Things to know about trailer tires

[Keisling]

Originally Posted by greytraveler

Not sure if I am making any sense but our new trailer has ST225/75R15/C and if I read them right the tire load is 2,000 meaning, what, four tires carry a 8,000 load. The GVWR on the rig is 9,100 so am I under rated to start?

Could be the tire is good for 2,125 perhaps . That is still only 8,500 and unless I am way off base I should be getting new tires a load range up.

Cheer, GT

You need to subtract your tongue weight when calculating how much is carried on each tire. That tongue weight is carried by the tow vehicle and supported by jacks when unhitched.

[leefl]

I just ordered 5 new Maxxis tires. 3 had a date code of just under a year old, the other two just under 18 months old. Of course I have no idea how these tires were stored, whether indoors or outdoors.

Having spent almost $600 (before installation) on new tires I hope they'll last well beyond the 8500 mile trip we'll be starting in 6 weeks

[Airdale]

The Maxxis 5 year warranty for ST tires starts on the date molded on the individual tire.

[leefl]

Originally Posted by Airdale

The Maxxis 5 year warranty for ST tires starts on the date molded on the individual tire.

Yes, unfortunately true. Had read that elsewhere.
TBH tire warranties are often not particularly meaningful in the first place, so I'm more concerned about whether they've been stressed by being stored outside than I am by the warranty coverage. Unfortunately it seems that it's fairly common to receive older tires.
I'm half wishing that I'd paid the extra $100 and got them from the local Discount Tire store, but there's no guarantee that the stock they got would be any newer

[youroo]

They say you can Request newer dated tires before buying,but I think it would be simular to telling the Lumber yard to deliver 50 12' 2x4's "All Straight"! Youroo!!

[MillerTime]

Originally Posted by youroo

They say you can Request newer dated tires before buying,but I think it would be simular to telling the Lumber yard to deliver 50 12' 2x4's "All Straight"! Youroo!!

I've sent "new" vehicle tires back to tire rack, when they sent me, year old tires. I never mounted them, and i called and they shipped me return stickers. They checked their stock (took a day or 2) but everything was the same for that brand and size.


So i called discount tire direct since they now showed my brand in stock, but hadn't a few days earlier. I told them the tires needed to be less than 6 months old. They shipped me tires that were about 3 or 4 weeks old.
Just tell them when you order. Tire dates are a big thing to me !

[youroo]

Originally Posted by MillerTime

I've sent "new" vehicle tires back to tire rack, when they sent me, year old tires. I never mounted them, and i called and they shipped me return stickers. They checked their stock (took a day or 2) but everything was the same for that brand and size.


So i called discount tire direct since they now showed my brand in stock, but hadn't a few days earlier. I told them the tires needed to be less than 6 months old. They shipped me tires that were about 3 or 4 weeks old.
Just tell them when you order. Tire dates are a big thing to me !

Agree,sounds like a good time to buy "Fresh Tire's" is Now! Youroo!!

[leefl]

Believe me, I specifically requested newer stock (bought from autopartsway online) but they obviously ignored me, or those were the newest they had (the 2 replacement tires they sent, after originally sending 2 of the wrong tires, were older than the other 3).
I'll contact them, but don't hold much hope for getting them to ship newer

[Iwannacamp]

Check out discount tire on eBay. I got a $100 instant coupon and free shipping and no tax. Win win. $60 to mount/balance at local DT.


Sent from my iPhone using Forest River Forums

[Tireman9]

Originally Posted by greytraveler

snip

Not sure if I am making any sense but our new trailer has ST225/75R15/C and if I read them right the tire load is 2,000 meaning, what, four tires carry a 8,000 load. The GVWR on the rig is 9,100 so am I under rated to start?

Could be the tire is good for 2,125 perhaps . That is still only 8,500 and unless I am way off base I should be getting new tires a load range up.

Cheer, GT

Not sure where you came up with the 2,000 load. I find that LR-C ST225/75R15 are rated for 2150# at 50 psi.
It is my understanding that many TT have axle ratings that are 10% lower that GVWR so your tires meet the requirements.

You need to check the "Max Load" number molded on your tire sidewall and to check the GAWR. While at it you should also get the real load on each axle so you know you are not overloading the axle or tires.

[Tireman9]

Originally Posted by Oaklevel

snip

My question that no one can seem to answer is how long have ST tires been out there my first two campers both 24' duel axle came with P rated tires from the factory......

ST type tires have been around for 20+ years

[Airdale]

Originally Posted by Oaklevel
snip

My question, that no one can seem to answer, is how long have ST tires been out there? My first two campers (both 24' duel axle) came with P rated tires from the factory.

Passenger tires are still used by some trailer manufacturers. I recently attended an “outdoorsman” show that featured a great many large bass boats on dual axle trailers. About 35% of those trailers were fitted with “P” tires. I did the math, all had been properly derated for trailer service.

[Airdale]

Tire load index

With new rules governing tariff taxation on foreign tires, specifically requiring most foreign manufacturers of ST tires to provide a speed rating on every tire’s sidewall, we are seeing them using a tire service description with a speed letter for the tire. Although the load index section of the service description is not the official load capacity measurement for ST and LT tires they are still allowed. Probably because someday that form of load capacity determination will be standardized for all DOT highway tires.

One of the shining problems with some ST tires is the fact that the Load Range system used for determining the tire’s load capacity is not always accurate without further explanations. The ST235/80R16E tires are, or have been, manufactured in three distinct load capacities, all identified as LRE. The actual load capacities can be 3420#, 3500# & 3520#, all at 80 PSI. The new ST tires with load index and speed letters will have a 123 load index for the 3420# tires and a 124 load index for the 3520# tires.

Nice to know information when your OE tires are really close to being maxed-out, and a need to know fact, when replacing 3520# tires that have been used on 7000# axles and you’re thinking about using a name brand with the 3420# tires which do not qualify for 7000# axles.

[ourjoyride]

Originally Posted by Airdale

Please don’t take this as a harsh answer. It’s just based on facts that people don’t like to accept.

For a long time know I’ve been doing the safety side of tires. I’ve been branded all kinds of bad and have even been banned from tire threads - sometimes - because of my harsh postings.

Tire dealers cannot over ride, trump, or any other way, do less than the vehicle manufacturer. Because? The vehicle manufacturer, in the eyes of the governing body (DOT) has sole authority for Original Equipment tire and rim fitments. They are required to put their (MINIMUM) selections along with recommended tire inflation pressures for them on the federal certification label and display it on your trailer.

Tire industry standards (aftermarket) consist of a set of standards from tire manufacturers, the Tire & Rim Association (TRA) and Rubber Manufacturers Association) RMA. They are very consistent and found in any tire manufacturer’s Standard Operating Procedures (SOP) manuals and PDF files found on the internet.

For a tire dealer or any other tire shop to change your trailer tires from one design to another is considered a misapplication. In fact, any change not recommended by your trailer manufacturer in the Owner’s Manual for your particular trailer is a misapplication. RV trailer tires do not have the same industry standards as the automotive industry with their pre-selected replacement lists and approved “plus sizing” procedures.

Why a trailer manufacturer selects and installs the tires on your trailer is immaterial. It was their decision to make within the guidelines provided by the governing body (DOT). None of the designs such as Passenger (P), Light Truck (LT), Special Trailer (ST), Hybrid - ties with a LT prefix marked “for trailer service only” or any of the wide range of medium to heavy duty truck/trailer tires are exempt. But, no matter what their design they are all installed in accordance with FMVSS guidelines. Not to be confused with guidelines for the trucking industry.

The bottom line. Once your drive off with your new or used trailer, it’s yours to do with as you see fit. I encourage you to be safe with everything including your tire selections. Below is a version of minimum industry standards. It’s from Michelin - hard to find them admitting they don’t control everything.

(Click on the tab "changing sizes or specs").


http://www.michelinman.com/US/en/help/how-to-choose-tires.html#tab-4

This seems like sound advice. Maybe you could help I'm wondering about tire rotation. I rotate my truck tires about every 6000 miles. Should I be doing that with my camper. Is there a known pattern I should follow?
It's a tandem axle and nitrogen filled tires.
Also I don't have nitrogen how do I top off my tires. Should I look for a hi end gage to check them? I don't like how much I lose when I check and don't want to top off with just air.

[TitanMike]

Originally Posted by ourjoyride

This seems like sound advice. Maybe you could help I'm wondering about tire rotation. I rotate my truck tires about every 6000 miles. Should I be doing that with my camper. Is there a known pattern I should follow?
It's a tandem axle and nitrogen filled tires.
Also I don't have nitrogen how do I top off my tires. Should I look for a hi end gage to check them? I don't like how much I lose when I check and don't want to top off with just air.

I'd rotate the trailer tires just like on a car using the "X" pattern. Better yet, rotate side to side one time and "X" the next. That way every tire will get to "ride" in every position and wear will be distributed evenly.

As for inflating a Nitrogen filled tire with Compressed Air? Go ahead. Air is 78% Nitrogen to begin with. Other elemental gases will eventually migrate through the tire's inner liner leaving Nitrogen behind.

While I was still "in the industry" I spoke with one of the largest suppliers of Nitrogen "generators" for the tire industry. He noted that a tire filled with Compressed Air would test at regular intervals with increasing percentages of Nitrogen. Stands to reason as the tire industry Nitrogen Generators are merely large membranes that allow gases other than Nitrogen to escape, holding back the Nitrogen to be used to inflate new tires. The process is the same in a tire, it just takes longer.

Have anyone ever noticed how a new tire might need some extra air added in the first year and after that it it doesn't need air as often? This is what happens as the Nitrogen concentration in a tire filled with Compressed Air increases.

In short, no need to buy a tank of compressed Nitrogen or for that matter any special "pressure gauge". Remember that 78%? It's clearly the majority of gas in ALL tires.

For those that have heard about "Compressed Air" being "Wet", a small silica gel compressed air dryer can be purchased for under $90 and installed on on a lock on tire inflator chuck with pigtail. Then add air from that Convenience Store compressor (or your own portable) by just through the dryer. Yes, "Air" contains about 1% water at sea level but after it passes through the desiccant, it's as dry as it gets.

[babock]

Originally Posted by TitanMike

Then add air from that Convenience Store compressor (or your own portable) by just through the dryer.

How many people actually use a convenience store air compressor anymore? I fill my tires at the beginning of a trip with my home compressor and after 20 feet from the compressor, goes through a drier. I use my compressor for painting so I need dry air.

[Airdale]

Originally Posted by ourjoyride

This seems like sound advice. Maybe you could help I'm wondering about tire rotation. I rotate my truck tires about every 6000 miles. Should I be doing that with my camper. Is there a known pattern I should follow?

Basically tire rotation is a product of the tire industry. My recommendation is to follow the requirements found in the tire warranty booklet and/or what is in the Vehicle owner's manual.

Personally I've put a lot of miles on RV trailers and single/dual axle boat trailers. I never found the need to rotate the tires. They are just follow along tires and get very similar wear front or back or side to side.

[babock]

If your tires are wearing evenly be it a trailer or a truck, you don't need to ever rotate tires.

The reason there are intervals for rotating tires...most people are too stupid to measure tire depth so if you just have them rotate at a specific interval...it all works out.

[fleabert]

[emoji179]

[Tireman9]

Originally Posted by TitanMike

I'd rotate the trailer tires just like on a car using the "X" pattern. Better yet, rotate side to side one time and "X" the next. That way every tire will get to "ride" in every position and wear will be distributed evenly.

As for inflating a Nitrogen filled tire with Compressed Air? Go ahead. Air is 78% Nitrogen to begin with. Other elemental gases will eventually migrate through the tire's inner liner leaving Nitrogen behind.

While I was still "in the industry" I spoke with one of the largest suppliers of Nitrogen "generators" for the tire industry. He noted that a tire filled with Compressed Air would test at regular intervals with increasing percentages of Nitrogen. Stands to reason as the tire industry Nitrogen Generators are merely large membranes that allow gases other than Nitrogen to escape, holding back the Nitrogen to be used to inflate new tires. The process is the same in a tire, it just takes longer.

Have anyone ever noticed how a new tire might need some extra air added in the first year and after that it it doesn't need air as often? This is what happens as the Nitrogen concentration in a tire filled with Compressed Air increases.

In short, no need to buy a tank of compressed Nitrogen or for that matter any special "pressure gauge". Remember that 78%? It's clearly the majority of gas in ALL tires.

For those that have heard about "Compressed Air" being "Wet", a small silica gel compressed air dryer can be purchased for under $90 and installed on on a lock on tire inflator chuck with pigtail. Then add air from that Convenience Store compressor (or your own portable) by just through the dryer. Yes, "Air" contains about 1% water at sea level but after it passes through the desiccant, it's as dry as it gets.

All new tires "grow" a bit. This means the internal volume increases so the pressure drops. When we test tires the test spec requires a controlled waiting period and re-inflation to take tire growth into account.