Tires & speed

[Gene Masse]

A while back on this or one of the Casita forums there was some mention that the 13" tires on FG campers have a 65 MPH max rating. I can't find that written on mine anywhere. Does anyone have any info on that? I don't plan on going over 65 anyway just to get better mileage but am wondering limitations there really are.

[Carol H]

If the tires are marked ST then they are only rated to 65 mph.

[Gene Masse]

To my knowledge the ST is what designates them as trailer tires. "Special Trailer" or something like that. Nothing to do with speed.
This web site has some info but I wasn't sure how to interpret it. I called them and was told the "H" on another spot on the tire says 89MPH, but there was another letter there that confused the person I was talking to.
It's hard to believe that these tires wouldn't be rated faster than 65 considering today's speed limits.

Tire Tech Information - How to Read Speed Rating, Load Index & Service Descriptions

[Carol H]

Here you go Gene.

Quote "All "ST" tires have a maximum speed rating of 65 mph."

[baron100]

Both Maxxis and Goodyear have indicated to me that ST tires can be inflated an additional 10 psi to accommodate speeds up to 75 mph. There are certain important caveats that apply

I am not advocating to the forum that everyone should do this. RV safety studies have indicated that trailers are often overloaded for the load range tires they are using or under inflated. Increase in speed over 65 mph in these conditions is a recipe for disaster.

A Goodyear Service Bulletin is attached.


http://casitaadventures.smugmug.com/...T1-Large-L.jpg

http://casitaadventures.smugmug.com/...t2-Large-L.jpg

[Donna D.]

Frankly, I travel at the speed where I get the best fuel mileage considering tug/tow/environmental conditions. For my combination that's usually 57 mph. I have NO desire to get somewhere fast, where it costs me $$ in fuel (and stress). My trailer is traveling on ST205/75 R15 Marathons inflated to 50 PSI. YMMV

[baron100]

Originally Posted by Donna D.

Frankly, I travel at the speed where I get the best fuel mileage considering tug/tow/environmental conditions. For my combination that's usually 57 mph. I have NO desire to get somewhere fast, where it costs me $$ in fuel (and stress). My trailer is traveling on ST205/75 R15 Marathons inflated to 50 PSI. YMMV

Donna, I am not Frankly, but that is a very wise speed philosophy.

[Donna D.]

Rob, there's a bunch of "Frankly's" that hang out here... and aren't we glad Make a great memory every single time you pull your all molded towable someplace

[mike_bc]

Originally Posted by Donna D.

Frankly, I travel at the speed where I get the best fuel mileage considering tug/tow/environmental conditions.

Agreed Donna.

[/QUOTE]My trailer is traveling on ST205/75 R15 Marathons inflated to 50 PSI. YMMV[/QUOTE]

I am confused. I just finished writing in another response that I run at 35 psi and I have the same tires as you have. The trailer manufacturer recommends this and the tread wear is 80% remaining after 5 years so I'm under the assumption 35psi working for me.

May I ask why 50 psi?

[Carol H]

Originally Posted by mike_bc

Agreed Donna.

Originally Posted by Donna D.

My trailer is traveling on ST205/75 R15 Marathons inflated to 50 PSI. YMMV

Originally Posted by mike_bc

I am confused. I just finished writing in another response that I run at 35 psi and I have the same tires as you have. The trailer manufacturer recommends this and the tread wear is 80% remaining after 5 years so I'm under the assumption 35psi working for me.

May I ask why 50 psi?

Mike I am not Donna, but you need to keep in mind that that the trailer manufacture doesnt actually make the tires. Whats more important is what the tire manufacture says I also inflate to the max 50 PSI. The general guidelines given regarding trailer tires is that you need to inflate trailer tires to their max psi when cold as that is the only way to get them to their max load rating. I believe the max load rating on the tires in question is 1,820 @ 50psi. So if trailer is close to that weight on an any of its axles it needs to be inflated to that.

My old Scamp had a sticker above the wheels that said not to inflate tires over ex so many PSI as well..... when I first got the trailer I changed the tires and the guys at the tire store took the sticker off after asking me what the trailer actually weighed loaded and said that it was dangerous for Scamp to put such a sticker on the trailer.

[floyd]

My trailer is traveling on ST205/75 R15 Marathons inflated to 50 PSI. YMMV

I am confused. I just finished writing in another response that I run at 35 psi and I have the same tires as you have. The trailer manufacturer recommends this and the tread wear is 80% remaining after 5 years so I'm under the assumption 35psi working for me.

May I ask why 50 psi?

VVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV

It must be.... especially if you plan to use the "Logan's Run" replacement plan.
Since you have used less than 2/32", you have not yet worn them to the point of best efficiency. The next 2/32" should wear even slower, but should also start to dispel some of your confusion.
Your trailer has two axles while the Scamp 16 has only one.This makes a difference eventhough your trailer is a bit on the "chubby" side.

[Carol H]

Goodyear actually has a pretty good section re trailer tires on their website.

[steve dunham]

When I purchased my Hankook RA08 tires for my 16 ft. Scamp, my tire dealer told me they had inflated my new tires to 65 Lbs PSI ( MAX air pressure) He told me that tires used on trailers should be run at max air pressure. Being a doubting soul, I called Hankook and asked them what pressure I should run the tires at and got the same answer " Max air pressure listed on the tire". I do not pretend to be a tire expert but I would believe a large tire retailer and the tire manufacturer should know something about tires

[RogerDat]

I am confused. I just finished writing in another response that I run at 35 psi and I have the same tires as you have. The trailer manufacturer recommends this and the tread wear is 80% remaining after 5 years so I'm under the assumption 35psi working for me.

May I ask why 50 psi?

Air pressure is a direct factor in the load rating of a tire. Same tire at different PSI can be rated at different load capacity. D load rated tire at 50 psi may only be a C rating at 35 psi.

Single axle having two tires to carry load, double axle has 4, given twice as many tires without twice the weight don't need the full load capacitiy of the tire.

Heat and age which break down the tire internally are what kills most camper tires, not tread wear. So many people run at max pressure manufacture states for the tire. Higher psi = less heat + greater bruise resistance from pot holes + stiffer sidewalls for less sway. At expense of somewhat stiffer ride for trailer.

Logans Run is reference to a sci-fi movie where everyone is killed at a certain age. Some people replace their tires at a certain age rather than based on tread.

[Carol H]

Originally Posted by RogerDat

Logans Run is reference to a sci-fi movie where everyone is killed at a certain age. Some people replace their tires at a certain age rather than based on tread.

What would be me for one I learned the hard way twice now using two different brands of tires that tire failure at the worst possible time and location that it just isnt worth running them for more than 4 years. Bit of pain to find yourself in a location where you dont have a lot of options as to whats available to replacing them with or what your going to pay for them My own experience suggests that regardless of how much tread is left or what the tire looks like on the outside what the so called tire experts say in regards to age of tires & running them for more than 4 or 5 years on a trailer may have more than a little truth to it.

Edit note: I took the leisurely coastal road home from the Bandon meet but I had another party who was took the I5 home report that they saw two fiberglass trailers from the meet with blow outs on the I5 on the Sunday.

[floyd]

Originally Posted by Carol H

What would be me for one I learned the hard way twice now using two different brands of tires that tire failure at the worst possible time and location that it just isnt worth running them for more than 4 years. Bit of pain to find yourself in a location where you dont have a lot of options as to whats available to replacing them with or what your going to pay for them My own experience suggests that regardless of how much tread is left or what the tire looks like on the outside what the so called tire experts say in regards to age of tires & running them for more than 4 or 5 years on a trailer may have more than a little truth to it.

Edit note: I took the leisurely coastal road home from the Bandon meet but I had another party who was took the I5 home report that they saw two fiberglass trailers from the meet with blow outs on the I5 on the Sunday.

Were the two tire failures "blow outs"?
Were the failed tires each more than 4 years old? Every flat is not a "blow out", nor is every "blow-out" the result of age.
How about the two on the I-5?

Visual inspection with a trained eye and pressure maintenance are more effective than a calendar in preventing tire failure.
It doesn't bother me, if someone chooses to buy tires on schedule,but it does bother me that some seem to think that doing so will exempt them from tire failure or relieve them from the responsibility of regular tire maintenance.

My car dolly was recently sold with tires in good shape with over twenty years of use (mostly sitting). My Eight year old Scamp has four years on the second set of tires. It may soon actually be getting it's third set, but it will be tread and carcass condition which determines replacement.

As much as we use our trailer (60,000 miles so far) it's not likely that any tire on it will die of old age, or be discarded simply due to time.

BTW...The recommendations from reputable "experts" who advocate the "Logan's Run" method for tire replacement generally range from 6-10 years.

[Carol H]

Originally Posted by floyd

It doesn't bother me, if someone chooses to buy tires on schedule,but it does bother me that some seem to think that doing so will exempt them from tire failure or relieve them from the responsibility of regular tire maintenance.

BTW...The recommendations from reputable "experts" who advocate the "Logan's Run" method for tire replacement generally range from 6-10 years.

Floyd all I can tell you the two trailers on the I5 were that they were both apparently full blow outs. In one of the cases it was noted there wasn't a great deal left of the tire, appeared to a 3rd party to be a total delamination of the tire.

I appreciate that you probable have a lot more experience than I at looking at a tire to see if it has issues or not but I do my best to try and maintain my tires. I have them balanced by the local tire store and prior to and during every trip the pressure is checked often and I run them at max. In the case of both the 4 year old tire failures I have had, neither where full blow outs while driving and the only reason they were not was that I noticed during my routine tire and hub check while getting gas, that the tire was starting to separate. In both situations the tire shops I went to for replacements took a look at the tire tread and wear and indicated they could see anything out of line in regards to wear and in both cases suggested it was the tire age factor. One of the parties suggested that I needed to take into consideration that even though the tires had only been on the trailer for 4 years they may be a few years older than that as its not unheard for a tire to sit in a shop for sometime prior to being sold. I actually did attempt once to figure out how one goes about reading the expiry date on a tire but gave up.

I also dont believe for a minute that by changing my tires out at 4 years that it will exempt me from tire failure or maintenance- my only hope in changing them out at 4 years is that it will reduce the likelihood of them falling apart due to age while driving down the highway - now that I know for a fact age is a common factor in trailer tire failures. Just one less possible blow out cause to worry about.

As long as people understand that a tires age does become a factor in its reliability and I am not so sure everyone does know that - I know I sure the heck didn't prior to the first tire failure - then its an individual choose as to how long they want to push it and are comfortable using them.

The tire store I last visited had a lengthy paper that was actually written by a major brand many of us use that indicated the age deterioration factor started at 5 years on trailer tires. This website indicates that 3 to 5 years is the projected life of a trailer tire, here is another that suggest 5 to 7 years.

[floyd]

Originally Posted by Carol H

Floyd all I can tell you the two trailers on the I5 were they were both apparently full blow outs. In one of the cases it was noted there wasn't a great deal left of the tire, appeared to a 3rd party to be a total delamination of the tire.

I appreciate that you probable have a lot more experience than I at looking at a tire to see if it has issues or not but I do my best to try and maintain my tires. I have them balanced by the local tire store and prior to and during every trip the pressure is checked often and I run them at max. In the case of both the 4 year old tire failures I have had, neither where full blow outs while driving and the only reason they were not was that I noticed during my routine tire and hub check while getting gas, that the tire was starting to separate. In both situations the tire shops I went to for replacements took a look at the tire tread and wear and indicated they could see anything out of line in regards to wear and in both cases suggested it was the tire age factor. One of the parties suggested that I needed to take into consideration that even though the tires had only been on the trailer for 4 years they may be a few years older than that as its not unheard for a tire to sit in a shop for sometime prior to being sold. I actually did attempt once to figure out how one goes about reading the expiry date on a tire but gave up.

I also dont believe for a minute that by changing my tires out at 4 years that it will exempt me from tire failure or maintenance- my only hope in changing them out at 4 years is that it will reduce the likelihood of them falling apart due to age while driving down the highway - now that I know for a fact age is a common factor in trailer tire failures. Just one less possible blow out cause to worry about.

As long as people understand that a tires age does become a factor in its reliability and I am not so sure everyone does know that - I know I sure the heck didn't prior to the first tire failure - then its an individual choose as to how long they want to push it and are comfortable using them.

The tire store I last visited had a lengthy paper that was actually written by a major brand many of us use that indicated the age deterioration factor started at 5 years on trailer tires. This website indicates that 3 to 5 years is the projected life of a trailer tire, here is another that suggest 5 to 7 years.

If I were selling tires, I would give them the shortest projected life span that I could without losing sales to my competition! Still true... as a tire ages, it becomes ever more likely to show signs of deterioration.
While internal manufacturing defects can manifest themselves suddenly, the normal effects of heat and age will show externally.
Underinflation and overloading can also precipitate tire failure without the warnings properly associated with age.
I understand the futility of trying to dispel hard doctrine, so I am only trying to mitigate it's effects back to age of sound reason.
Truth be told, my tires generally get replaced before reaching the wear indicators or becoming superanuated, and I religiously change my oil more often than necessary...
Heck, life is easier with some degree of conformity to settled doctrine.

[RogerDat]

Manufacture date is 4 digit code week number and year. So 3509 would be 35th week of 2009. Code stamped inside circle or oval following DOT, typically on only one side of tire which may not be the side facing out.

So many variables go into tire aging, how maintained, how often used, how hard they are used, climate, how stored.

How much "reserve" load capacity is also a big factor. If tire strength is reduced by 25% due to age and one has more than 25% surplus might be OK if not....

With the single axle Scamps, I would think it might be less likely that two tires will have as much surplus load capacity on a 16ft as one might have on a 13ft unless one purchased tires taking that into account and paid a premium to get extra load capacity. Of course some of that depends on axle/hub/tire size which can vary a lot with mods.

The cheap Wally world tires that PO put on my 13 have just a little over 25% surplus capacity. I could hit 40% or better surplus capacity if I bought some of the good quality tires that others are using.

[Bob Miller]

Visual Insection with a "Trained Eye" sound like good advice, but where does someone find that eye.... From my own experiences with mini motorhomes, those eyes seem hard to find.....

I can't even hope to remember the number of stories I heard about sudden tire failures on the road, many occuring at as soon as 5 years of tire age. And, unless you bought new tires yourself, you don't have a clue as to how previous owners cared for the existing tires.

Sooooo... unless I put the tires on myself, I opt to believe that the worst case of care was taken and routinely toss tires at about 5 years regardless of appearance. The cost of a blowput on the road can be huge, both for another tire, as well as the potential damage to your rig.

BTW: A blow-out on the road, is like landing an airplane with the wheels up, it can ruin an otherwise perfectly good day.....