Replacing tires - Page 2

CWtheMan · 11-23-2020, 01:31 AM

Quote:

Originally Posted by bjasin1

If no clearance issues exist, could I go with a 235/85/16 instead of 235/80/16 in Goodyear endurance? That gives me over 3600 lbs per tire at same width and just a 1 inch difference in height. My rig would still be under 13’6”

Yes, However without the approval of the vehicle manufacturer such replacements - by industry standards - would be a misapplication.

IMO, the vehicle manufacturer may not approve the use of ST235/85R16 tires is because the ST235/80R16 can be obtained with a LRF which is the same designated size. (Brands don't play a part in vehicle manufacturer OE tire selections because they are building to a load capacity).

CWtheMan · 11-23-2020, 02:06 AM

Quote:

Originally Posted by JRTJH

Russ,

I "think" (won't take the time to do the research to prove it) that LT tires are manufactured with a 20% reserve capacity and ST tires are manufactured with 0% reserve capacity.

If that's true, then your LT tires with a rating of 3042, actually have 20% more capacity (608.4 in 20% reserve) for an "actual rating of 3650.4 pounds.

Additionally, during the time that your trailer was constructed, Keystone "elected to fit LT tires" on your model. I'd ask you, did they use LT tires with the knowledge that there is a 20% reserve capacity and calculate that into "carried weight" or did they fit the tires with the 20% "reserve that's not used" ???

In other words, did the engineers at Keystone calculate your tires at 3042 pounds or did they calculate them at 3650 pounds ???? Not that it makes a difference at this point, but you may be talking "apples and oranges" or looking at LT tires as replacements, you may be talking "apples and apples" or maybe "apples and squash".... The question becomes: "What will a safety expert witness say about the tires if it ever becomes a "he said/she said" in a court of law" ??????

Using what's on the factory tire label as replacements is the "safe in court" route for replacements, using "a forum recommendations"... Well, not so much if the "gritty hits the fan".....

You really opened up a big "can of worms" with those statements.

If the LT235/85R16 LRE is listed at having a maximum load capacity of 3042# at 80 PSI and that's what the tire manufacturer put on the tire sidewall. It would be a lie for them to then say the sidewall information is just numbers. They might say they tested those tires to a higher standard. In doing so all other brands would say the same thing. It's kind of a standard with ST tire manufacturers to say they tested to a higher standard than the test calls for.

Looking at it another way. If the tires are actually capable of more load capacity, why wouldn't their manufacturer say so? Its legal and mentioned in FMVSS (standards). It can be seen as a fact with the ST235/80R16 LRE tires having three official load capacities at 80 PSI, 3420#, 3500# & 3520#.

Vehicle manufacturers can't use "phantom" numbers. Only established numbers can be used for vehicle certification.

There is a lot of confidential materials in every tire and the public is not going to have access to them because tire manufactures do not share their confidential information.

I don't know anything about litigation but I'd bet standardized tire information would be used over all others in a court of law.

jasin1 · 11-23-2020, 02:54 AM

[QUOTE=CWtheMan;422772]Yes, However without the approval of the vehicle manufacturer such replacements - by industry standards - would be a misapplication.

IMO, the vehicle manufacturer may not approve the use of ST235/85R16 tires is because the ST235/80R16 can be obtained with a LRF which is the same designated size. (Brands don't play a part in vehicle manufacturer OE tire selections because they are building to a load capacity).[/QUOTE

This is getting frustrating. Why should I have to be held to (minimum) standards of trailer manufacturers? Don’t they arguably build almost everything to the lowest cost standard? And how often do they update there standards? How often to they do engineering calculations on fifth wheel design? I am sure they have to approve every new model design change but do they spend the money to look at all options or just plug in new numbers to an old equation?
If I buy a boat with a weak spot in the hull and I reinforce it with better materials in that spot ,would I be held liable in a court of law if it sank for another reason?
I can see that you really know tires and I respect your opinion but why is there aftermarket wheels and tires and axles if you can’t replace with something “above” minimum specs?

There is a billion dollar aftermarket for accessories for cars and trucks and I almost never hear of any legal issues unless it’s a truck lifted 10” hitting a small car or other extreme modifications
And I do understand that they have to follow NHTSA guidlines but it does seem like rv manufacturing follows the razor thin adherence to these and if a consumer surpasses them I can’t see it being a problem.
I could be wrong but I’m getting frustrated

jasin1 · 11-23-2020, 03:01 AM

Quote:

Originally Posted by CWtheMan

Yes, However without the approval of the vehicle manufacturer such replacements - by industry standards - would be a misapplication.

IMO, the vehicle manufacturer may not approve the use of ST235/85R16 tires is because the ST235/80R16 can be obtained with a LRF which is the same designated size. (Brands don't play a part in vehicle manufacturer OE tire selections because they are building to a load capacity).

And I have to disagree (respectfully) didn’t Ford part ways with Firestone because of blowout issues? That certainly was “brands playing a part”

It just seems like rv manufacturing is not interested in the public perception of quality
Car manufacturing seems to care for the most part about this perception (real or not)

jasin1 · 11-23-2020, 03:11 AM

Quote:

Originally Posted by CWtheMan

Yes, However without the approval of the vehicle manufacturer such replacements - by industry standards - would be a misapplication.

IMO, the vehicle manufacturer may not approve the use of ST235/85R16 tires is because the ST235/80R16 can be obtained with a LRF which is the same designated size. (Brands don't play a part in vehicle manufacturer OE tire selections because they are building to a load capacity).

And lastly forgive me for dragging this out but..... is the line in the sand the tires? Is that what we can’t change no matter what? Pin boxes? Hitches? Disk brake conversions ? All these ok but not so much tires ?

Northofu1 · 11-23-2020, 05:34 AM

Good Morning Brian,
You might be just over-thinking this. If your trailer is over 3 yrs old and you feel that the manufacturer specified tires are a little to close to your limit, just go up 1 load rating.
Both my trailers were 2015's and on the TT I went from a LRC to LRD with Carlisle's, and on the 5er I went from a LRD to an LRE also Carlisle's. Both units handled fine.
Nothing is impervious to nails, screws and other road debris. I decided on Carlisle as their track record is good on TT's and lighter 5ers.

Good Luck to you.

CWtheMan · 11-23-2020, 06:03 AM

[QUOTE=bjasin1;422774]

Quote:

Originally Posted by CWtheMan

Yes, However without the approval of the vehicle manufacturer such replacements - by industry standards - would be a misapplication.

IMO, the vehicle manufacturer may not approve the use of ST235/85R16 tires is because the ST235/80R16 can be obtained with a LRF which is the same designated size. (Brands don't play a part in vehicle manufacturer OE tire selections because they are building to a load capacity).[/QUOTE

This is getting frustrating. Why should I have to be held to (minimum) standards of trailer manufacturers? Don’t they arguably build almost everything to the lowest cost standard? And how often do they update there standards? How often to they do engineering calculations on fifth wheel design? I am sure they have to approve every new model design change but do they spend the money to look at all options or just plug in new numbers to an old equation?

If I buy a boat with a weak spot in the hull and I reinforce it with better materials in that spot ,would I be held liable in a court of law if it sank for another reason?
I can see that you really know tires and I respect your opinion but why is there aftermarket wheels and tires and axles if you can’t replace with something “above” minimum specs?

There is a billion dollar aftermarket for accessories for cars and trucks and I almost never hear of any legal issues unless it’s a truck lifted 10” hitting a small car or other extreme modifications.

And I do understand that they have to follow NHTSA guidelines but it does seem like RV manufacturing follows the razor thin adherence to these and if a consumer surpasses them I can’t see it being a problem.
I could be wrong but I’m getting frustrated

The following is (in part) the directions given to the vehicle manufacturer for tire fitments.

FMVSS 571.120 paragraph S5.3.1 Tires. 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 for the GAWR.

Throughout the tire industry you will find a statement similar to this one from the Keystone owner’s manual. It’s a NHTSA mandate.

Tire Size: “To maintain tire safety, purchase new tires that are the same size as the vehicle’s original tires or another size recommended by the manufacturer. Look at the Tire and Loading Information label, or the sidewall of the tire you are replacing to find this information. If you have any doubt about the correct size to choose, consult with the tire dealer.”

chunker · 11-23-2020, 06:09 AM

Here's my take and sorry if I've stepped on toes. Owners have the responsibility to make the best decisions about what equipment they put on their vehickles based on the best information available. This thread has some good and some misinformation. For me in tires I'm not putting Trailer Kings on anything even if they were given to me. Well maybe in an emergency to let me get someplace where a good quality tire is available. I feel, just my opinion, that Sailuns are an anomaly in the sea of chinese crap that ends up in the USA. When I need tires for the trailer I don't care if TK junk has higher weight ratings by a few pounds, I'll get a better tire but pay attention to what load range and weight rating it has. If it meets the minimum and MY safety margin, on they go. To quote RV manufacturers "quality statements" about tires is almost ludicrous because nothing else they do has any real QC involved. For any trailer running gear, tires, wheels, bearing, brakes, etc., get the best you can and don't be too concerned about what Thor/Forest River/Winnebago/??? "recommends because you know their recommendations are based on their $$$ bottom line primarily.

Just my opinion to which I am entitled, so now off the soap box.

EDIT adding. I'll not engage any in tit-for-tat discussion on this.

CWtheMan · 11-23-2020, 06:11 AM

Quote:

Originally Posted by bjasin1

And lastly forgive me for dragging this out but..... is the line in the sand the tires? Is that what we can’t change no matter what? Pin boxes? Hitches? Disk brake conversions ? All these ok but not so much tires ?

Those items are not individually certified by the vehicle manufacturer. Wheels & tires are.

CWtheMan · 11-23-2020, 06:27 AM

Quote:

Originally Posted by chunker

Here's my take and sorry if I've stepped on toes. Owners have the responsibility to make the best decisions about what equipment they put on their vehickles based on the best information available. This thread has some good and some misinformation. For me in tires I'm not putting Trailer Kings on anything even if they were given to me. Well maybe in an emergency to let me get someplace where a good quality tire is available. I feel, just my opinion, that Sailuns are an anomaly in the sea of chinese crap that ends up in the USA. When I need tires for the trailer I don't care if TK junk has higher weight ratings by a few pounds, I'll get a better tire but pay attention to what load range and weight rating it has. If it meets the minimum and MY safety margin, on they go. To quote RV manufacturers "quality statements" about tires is almost ludicrous because nothing else they do has any real QC involved. For any trailer running gear, tires, wheels, bearing, brakes, etc., get the best you can and don't be too concerned about what Thor/Forest River/Winnebago/??? "recommends because you know their recommendations are based on their $$$ bottom line primarily.

Just my opinion to which I am entitled, so now off the soap box.

EDIT adding. I'll not engage any in tit-for-tat discussion on this.

You may not have any faith in vehicle manufacturer tire selections. In reality, they are the only ones authorized to select the OE tires on your vehicle.

Because tire Designated sizes and their load capacities are standardized, brands are not mentioned in any of the regulations & standards. Sometimes a manufacturer like Keystone may offer options by brand, otherwise you'll not see them. They are a personal choice by the consumer/owner at replacement time.

The selection of OE tires is supported in FMVSS and goes something like this. "At the time of first sale the tires on the vehicle MUST be the same designated size as those certified on the federal certification label." There is no name brand mentioned which gives the consumer the option of having the selling dealer swap brands as long as they are the same designated size.

jasin1 · 11-23-2020, 09:29 AM

Quote:

Originally Posted by CWtheMan

You may not have any faith in vehicle manufacturer tire selections. In reality, they are the only ones authorized to select the OE tires on your vehicle.

Because tire Designated sizes and their load capacities are standardized, brands are not mentioned in any of the regulations & standards. Sometimes a manufacturer like Keystone may offer options by brand, otherwise you'll not see them. They are a personal choice by the consumer/owner at replacement time.

The selection of OE tires is supported in FMVSS and goes something like this. "At the time of first sale the tires on the vehicle MUST be the same designated size as those certified on the federal certification label." There is no name brand mentioned which gives the consumer the option of having the selling dealer swap brands as long as they are the same designated size.

I respect your opinion and I’m going to make a decision soon. It reminds me of being against the law to remove a mattress tag. And you did say it pertains to the first sale so I understand the importance of letting a customer see what is spec’ed but I think it’s going overboard to say it can’t be above specs after the sale Maybe I misunderstood you but like the other member said Of all the things the manufacturer claims and says about the rig That this is the one thing that is carved in stone. It’s this kind of thinking that stifles new ideas imo But again I do respect what you have to say and thanks

travelin texans · 11-23-2020, 09:48 AM

Must curious???
If I install the next rating up in size or load from the OEM who enforces that I "must" do this or not to that in regards to tires.
Does RVIA or FMCA have a tire enforcement team ready at a moment's notice when receiving a call from a tire dealer that I asked for more tire than "must" be put on my rv?
Sorry! Not trying to be a smart ***!
But if you put more tire, not less, on your rv than recommended who really cares. I don't think it would void your warranty, shouldn't be an issue in court in case of an accident & surely will be an improvement over the crappy tires the manufacturer put on them to begin with.
Personally on my rv I'm putting the best heaviest rated tire I can afford regardless of what the manufacturer says "must" be replaced with.
I believe if you took a poll of rv insurance companies a big percentage of claims come from blowout damages, mostly due to the cheaper by the train car load crappy no name Chinese tires from the factory.

CWtheMan · 11-23-2020, 10:24 AM

Quote:

Originally Posted by travelin texans

Must curious???
If I install the next rating up in size or load from the OEM who enforces that I "must" do this or not to that in regards to tires.
Does RVIA or FMCA have a tire enforcement team ready at a moment's notice when receiving a call from a tire dealer that I asked for more tire than "must" be put on my rv?
Sorry! Not trying to be a smart ***!
But if you put more tire, not less, on your rv than recommended who really cares. I don't think it would void your warranty, shouldn't be an issue in court in case of an accident & surely will be an improvement over the crappy tires the manufacturer put on them to begin with.
Personally on my rv I'm putting the best heaviest rated tire I can afford regardless of what the manufacturer says "must" be replaced with.
I believe if you took a poll of rv insurance companies a big percentage of claims come from blowout damages, mostly due to the cheaper by the train car load crappy no name Chinese tires from the factory.

Load capacity is not a part of a tire's designated size. Therefore, ST235/80R16 LRE is the same designated size as ST235/80R16 LRG.

Look at the chart in the reference. All load ranges for a given designated size use the same load inflation chart.

https://fifthwheelst.com/documents/C...T-Modified.pdf

ladon67 · 11-03-2021, 02:13 AM

I'm new to the forum as I'm looking to purchase another 5er after being RVless for the last 5 or so years. I was reading through this thread and one of the suggestions popped out at me- replacing your trailer tires with LT tires and I thought "hmmmm...why not?" So I googled "ST tire" and found the website below with a GREAT explanation of the difference and why you would not want to use a light truck tire in a special trailer tire application!

https://www.prioritytire.com/blog/wh...bout-st-tires/

Below is a great website that I found when I was upgrading the rims and tires on my Ram 1500. You can put the tires you have mounted now and what you want to switch to and it will give you a pictorial as well as numerical display of the difference on your vehicle (235-80 R16 vs 235-85 R16)

https://tiresize.com/wheel-offset-calculator/

DISCLAIMER- as another poster on here said "I'm not going to go tit for tat..." I'm not trying to reopen a can of worms. Just figured I'd post those two websites for future readers and hopefully be a positive contributor to this great forum!!

rhagfo · 11-03-2021, 04:50 AM

Quote:

Originally Posted by ladon67

I'm new to the forum as I'm looking to purchase another 5er after being RVless for the last 5 or so years. I was reading through this thread and one of the suggestions popped out at me- replacing your trailer tires with LT tires and I thought "hmmmm...why not?" So I googled "ST tire" and found the website below with a GREAT explanation of the difference and why you would not want to use a light truck tire in a special trailer tire application!

https://www.prioritytire.com/blog/wh...bout-st-tires/

Below is a great website that I found when I was upgrading the rims and tires on my Ram 1500. You can put the tires you have mounted now and what you want to switch to and it will give you a pictorial as well as numerical display of the difference on your vehicle (235-80 R16 vs 235-85 R16)

https://tiresize.com/wheel-offset-calculator/

DISCLAIMER- as another poster on here said "I'm not going to go tit for tat..." I'm not trying to reopen a can of worms. Just figured I'd post those two websites for future readers and hopefully be a positive contributor to this great forum!!

Well our 2005 Sprinter Copper Canyon 5er GVWR of 12,260# came with OEM LT tires.

I don't buy the stiffer sidewall talk, I believe ST tires have a higher profit margin! Our 235/85-16 LT "ONLY" have a weight rating of 3,042# or 12,168# total, and a speed rating of 103 mph! That 103 mph speed rating, tells me they are well within load capacity at 65 to 70 mph.
Here are some comparison photos of ST tires to LT tires. Ours are Yokohama YK-HTX and the ST's are Carlisle.

ladon67 · 11-03-2021, 05:15 AM

Rhagfo- very interesting!!!

CWtheMan · 11-07-2021, 06:36 AM

Quote:

Originally Posted by ladon67

Rhagfo- very interesting!!!

When comparing different tire designs you have to pay careful attention to all of the specs. LT tires, on average, have 5/32" more tread depth than like sized ST tires.

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