16" wheels

[Wingeezer]

Originally Posted by msmcv51

Would someone please answer my question. WHY the move from 15" wheels to 16" wheels???????

For my part I had just heard so many bad experiences with ST tires on various RV forums, (and also had a set of Marathons come apart on our last trailer,) that after reading a number of people's success stories an recommendations regarding LT tires from forum members whose opinions I respect, and needing new tires anyway, I decided now was the time to give them a try.

I was further encouraged by the fact that Jackson Centre have also decided to offer them now too.

The Michelin LT tires (and wheels) that I bought also have higher rated capacity than the ST tires that I removed, and should I ever need a replacement tire when on the road, should be fairly easily obtained.

Our local Airstream dealer suggested I opt for 15" Michelin LT tires, but they did not appear to match the load presented by our 10,000lb GVW trailer and so I was nervous about trying that and went with the 16" version which gives an added margin of capacity.

Those factors influenced my decision to switch to 16"LT tires.

Brian.

[SteveSueMac]

Originally Posted by msmcv51

Would someone please answer my question. WHY the move from 15" wheels to 16" wheels???????

Hi - it's a lot to sort through. I asked the same question a few months back. It can make your head spin!

Why do you ask? Are you thinking about it? Curious? Wondering if you can stay with your 15s?

[dkottum]

Originally Posted by polarlyse

Do most go with a plain steel wheel in 16" size or can we get away with the original spare in 15". I have 2 new spares and hate to replace them unless I have to.

Also, will a 16" spare fit in the front spare tire holder mounted behind the trailer
A-frame ?????

With the reliability of the 16" Michelins and the ability to remove a tandem axle flat tire and continue to drive for a replacement, it is not totally unreasonable to carry no spare, much less two. Depends on where and how much you travel.

But I kept the original 15" spare in the unlikely although possible event we may need it. It will fulfill its function of carrying us to a tire seller.

[jcanavera]

Originally Posted by dznf0g

Hmmm, try Tredit in Elkhart, IN. It's been 2 years since I got mine, but they shipped direct.

Yep I bought mine direct from Tredit in Elkhart two summers ago.

Jack

[polarlyse]

When we had our older AS 30'er it came with an extra wheel but no spare. I got a new tire and had the wheel sandblasted and painted. I kept it when we sold the trailer and the newer trailer also came with one. That's why I have 2 spares. One is mounted in a underneath carrier and one I carry in the truck. I have never needed to use one. I plan to mount my take-off GYM's on my son's flatbed trailer. Not as heavy as our AS and much newer than the ones he has on it now. Unfortunately the wheels will not fit. I'm glad to see you agree that the 15"er will make an OK spare at least for the time being. I may look for a steel wheel down the road and get a 16" spare. But, until then I should be OK to travel.

Thanks all, Keep up the good work

[switz]

Max pressure is 80psi for Load E tires.

SenDel also makes a galvanized steel wheel and a white painted steel wheel with similar load specifications to the T03-66655T wheel of 3,580 pounds @ 80psi.

Also, Andy at CanAm suggests 45psi for the 15" Michelin tires. I used that pressure on our 2013 25FB International Serenity without issue.

[CapriRacer]

Originally Posted by dkottum

Okay, many of us have upgraded to 16" Michelin LT tires from the original 15" GYM ST tires for reliability, and perhaps extra load capacity.

The question is, do we follow Airstream's recommendation for this tire upgrade (which is factory standard on some models and available as an option on others) of 80 psi (cold) or not? That is the maximum pressure printed on the sidewall.

Short answer: Use the maximum on the sidewall

Long answer: The way you have posed the question makes it unanswerable. What you are trying to achieve is a maximum of an 85% tire load (based on the load tables) and without knowing the actual loads on the tires you would be making a bunch of assumptions that may be unwarranted.

If you follow Airstreams recommended pressure (which also is the maximum on the sidewall) you are assuming that they have properly sized the tire - and we don't know that. It seems like a good assumption, since this is nominally an upgrade, but there may be situations where it isn't.

[Moflash]

It is hard to believe that some would spend the money for a Airstream trailer and be to frugal (cheap ) to buy a matching proper spare tire or forgo a spare tire at all .Wow I have seen it all

[dannydimitt]

Originally Posted by Moflash

It is hard to believe that some would spend the money for a Airstream trailer and be to frugal (cheap ) to buy a matching proper spare tire or forgo a spare tire at all .Wow I have seen it all

As chief tightwad and bottle washer , I resemble that remark !

as Ben Franklin one time opined "A penny saved is a penny earned "

[dkottum]

Moflash, many of us have decided the standard 15" is "proper" enough to supplement the highly reliable 16" Michelins. Why is it unproper? A good answer and I'll go buy one.

As for no spare, that's also a choice for local travel on a tandem axle Airstream I suppose. I don't do it, but I wouldn't condemn someone who does.

[polarlyse]

Now I know why I carry 2 spares. To loan one out of course !!!!!!

[Ridgerunner3]

Originally Posted by Moflash

It is hard to believe that some would spend the money for a Airstream trailer and be to frugal (cheap ) to buy a matching proper spare tire or forgo a spare tire at all .Wow I have seen it all

A person could carry out that same logic to many hardware upgrades for your Airstream. Each person draws a line somewhere and says I am not going to spend money on that upgrade. For me I spent money on a Propride hitch but would not spend the money on the 16" wheel upgrade. I decided that I would limit my tire / wheel budget to the 15 Michelin tires & not go the whole way with the 16" wheels. Every person has a different set of budget criteria and risk analysis. Just my 2 cents.

[jcanavera]

I bought a spare 16" wheel that is identical to the Airstream supplied 15" spare. I'm watching for a sale on LT tires locally. Since this new LT tire probably never see the ground much if any, I'm not going to spend as much for something that I consider a throw away after several years of sitting under the trailer.

Thinking about it I really pushed the envelope on my 15" spare. It's the original and has been on the ground once...but only to hold the weight of the trailer as it sat in the drive as I was doing tire swaps when replacing the original ST's.

Jack

[rodsterinfl]

The question is, do we follow Airstream's recommendation for this tire upgrade (which is factory standard on some models and available as an option on others) of 80 psi (cold) or not? That is the maximum pressure printed on the sidewall.

I was unable to find any information on truck tires and load; however, I did find several informational articles on trailer tires- how that it is critical that ST tires be run at maximum pressure due to thicker sidewall heat generation. That is not the case with LTX tires.

My posting of the LTX tire chart was not to create an issue but I thought it would be helpful consideration. I am still trying to find information about truck tires and loading. I know that on my truck I had to take some pressure off so I went to 60psi on the front, which was what the installer originally inflated them to. In the case of my truck, the placard says D rated 50psi and the sidewall says 80psi. The local Ford service manager said to inflate EITHER D or E rated tires at 50 psi on my vehicle regardless of sidewall rating- just sayin. I spoke to him Friday. As for my trailer LTX tires, I am still researching this.

I believe that there is merit in the chart. Michelin has an RV chart for the Rib tire. Looking at that tire chart, the load information is similar to the MS/2 in matching load to inflation. Why would the charts be published if everyone were to use maximum pressure when using the tire- for safety or other issues?

Here is an informational post from a truck forum poster I found, an 18 year tire company veteran, who interrupted their forum's very long thread on the same issue only related to trucks and carrying loads:

"I worked for Michelin Tire Corporation for 7 years and Yokohama Tire Corporation for 11 years. I have given numerous tire seminars on tire maintenance and especially how to determine the correct tire pressures. So here goes.
The pressure on the sidewall of the tire is the maximum pressure at the published load at approximately 55 mph. (The speed can vary somewhat but it is not important for our discussion). The air pressure is required to support the load that the tire must carry in such a manner that the tire flexes at the designed place on the sidewall of the tire. If the load on the tire changes then the air pressure should change accordingly to keep the tire flexing at the proper place. The reason for correct air pressure is to prevent the tire from overheating. It was put together with heat and it will come apart the same way. An under inflated tire will eventually self destruct due to excessive heat build up. An over inflated tire will ride harshly and be more likely to burst upon impact. Sorry for the long explanation but here is the bottom line. To determine the correct air pressure, check the pressure when the tire is cold. Run the tire for several miles at highway speed. Stop and immediately check the air pressure in the tire. It should be higher than when cold but no more than 10% higher. Now here is the hard to believe part. If the pressure is more than 10% higher you must ADD AIR and test again. For example if you start with 50 psi cold. If the pressure is 60 when hot, you have exceeded the (10%) in this case, 55 psi maximum safe heat build up pressure. You must ADD AIR. In this case I would add 5 psi which would take the tire to 65 psi when hot. After you run the tire again you will find the pressure to actually drop because the tire will run cooler. The heat build up causes the tire pressure to increase when under inflated.
On the other hand, if the 50 psi cold pressure does not change when hot. You have more air than needed. You can remove 5 psi or so and test again when they return to cold. Like the next trip you take. So a fully loaded rig will require more air in the tires than one with empty tanks and a light load on board. Always error on the side of over inflation. Thus the maximum sidewall pressure indicated on the tire is usually used. It usually is more than needed. Each axle has its own requirement based upon the load on that axle."

LandcruiserPhil

I posted his words here because it, to me, answered many questions and clarified some responses. The main point is that we all are switching to 16" LTX tires for reliability and safety over that of the ST tires available. That will happen. As I stated earlier my only purpose was to post information from my quest on finding the optimum pressure since I was dealing with it on the tow vehicle too. For the record, I have learned more about tire pressure than I thought possible for a lay camper! No worries.

[dkottum]

Boy it's hard to get a straight answer on the correct tire pressure for the Michelin 16" XL upgrade (or standard on EB models) for Airstream.

Airstream has 80 psi on their trailer placard for those models where the tire is standard, their Service Center at the factory recommends 80 psi (I was there last week and asked them directly, the Service Manager and the tech airing my tires); here it's yes, no, maybe, but, and if. Or I know someone who . . .

I'll stay with the 80 psi.

[Howard L.]

((((To determine the correct air pressure, check the pressure when the tire is cold. Run the tire for several miles at highway speed. Stop and immediately check the air pressure in the tire. It should be higher than when cold but no more than 10% higher. Now here is the hard to believe part. If the pressure is more than 10% higher you must ADD AIR and test again. For example if you start with 50 psi cold. If the pressure is 60 when hot, you have exceeded the (10%) in this case, 55 psi maximum safe heat build up pressure. You must ADD AIR. In this case I would add 5 psi which would take the tire to 65 psi when hot. After you run the tire again you will find the pressure to actually drop because the tire will run cooler. ))))

There is much great info on this thread. After reading it the first time, I became convinced I should, and actually did, take the GYMs off our new 30 flying cloud and install load E tires. 15 inch trailer tires, not 16" LTs but 10 ply, 80 # tires just the same. But there are also some posts that are confusing and misleading. I believe the above statement was made from a base of knowledge. And, in general terms may well be correct--in a way, makes perfect sense (higher pressure = cooler running.). However, I know from my own test it will not always be that simple. My test: 80 psi on new Maxxis when cold. Stop and test pressure 2 hours later while pulling trailer at 65 mph on Texas interstate 10 with outside air temp 102. Tire pressure 90 psi. That breaks the 10% rule and would require cold inflation above the cold max if above instructions were followed.

For a softer ride, or better braking (if you believe less pressure achieves that), stick with the GYMs or any other D tire and fill them to 65 psi (check your weights, maybe you can drop down to a C rated tire). If you want a tire Built to perform well with weights way in excess of of our Airstreams, and you want that overkill for safety reasons, put the Es on and air them up to E @ 80psi. If you just have to do something different, then drop to 75. Don't get tied up with what the auto manufactures do, as explained earlier, they will lower the psi door sticker so that the max chart weight the tires will carry will match the trucks axle and not exceed it. We should not care about that. We're not going to exceed the axle weight (well except some of the older 3500# axles) or the 10 ply tire weight. We just want the largest safety margin available and the more we lower the tire pressure the less of that we have and the more the tire heats up. Rocket Science 101.

[jcanavera]

One of the things that doesn't get too much mention is speed. One of the things I was taught is that the faster you go, the more heat you build up due to the flexing of the tire. The faster the rotation, the more flexing that occurs. Some tires dissipate heat faster than others or have compounds that can handle higher temperatures. Supposedly that is one reason why if you exceed the speed rating of a tire, the more likely you are in danger of failure due to heat build up.

Jack

[Moflash]

I have put 8000 miles or more on 16 LT's I run 70lbs.I have checked the internal temps real time at 80psi and at 70psi the difference at hwy speeds at various outside temps up to 103f is negligible.For me 70psi is the number.
My background 39 years in the automobile business so I have see a few tires fail and survive.

I also have a matching size spare tire on all my vehicles including my Airstream
for three reasons

A.The 15 inch ST tire is 1.1 inch smaller in diameter than the 16 LT

B.Why would I keep a tire for a spare that has a high failure rate? Not

C.Just knowing that I did something half a**ed would drive me crazy as my life revolves around Murphy's Law.

I also believe tires die in five years and must be replaced even if they look new on the outside they are dry rotted inside.I have seen it over and over again.

[rodsterinfl]

However, I know from my own test it will not always be that simple. My test: 80 psi on new Maxxis when cold. Stop and test pressure 2 hours later while pulling trailer at 65 mph on Texas interstate 10 with outside air temp 102. Tire pressure 90 psi. That breaks the 10% rule and would require cold inflation above the cold max if above instructions were followed. For a softer ride, or better braking (if you believe less pressure achieves that), stick with the GYMs or any other D tire and fill them to 65 psi (check your weights, maybe you can drop down to a C rated tire).

Hey Howard, what Phil shared about testing tire pressure and also sidewall arching at a certain point related to the weight is, in my opinion a great description of dialing in the perfect pressure for the load being carried. That does not mean you can use any load range tire for lower pressure. What makes it even better is how a TPMS can make this easy- one that reads PSI and temp. I totally understand DKottum and others' concerns for doing what is best. I do not run any tires at maximum pressure personally; however, I now understand why ST tires are to be maxed out. I plan to try what Phil prescribed using my TPMS with my CAT scale readings with a 20% leeway to start.

[rodsterinfl]

Hello 16" wheel peeps. As I previously mentioned I got the sendel wheels. Today I ordered the ms/2 tires but in discussing the install with the manager at SAMs he said they could not mount them on the wheel with warranty if it was going on a trailer. I told him the factory was using them now on their 16" wheel option but he said without an official statement he could not mount them on the wheels. He said to go ahead with the order and in the meantime he would check on it. The tires went on sale today. Any ideas? I looked on the Internet for something from Airstream.