Going from 15" to 16" wheels with G.V.W.R = 10,000 lbs

[Sky]

Yeah, I know. Just what we need is another 15 - 16 thread.

Hello, I have a 30' 2007 Classic with corroded 15" wheels and worn Marathons. I have been reading the threads on upgrading to 16" wheels and I still have a couple questions.

My trailer's G.V.W.R. is 10,000 lbs, so with a 15% buffer, I think I need wheels and tires that can bear 1.15 x 10,000 / 4 = 2875 lbs per wheel.

When I look up tire inflation info I see the following:
Michelin RIB LT225/75R16 115/112Q = 2680/80 lbs/psi….2335/65 lbs/psi
Michelin Agilis CrossClimate LT225/75R16 115/112R = 2680/90 lbs/psi….2150/65 lbs/psi
Yokohama Geolandar G056 LT225/75R16 115/112S E = 2680/80 lbs/psi
GoodYear Endurance ST225/75R15 117N = 2833/80 lbs/psi….2540/65 lbs/psi

Not one of these provides the load capacity I think I need. Even the GoodYear Endurance is below what I think I need but not as much as the Michelins.

So I have questions:
1. Am I reading these inflation charts wrong?
2. Do I not need a 15% buffer?
3. You guys with 30’ Classics 10,000 GVWR, why do you think you are better off with the 16” stuff? The numbers I am seeing say you are not.
4. The Airstream Manual / Plaque says 65 psi cold. This is confusing as hell. Is this assuming you are still running GY Marathons, or is this what they recommend for any tire to maintain ride quality? Inflating the 16” tires listed above to 65 lbs lowers their load capacity even more.

Will someone that knows what they are talking about, please make me understand. If I go to 16”, now is the time, but until I understand this crap, I am stuck.

Thanks
Dale

[smithcreek]

The Marathons (that came with the trailer?) are rated at 2535 lbs. at 65 psi, so the Endurance are higher to start. Are you at or near your GVWR when loaded? I've been advised a 10% safety margin is adequate, so the Endurance should have you covered.

[jcanavera]

Dale while my Classic slide out has a GVWR of 9,100 lbs., I've carried that weight with a full freshwater tank, and even without that tank full, I regularly carrying about 8,600 lbs. I switched to the 16" Michelin LTX2, and now the Defender series tires after subsequent failures of belts on my D rated Marathon St tires and E rated Maxis St tires. The Marathon's started failing on the last trip of season 3 of use, and the Maxis tires started failing at the first trip of year 4. I kept the Marathon's at 65 psi, and ran the Maxis tires at 80 psi. My conclusion was that the ST rated tires lost reliability due to the high amounts of weight my Classic Slideout carried on a consistent basis.

I decided to go with the Michelin 16" LT LTX2 tires and ran those at 80 psi. The Michelin tires were the first tires I didn't have to be replaced due to failure. I used those for 6 full seasons and decided to replace them this spring with the LT Defender tires from Michelin. I also run 80 psi on them. While Defenders are not being made in the 225 75R 16" size anymore, there are plenty still in stock.

AT this time the Endurance line is a new tire from Goodyear and has yet to be proven on the long run. I carry 80 psi for 2 reasons, first the tires I am using were rated at 80 psi for their maximum load capacity. The second reason is with the weight of my trailer, I want the maximum % of reserve capacity as possible. I've suffered no physical signs for stress structurally on my Classic running at max inflation both with ST and LT tires over the course of 15 years. Even though you have a GVWR of 10,000 lbs, you probably won't get there unless you are carrying full water and waste tanks. Quite honestly it's all a guess without you getting that trailer weighed.

Most of us who moved to 16" wheels and tires did because of the well documented failures of the OEM Goodyear Marathon ST tires. The track record of over 8 years of use of the LT tires has been very good here on the forums. The failure of the Marathon product was not just an Airstream issue but was noted on many other RV forums where Goodyear was the OEM brand.

There are those who have had excellent performance from ST's but as one who is very careful with my tires, and with the ability to keep my trailer inside out of the elements when not in use, the failures I found in my opinion was based on the weight of my trailer and quite honestly going with the LT Michelin was cheaper in the long run than replacing my ST tires every 2 1/2 year to avoid failures.

Jack

[GCinSC2]

Dale,

Care to take a look at your numbers on trailer weight, did you subtract the tongue weight that is carried by the TV? That should knock your number down by what 900-1000 lbs .

And I also chose the 16" Michelins like Jack posted these 30' Slide Outs are some of the heaviest tandem axle rigs not sure where the new 33's are in weight.

Gary

[Sky]

Thanks Jack and Gary and smithcreek. Jack, your Classic must be heavier than mine unloaded, so I really value your thoughts. I require new Marathons every 3 or 4 years, and I have had a couple issues. If I can get 6 or 7 years from Michelins, the extra cost may be worth it.

Gary, you are correct. I need to subtract the tongue weight which I did not. While looking at my trailer’s specs I decided to change the total weight from 10,000 lbs GVWR to something more realistic. Based on Airstream’s specs for a 2007 30’ Classic:
7095 UVW + 1140 (all tanks full) + 700 cargo - 670 Tongue Wt = 8265 lbs
1.15 x 8265 / 4 = 2375 lbs/tire

I found a couple posts from people that actually weighed their 2007 Classic, and my estimate compares well.

This makes more sense I think

This tells me I could run any of those tires around 65-70 psi and be fine.

I am thinking about going with Sendel T03 wheels and Michelin RIBs

Thoughts?

[jimfa440]

I have a 30' Excella. I bought the Sendel 16" wheels and Michelin LT load range E tires. No problem handling/loading. I air to 65# cold. Never have to worry.
Happy Camping

[Rgentum]

"I am thinking about going with Sendel T03 wheels and Michelin RIBs."

I did that two years ago --- so far, a bullet-proof result.

Both the wheels and the tires were EXPENSIVE!!! The Sendels retailed for $95 and the RIBs for $235.

BUT, I got them during a sale at Discount Tire, which reduced the total price to slightly over $1,000 (for four RIBs on new Sendels). In my experience, Discount Tires has significant sales and discounts over major holidays. As I recall, I got mine around a July 4th holiday, and one of those is now approaching in just a week or so.

[pappy19]

Originally Posted by Rgentum

"I am thinking about going with Sendel T03 wheels and Michelin RIBs."

I did that two years ago --- so far, a bullet-proof result.

Both the wheels and the tires were EXPENSIVE!!! The Sendels retailed for $95 and the RIBs for $235.

BUT, I got them during a sale at Discount Tire, which reduced the total price to slightly over $1,000 (for four RIBs on new Sendels). In my experience, Discount Tires has significant sales and discounts over major holidays. As I recall, I got mine around a July 4th holiday, and one of those is now approaching in just a week or so.

After 3 blowouts on GYM's, I made the switch to 16" Sendels and Michelin Defender E rated on my 2002 30' Classic Slider. I run mine at 70 lbs. After close to 50,000 miles on them, they still look brand new. I also installed Centramatics on all 4 wheels made specifically for Airstreams. They also have them for 3/4-1 ton pickups and I added them too.

[franklyfrank]

Originally Posted by Sky

Yeah, I know. Just what we need is another 15 - 16 thread.

Hello, I have a 30' 2007 Classic with corroded 15" wheels and worn Marathons. I have been reading the threads on upgrading to 16" wheels and I still have a couple questions.

My trailer's G.V.W.R. is 10,000 lbs, so with a 15% buffer, I think I need wheels and tires that can bear 1.15 x 10,000 / 4 = 2875 lbs per wheel.

When I look up tire inflation info I see the following:
Michelin RIB LT225/75R16 115/112Q = 2680/80 lbs/psi….2335/65 lbs/psi
Michelin Agilis CrossClimate LT225/75R16 115/112R = 2680/90 lbs/psi….2150/65 lbs/psi
Yokohama Geolandar G056 LT225/75R16 115/112S E = 2680/80 lbs/psi
GoodYear Endurance ST225/75R15 117N = 2833/80 lbs/psi….2540/65 lbs/psi

Not one of these provides the load capacity I think I need. Even the GoodYear Endurance is below what I think I need but not as much as the Michelins.

So I have questions:
1. Am I reading these inflation charts wrong?
2. Do I not need a 15% buffer?
3. You guys with 30’ Classics 10,000 GVWR, why do you think you are better off with the 16” stuff? The numbers I am seeing say you are not.
4. The Airstream Manual / Plaque says 65 psi cold. This is confusing as hell. Is this assuming you are still running GY Marathons, or is this what they recommend for any tire to maintain ride quality? Inflating the 16” tires listed above to 65 lbs lowers their load capacity even more.

Will someone that knows what they are talking about, please make me understand. If I go to 16”, now is the time, but until I understand this crap, I am stuck.

Thanks
Dale

Our 30' Classic came with 16" Michelins E rated tires. Even with full water, road ready I am under 8,000 Lbs road ready. I run them at 72 psi for a great ride.

[hhendrix]

Well stated Jack and my experiences are identical to yours. GYM failures, Tow Max blow out, and Comodore (replacing the Tow Master blow out) tread separation. 16" Sendels and Michelins LT's and no more worries.

[PKI]

One other consideration is cross load differences. Forum tire experts post that tires can be ~20% different in weight from one to another. They also state RVs are often found overloaded when weight is checked.

The good news is that you are researching and learning. Now, validate that info with your own measurements. Load out the trailer and head to a CAT scale. Note, they don't allow off center transit that would allow side to side weights to be determined, but the axle weights are a good start toward your objective. Understand that there are RV groups who have scales that will provide the individual tire measurement. Maybe someone can provide a contact.

Good luck with your investigation. Pat

[GammaDog]

The Escapees RV club SmartWeigh program is a good place to start digging in to more precise weight measurements than a CAT scale would give you.

I upgraded from the original Michelin LTX that came on my trailer to Michelin RIBs a year ago. Michelin tech support said the RIBs are their recommended tire for this application. I've been very happy so far. Most noticeably, I get better overall fuel economy with the RIBs than the LTX.

[Sky]

Thanks Jim, Rgentum, Pappy, Frank, hhendrix, Pat, and GammaDog!

Thanks Rgentum for the tip about the Discount Tire 4th July sale, it starts tomorrow

GammaDog, that is great news about the mileage, hope it holds true for me. BTW how many miles did you have on the LTXs you replaced?

[switz]

Our 2014 31' Classic numbers on my individual wheel scales after all the modifications and full propane and water tanks. SenDel T03-66655T wheels

Classic Scale numbers May 2014

……1200……——1200

2034……2042—4076

1921…….2062—3983

Total weight——9259

Michelin LT225/75R16/E LTX M/S2 tire run at 75 psi

[Bill M.]

I personally think they test the "load capacity" differently for ST tires and for real tires. So I would rather have the 16" Michelins at capacity than a ST tire that shows some "reserve".

[james.mileur]

RIBs are a "Summer Tire". Might not be great as LTX for year round.

[suncoasteng]

We run Michelin LT 16-inch E load tyres on our small dually dump trucks carrying up to 16,000 lb loads with no problems, so we also use them on our heavy equipment trailers.

[Sky]

Originally Posted by james.mileur

RIBs are a "Summer Tire". Might not be great as LTX for year round.

Thanks James, definitely something to take into consideration if buying the RIBs

[james.mileur]

Search for posts from Tireman if you want way more insider trading info for tires.

[Rgentum]

"RIBs are a "Summer Tire". Might not be great as LTX for year round."

__________________________

Michelin RIBs are a "hard rubber" tire:
Advantage = Great mileage. (I've heard of some truckers getting 100K miles on them.)
Disadvantage = Lousy in cold, snow, or ice. There, "stickier" tires would be better.

I haven't had any problem using them in the Northwest (WA, OR, etc.), but then, I don't go camping in the snow or ice.