaster tire) have more of a built-in reserve and are a better tire if GY states it is okay to run them at up to 75 mph? Either with the added psi or occasional 65+ mph without adding psi?

[gmw_photos]

myredracer wrote:
...snip....

What I don't understand is why ST tires are designed and rated to run at max. 65 mph when there are an awful lot of roads out there where it's easy to get up to 70 mph or maybe more, especially if you want to go with the flow. 65 mph leaves a zero cushion. I tow at max. 65.00 mph but often on the interstate, I'd rather run in the 65 - 70 mph range to keep up with the prevailing flow of traffic.

As one of the tire engineers who used to comment on this forum has said, you are in effect running these tires "near or at redline, when towing at these speeds".
Who here thinks running your trucks engine near or at redline all day is a good idea ?
One more reason to buy products that have more reserve head room above what we normally need to operate.

EDIT: which sort of brings us full circle back to the original title of this thread. If you like ST tires, and if you can find one with a 75mph rating, then that gives you additional reserve for that aspect of performance.

[myredracer]

I can run our GY Marathons between 66 & 75 mph just by adding another 10 psi as per their bulletin PSB #2014-01.

They say "If Goodyear tires, with the ST designation, are used at speeds between 66 and 75 mph (106 km/h and 120 km/h), we recommend the cold inflation pressure be increased by 10 psi (70 kPa) above the recommended pressure based on the trailer placard for normal inflation and load conditions." Note "recommend".

This seems somewhat confusing as I thought it's typically recommended to run your STs at the max. sidewall psi? I run ours at 65 psi. So what will happen if I pump them up to 75 psi for some extended freeway driving and then leave them at 75 for the rest of a trip which could be mostly 65 mph and under? I'd rather leave them at 65 psi and stay under 65 mph.

Does GY build their Marathons differently to be able to handle 75 mph?

I would hazard a guess that 99% of TT owners don't know how to take proper care of ST tires (correct psi, regular checking of psi, max. speed, potholes/bumps, UV rays, etc.). Nobody explains proper care to a new TT buyer. We camped a couple of months ago with some friends and before we left I asked if they had checked their tire pressure (LRD). Three were at 60 +/- psi but one was at 52 psi. They had no clue of the importance of correct pressure and regular checking. There has to been many thousands of TTs running around with under-inflated tires...

What I don't understand is why ST tires are designed and rated to run at max. 65 mph when there are an awful lot of roads out there where it's easy to get up to 70 mph or maybe more, especially if you want to go with the flow. 65 mph leaves a zero cushion. I tow at max. 65.00 mph but often on the interstate, I'd rather run in the 65 - 70 mph range to keep up with the prevailing flow of traffic.

[Atlee]

Michelins are built all over the world, including USA. However, Michelin is a French company.

Sport45 wrote:

Huntindog wrote:
Gonna have to dash your hopes.
They say "The United Kingdom" on the sidewall.
Since they are Michelins, then that likely means Germany.

You will get over it with therapy.:B

Was that meant to be a poke at the Brits, the Germans, or both? :@