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Inland RV Center, In · 03-21-2013, 07:50 AM

Quote:

Originally Posted by HeadWest

Hi Andy, any recommendations on how to determine tire pressure that won't beat the trailer to pieces nor lead to tire failures? I have a new 28 International being built nest month with the 16" wheel/Michelin tire package. I'm sure the sticker from the factory will say 80PSI like others have reported. At 80, it can't be a smooth ride.

80 PSI for "E" tires????

Lets all strive to beat up the trailers, quickly.

That is fantastic for repair shops.

The tire pressure to use, to me, is a function of the load.

80 PSI is the maximum for "E" tires as well as for the steel wheels.

What will happen when hot weather is here, and that tire pressure increases?

A "maximum" rating doesn't mean that 's what should be used. Maximum means "don't exceed".

My opinion for "E" tires, is to use no more than 70 PSI. If that's not enough to carry the pay load, then perhaps the pay load should be decreased, but always maintain 'full" water.

The other interesting thing of late is "lets use "E" tires at 80 PSI".

But, do those folks typically have the running gear balanced or install Centramatics?

Heck no, that's a waste of money.

WOW!!!

Guess it all depends on personal choice, once again.

Andy

woodfox45 · 03-21-2013, 09:14 AM

Andy ; I have been watching this page on tires all winter and I'm still not convinced E rated tires are necessary but hearing all the failures of GYM's has me wondering what to do . I have a 1985 29' Sovereign and my GYM's are 4 yrs old . I can't find a 15" st tire US made from any tire mfg. I always keep my tires covered when in storage and they still look good but I don't trust them because of their age . I live in Ohio so we don't travel in the winter but I want to replace them this spring . I have herd some use a XL or extra load tire but I'm not convinced that is the way to go either . i do have centramatics that I purchased from you last year . I too don't want to shake my trailer apart with 80lb. psi but the cost between 15" and 16" is about the same if I buy new wheels . What would you do if you were me ? I value your opinion very much . Les Grace

CapriRacer · 03-21-2013, 12:15 PM

Quote:

Originally Posted by woodfox45

Andy ; I have been watching this page on tires all winter and I'm still not convinced E rated tires are necessary but hearing all the failures of GYM's has me wondering what to do . I have a 1985 29' Sovereign and my GYM's are 4 yrs old . I can't find a 15" st tire US made from any tire mfg. I always keep my tires covered when in storage and they still look good but I don't trust them because of their age . I live in Ohio so we don't travel in the winter but I want to replace them this spring . I have herd some use a XL or extra load tire but I'm not convinced that is the way to go either . i do have centramatics that I purchased from you last year . I too don't want to shake my trailer apart with 80lb. psi but the cost between 15" and 16" is about the same if I buy new wheels . What would you do if you were me ? I value your opinion very much . Les Grace

You didn't ask for my opinion, but here it is anyway:

First, is I don't think the issue of the additional inflation pressure is as big a difference as people make it out to be - in particular the difference between breaking and not breaking stuff in or attached to the trailer.

Second, If you have an ST225/75R15 Load Range D, then you have to be aware that a P235/75R15 XL has 555# less load carrying capacity (per tire). This might be an issue, so this has to be done very carefully.

Third, I'm a fan of going larger when it comes to trailers and tires. I like the idea of going from an ST225/75R15 Load Range D to an LT225/75R16 Load Range D (or E, but at 65 psi.), but the clearance has to be checked.

So without any additional info, I would advise you to go for the 16" option.

**jcanavera** · 03-21-2013, 01:10 PM

Quote:

Originally Posted by CapriRacer

You didn't ask for my opinion, but here it is anyway:

First, is I don't think the issue of the additional inflation pressure is as big a difference as people make it out to be - in particular the difference between breaking and not breaking stuff in or attached to the trailer.

Second, If you have an ST225/75R15 Load Range D, then you have to be aware that a P235/75R15 XL has 555# less load carrying capacity (per tire). This might be an issue, so this has to be done very carefully.

Third, I'm a fan of going larger when it comes to trailers and tires. I like the idea of going from an ST225/75R15 Load Range D to an LT225/75R16 Load Range D (or E, but at 65 psi.), but the clearance has to be checked.

So without any additional info, I would advise you to go for the 16" option.

The dangers of under inflation are much greater than over. The reality is that most folks don't have individual wheel weights much less axle weights. I was fortunate to have the opportunity to weigh my Safari in 2001 so I know what my average food and camping gear weighs. The other side of the equation is the fact that we are using LT tires in a tandem axle arrangements. Not the same as a typical truck arrangement.

With all this in mind no one really takes this type of use into account in inflation tables. As long as my wheels are rated correctly, carrying 80 psi on my heavy slide out Classic leaves me a lot more room for margin. I'd rather not be so exact that a cool day, an altitude change, or a bad estimation on load leave me in an under inflation state.

Jack

Phoenix · 03-21-2013, 02:05 PM

We have 16-inch wheels and Michelin XPS Ribs (225/75x16). Wheels and tires are balanced, and we have Centramatics. We run 80 psi, the maximum printed on the sidewalls.

I have ridden in our single-axle, 19-foot Bambi; and the ride is similar to our 2008 Tundra CrewMax on smooth roads at highway speeds, and a little more boat-like over irregular surfaces. However, the ride is not jarring, and it is not significantly different at 65 and 72 psi.

Also, I will not consider running lower pressures on our single axle Airstream in southwest desert areas; although, I might consider it, if we had multiple axles and lower tire loads with the same tires.

Gene · 03-21-2013, 07:55 PM

When we ran 68 lbs. in Michelin LR E 16" tires, the tread wear showed them slightly underinflated—that is wear was slightly greater towards the sides and slightly less at the center. Since we went to 72 lbs., wear has been even.

The tables are great to make an initial decision, but in the end the tires will tell you what they like.

Gene

KYAirstream · 03-21-2013, 08:06 PM

Do the centramatics for 15" wheels work on the 16" wheels? I didn't see them for 16".

SteveH · 03-21-2013, 08:11 PM

Quote:

Originally Posted by KYAirstream

Do the centramatics for 15" wheels work on the 16" wheels? I didn't see them for 16".

I have them on our trailer with 16" wheels/tires, but how would you know if they are really doing anything?

Inland RV Center, In · 03-21-2013, 08:13 PM

Quote:

Originally Posted by KYAirstream

Do the centramatics for 15" wheels work on the 16" wheels? I didn't see them for 16".

Yes they do, as long as there is a 10 inch flat spot on the back side of the wheels.

Andy

Inland RV Center, In · 03-21-2013, 08:41 PM

Quote:

Originally Posted by SteveH

I have them on our trailer with 16" wheels/tires, but how would you know if they are really doing anything?

Real easy.

Does stuff stay put in the trailer, and what kind of tire wear do you have, or not have.

Andy

Phoenix · 03-21-2013, 10:17 PM

Centramatics fit 16-inch, Sendel T02's. Our XPS Ribs are a little over two years old with about 15-18,000 miles on them; and they look almost new, with very little wear.

We leave large sea-salt and pepper grinders in a wrought iron caddy on the dinette table (on a rubber, non-skid mat) while traveling; and they do not tip over, move around or fall off on the floor. The same with the liquid hand-soap pump, etc., by the bathroom sink.

SteveH · 03-22-2013, 07:03 AM

Like I said, we have the Centramatics with 16" wheels/tires, and stuff flies all over the inside of the trailer, draws keep opening, sliding closet doors keep coming off their tracks, and I have had to reinstall the rear sliding bedroom door twice.

Is this because of, or in spite of the Centramatics?

Hiho Silver · 03-22-2013, 11:38 AM

I've been shopping for tires to go with my new Sendel T03 wheels.
Does anyone know the difference between the 16" Michelin M/S and M/S 2.
The tire salesman says the M/S 2's are replacing the M/S, and have a longer tread warranty. However, it seems most people on the forum are using the Michelin LTX M/S 225/75 R 16 load range E, not the M/S 2. Any advise on my upcoming purchase.

Inland RV Center, In · 03-22-2013, 11:51 AM

Centramatic, within reason, take care of unbalanced running gear.

Centramatics do not compensate for excessive rated tow vehicles or excessive rated hitch bars.

Andy

Gene · 03-22-2013, 01:59 PM

Quote:

Originally Posted by SteveH

Like I said, we have the Centramatics with 16" wheels/tires, and stuff flies all over the inside of the trailer, draws keep opening, sliding closet doors keep coming off their tracks, and I have had to reinstall the rear sliding bedroom door twice.

Is this because of, or in spite of the Centramatics?

Don't forget the driver as one of possibilities Steve. Isn't Texas the state with the 85 speed limit on some highways?

We've had things open and things move, but it must be when Barb is driving. There appears to be less of that with Centramatics.

The M+S 2 wasn't available when we got our Michelins, so that may be why some people use M+S.

Gene

SteveH · 03-22-2013, 02:10 PM

Yes, Gene, Texas has some highways with speed limits up to 85, but I don't tow that fast. Really.

I try not to exceed 65 with the trailer.....try.

**Action** · 03-22-2013, 03:00 PM

Quote:

Originally Posted by Inland RV Center, In

Centramatic, within reason, take care of unbalanced running gear. Centramatics do not compensate for excessive rated tow vehicles or excessive rated hitch bars.
Andy

Or worn out parts.

>>>>>>>>>>>>Action

steverino · 03-22-2013, 03:54 PM

Quote:

Originally Posted by SteveH

Is this because of, or in spite of the Centramatics?

An interesting experiment would be to use an accellerometer app such as https://play.google.com/store/apps/d...erometer&hl=en

Drive the same route, at the same general speed, with and without the centramatics. I agree that driving style, as well as the roads typically driven, will have a lot to do with what moves inside the trailer. A bumpy road or a gas station driveway will likely create enough rocking to move things around, regardless of wheel balance.

nickmeloy · 03-22-2013, 05:36 PM

Quote:

Originally Posted by CapriRacer

...
Third, I'm a fan of going larger when it comes to trailers and tires. I like the idea of going from an ST225/75R15 Load Range D to an LT225/75R16 Load Range D (or E, but at 65 psi.), but the clearance has to be checked.

So without any additional info, I would advise you to go for the 16" option.

Can you be more specific as to why you favor this type of change?

I read about the GYM ( and other brands) complaints from those using the ST225/75R15 Load Range D tires and compare these to our experience with the GYM ST225/75R15 Load Range D tires on our 2006 model year 30' Classic and come away confused. Our trailer is in its eighth year of usage (and second set of tires) with zero tire problems.

Is the reported ST225/75R15 Load Range D tire failure problem a very complex problem, or is it more of a combination of loading, towing speed, tire pressure, etc.?

Please, no rants from those that have experienced tire failures on the ST225/75R15 Load Range D tires.

We tow at 55 mph, monitor tire pressure and temperature, and know that our trailer weight is well below the 10,000 pound GVWR rating for this model.

I really don't want to change to 16" rims if the ST225/75R15 Load Range D tires are satisfactory under the conditions under which we use our trailer.

Are there many other owners out there that have experienced what we have with the ST225/75R15 Load Range D tires?

Steve Bryant · 03-22-2013, 06:32 PM

Quote:

Originally Posted by Hiho Silver

Does anyone know the difference between the 16" Michelin M/S and M/S 2?

I've been planning this change (to 16" wheels & tires) for over a year and during that time Michelin has migrated the new production 225/75R16 LRE tires from the M/S design and rubber compound to the M/S 2. As previously mentioned, the M/S 2 is an evolutionary change of the basic M/S series and is supposed to be an incremental improvement.

Steve