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Gene Masse 07-25-2012 10:27 AM

Tires & speed
 
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 07-25-2012 10:46 AM

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

Gene Masse 07-25-2012 11:32 AM

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 07-25-2012 11:40 AM

Here you go Gene.

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

baron100 07-25-2012 03:06 PM

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. 07-25-2012 06:27 PM

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 07-25-2012 07:05 PM

Quote:

Originally Posted by Donna D. (Post 323485)
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.:thumb

Donna D. 07-25-2012 09:20 PM

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

mike_bc 07-27-2012 07:56 AM

Quote:

Originally Posted by Donna D. (Post 323485)
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. :confused:

May I ask why 50 psi?

Carol H 07-27-2012 09:38 AM

Quote:

Originally Posted by mike_bc (Post 323826)
Agreed Donna.

Quote:

Originally Posted by Donna D. (Post 323485)
My trailer is traveling on ST205/75 R15 Marathons inflated to 50 PSI. YMMV

Quote:

Originally Posted by mike_bc (Post 323826)
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. :confused:

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 07-27-2012 09:53 AM

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. :confused:

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 07-27-2012 10:11 AM

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

steve dunham 07-27-2012 12:48 PM

Tire pressure
 
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 07-27-2012 12:54 PM

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. :confused:

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.


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