Michelin 16" LT Tire Upgrade

[switz]

The Carlisle ST225/75R15 E tire rated 2830 pounds @ 80psi may be too stiff for a 23D.

Camping Ready 2015 23D on my scales 9 May with extensive modifications - solar &b lithium battery etc.

Tongue………928
Front….1,280……1,246 - total front axle 2,526
Rear…..1,376……1,233 - total rear axle 2,609
Total Axles………………………………….5,135
Total Trailer….6,063

By the time the tire pressure would be reduced by experimentation watching a TPMS for pressure rise and temperature rise, you may have lots of rivets on the floor. That tire might be be okay on a 31' Airstream trailer and even then might have to be be run at reduced pressure.

We run the 16" Michelin LT225/75R16/E LTX M/S2 tire rated 2,680 pounds at 80 psi at 75 psi on our 31' 2014 Classic.

[DoublTrouble]

Switz, thank you for the shopping list. I am in the process of putting it all together for our 2015 27fb International.
Since we are about 7000lbs with approximately 1000 of it on the tongue, where might I set tire inflation on the 16s?

[ratchet]

I just complete an upgrade to the 16 inch Michelin's with new wheels. I also included centramatics all around and TST's internal tire pressure monitoring system. I will be doing a post including pictures of the upgrade soon.

[Tn Traveler]

The upgrade to 16" Michelins and Sendel Wheels was just made to our 'L'l Darlin'. She was towed about 50 miles today just to the shop and back to inside storage. Next upgrade is an outdoor shower. It will take pressure off the grey tank while boondocking.

[pkm123]

I just upgraded my 15" OEM wheels and GYM tires to 16" Sendel T03 wheels with black accents and the tires to Michelin LTX 225/75 16 MS2's on my 2007 19' Bambi. Purchased at our local Discount Tire. They would not install my Centramatic 221 balancers because they were not hub centric, in other words the hub opening in the balancer was bigger than the hub and they claim that it could lead to loosening of the wheel from hub. Has anyone else had a similar experience and how important is it for the Centramatics to fit the hub exactly? i will now have to have someone else install the Centramatics. Upgrades seem to always be a challenge. Also, Switz if you are following this thread, I spoke with Jerry at Centramatics and he assured me that there was no difference in performance between the 221's and 356 balancers on 16" wheels so I decided to keep the 221's and give them a try. He also said the hub centric issue was a non issue. Another question for someone with experience is what pressure should I run in the tires to avoid rivets popping?
Thanks,
Ken

[waldosgone]

Originally Posted by pkm123

I just upgraded my 15" OEM wheels and GYM tires to 16" Sendel T03 wheels with black accents and the tires to Michelin LTX 225/75 16 MS2's on my 2007 19' Bambi. Purchased at our local Discount Tire. They would not install my Centramatic 221 balancers because they were not hub centric, in other words the hub opening in the balancer was bigger than the hub and they claim that it could lead to loosening of the wheel from hub. Has anyone else had a similar experience and how important is it for the Centramatics to fit the hub exactly? i will now have to have someone else install the Centramatics. Upgrades seem to always be a challenge. Also, Switz if you are following this thread, I spoke with Jerry at Centramatics and he assured me that there was no difference in performance between the 221's and 356 balancers on 16" wheels so I decided to keep the 221's and give them a try. He also said the hub centric issue was a non issue. Another question for someone with experience is what pressure should I run in the tires to avoid rivets popping?
Thanks,
Ken

Ken,

You wouldn't happen to have a picture with your new 16'' installed that you would mind posting? I'm going with the black accents because the silver wheels are backordered and I'd like to get them installed before we had back to Alaska. It's not a showstopper I'd just like see what they look like as we have similar trailers (mine is a 20FC).

Thanks,

James

[switz]

Michelin LT225/75R16/E LTX M/S2 tires are rated 2,680 pounds @ 80 psi and are 29.2" in diameter. Michelin P/N 05681

4 x 2,680 = 10,720 pounds $1,187.69 at CostCo when I bought five and had them mounted on the provided SenDel wheels. Tire load versus air pressure table is below for this particular size tire. The letters C, D, and E are the load range letters usually associated with that load capacity tire.

80psi 2,680 (E)
75psi 2,560
70psi 2,440
65psi 2,335 (D)
60psi 2,190
55psi 2,060
50psi 1,940 (C)
45psi 1,790

With a 4,500 GVW on a 19' Airstream, perhaps 72/73 psi where the load capacity is about 2,500 pounds would work with a 20% safety margin. Use the private message system to contact "Phoenix" who has a 19" and was early adopter of this tire and has kept a tire failure questionnaire up for many years.

[Ag&Au]

I am not going to search for them, but there are threads on this subject where members (or a member) who appear to be knowledgeable about tires have stated that when light truck or passenger tires are used on a trailer, the max load must be derated by a certain percentage. I don't remember the exact number, but it is less than the 20% Switz uses in the above post. So his figures should work fine.

Ken

[Steamy1]

I have run 16"s LRE at 80PSI on the Bambi for eight years and have never had a problem. I am much more concerned about under inflation than over inflation, especially on a single axle trailer.

[pkm123]

James,
Here are the pictures you requested. I think the black accents look great. I think they use or used them on Eddie Baur editions. I also added centramatic balancers at the same time. Lots of different opinions on there effectiveness but was able to buy a 2 221's from Centramatic for $100.00 plus $14.00 shipping so what the heck.

Ken

[pkm123]

Let me try uploading the pictures again. Sorry, I am new to this.
Ken

[switz]

Here is the regulation on derating passenger tires load capacity 10% for trailer use:

49 CFR 571.110
Tire selection and rims and motor home/recreation vehicle trailer load carrying capacity information for motor vehicles with a GVWR of 4,536 kilograms (10,000 pounds) or less.

S4.2.2.1
Except as provided in S4.2.2.2, the sum of the maximum load ratings of the tires fitted to an axle shall not be less than the GAWR of the axle system as specified on the vehicle's certification label required by 49 CFR part 567. If the certification label shows more than one GAWR for the axle system, the sum shall be not less than the GAWR corresponding to the size designation of the tires fitted to the axle.

Thus the use of the

S4.2.2.2
When passenger car tires are installed on an MPV, truck, bus, or trailer, each tire's load rating is reduced by dividing it by 1.10 before determining, under S4.2.2.1, the sum of the maximum load ratings of the tires fitted to an axle.

S4.2.2.3
(a) For vehicles, except trailers with no designated seating positions, equipped with passenger car tires, the vehicle normal load on the tire shall be no greater than 94 percent of the derated load rating at the vehicle manufacturer's recommended cold inflation pressure for that tire.
(b) For vehicles, except trailers with no designated seating positions, equipped with LT tires, the vehicle normal load on the tire shall be no greater than 94 percent of the load rating at the vehicle manufacturer's recommended cold inflation pressure for that tire.

Thus the use of the 15" Michelin LTX (P) 235/75R15 XL tires sidewall rated 2,183 pounds @ 50 psi is derated to 1,985 pounds for trailer use. The 28.9" diameter is 0.6" larger than the stock GYM ST225/75R15D with a 28.3" diameter. The Michelins have a larger tire contact patch, are not speed limited to 65mph and can be safely run at 44 psi as their maximum load capacity is attained at 41 psi.

The simple math shows 4 x 1985 = 7,940 pounds load capacity. Remember the tires are not carrying the GVW but just the trailer axle load. So our 25FB axle load fully filled and ready for camping was 5,800 pounds. with the total weight of just under 6,800 pounds. A 27 FB being only 300 pounds higher in GVW than a 25FB could also safely use these 15" tires since not all 300 pounds would be on the axles.

YMMV

[OTRA15]

Thanks for the photos Ken. The new Sendel wheels look great IMO.

Peter

Originally Posted by waldosgone

Ken,

You wouldn't happen to have a picture with your new 16'' installed that you would mind posting? I'm going with the black accents because the silver wheels are backordered and I'd like to get them installed before we had back to Alaska. It's not a showstopper I'd just like see what they look like as we have similar trailers (mine is a 20FC).

Thanks,

James

Originally Posted by pkm123

Let me try uploading the pictures again. Sorry, I am new to this.
Ken

[pkm123]

Thanks Peter,
I have done a lot of upgrades since we purchased in Oct. $KaChing$KaChing$.
Ken

[waldosgone]

Originally Posted by pkm123

Thanks Peter,
I have done a lot of upgrades since we purchased in Oct. $KaChing$KaChing$.
Ken

Thanks for the pictures Ken, they look sharp! Excited to get them put on in a week or so; I know what you mean about $KaChing$... no one tells you about all the little bits and pieces. Of course we're doing this so we don't have to transfer between the house and FC20.

Thanks again!

James

[switz]

An Airstream and the associated expenses is a lot like giving blood. They don't take it all at once, but gradually over the years they can get a lot....

[DoublTrouble]

Yes Switz, I figure 15% more $ in the first year alone.

[subfan1]

I think the dark accents in the wheels complement the dark windows in the trailer, looks great.

[Steamy1]

As mentioned before, I upgraded the tires and wheels on the Bambi to 16" about eight years ago. I went with LT215/85R16E. The Bambi just rolls so much better.

When we took delivery of the 23FB, I replaced the 14" GYM with the 15" Sendels and LTX(P) 235/75R15 XL, but have always had it in the back of my mind if there was a way to go to 16" I even (briefly) considered changing out the axles.

The advice was that it is not a good idea to upsize more than 1".

However, the diameter of the LTX(P) 235/75R15 XL is 28.9" and the LT 225/75R16E is 29.2", a difference of 0.03. This seems negligible.

It seems like the 16" tires would fit, but as there is the concern commented on by switz that LRE may be too stiff. Couldn't this be mitigated lowering the PSI?

I am planning on installing the Dexter lift kit, which should add even more clearance.

I think the challenge will be finding a 16" 5-lug wheel, ideally with a 6" or 7" width. American Racing has one but it is 8" width. This may work but not sure.

I think I am slightly obsessed with trying to fit 16" tires and wheels on the 23", and continue to look for a way to do it. After my experience with the Michelin LT M/S 16" LRE tire on the Bambi, I think it is a significant upgrade.

[xrvr]

Try etrailer, they have a huge selection if wheels. Might have one the size you need.