New rims and tires for a light 22' tandem Argosy

[elmer]

I've spent hours reading the threads here and following the links to external documents, and am thoroughly confused.

I recently purchased a 1976 22' Argosy and am having the running gear totally replaced for my peace of mind.

It's currently in a local trailer shop having the 2 new 3500lb axles, 12" drums, shocks and centramatic balancers put on that I bought from Andy at Inland RV (who was extremely helpful and a lot of fun to talk to).

Now it's time to pick the rims and tires.

I was assuming that I'd get 15x6, 6 lug on 5.5 trailer rims, and go for ST225/75/R15 D tires ... but then I came here and started reading

So now I'm confused. I can see that people with the larger or heavier tandem axle trailers, or with the heavy single axle trailers are recommending 16" rims and Michelin LTX tires.

OTOH ... I've got the lightest tandem axle setup with a GVWR of only 5800lbs and GAWR of 2600lbs.

So then there's the camp that recommends 15" rims and the Michelin LTX MS/2 P235/75/R15 XL tires ... which seem to match my original 7.00-15LT tires more closely than the ST-D tires.

But there's the question of sidewall strength ... particularly when turning a tandem axle trailer ... which I definitely have to do when backing it up into the driveway (and hopefully not going up the kerb), or doing a 3-point turn when visiting the kids at the ex's house. Aren't the ST tires the ones designed for this situation?

When it comes to rims, I like the Argosy's painted look (and the idea of having a custom paint job done), so simple white steel rims (that could be painted) might fit more than new aluminum rims (I positively HATE chrome rims). What should I look for in new rims? If I go for the LTX tires, should I get 15x6.5 rims instead of 15x6 rims?

What would you guys recommend for a light old trailer like this?

[elmer]

Well ... since I'm not getting much of a response, I thought that I'd at least report the results of my continued research with the Argosy Owners Manual and Barry's Tire Tech website.

It looks like the old 76 tandem Argosy trailers (all lengths) came with 7.00x15LT 6-ply tires that the Airstream factory gurus recommended be pressurized to 40psi ... for a load rating of 1610lbs per tire.

So I'm figuring that a Michelin LTX MS/2 P235/75/R15XL tire on a 15x6 rim should be a decent replacement for me, and I almost certainly don't need to go the ST225/75/R15D route.

So now it's time to go off and pick some nice looking 15x6 rims.

[idroba]

I think you are on the right track, and could use either 15 or 16 inch wheels. When I changed my single axle 20' Argosy tires I went to the 16 inch wheels and Goodrich LT 225/75 R 16 tires. I have been very happy with the changeover. My load on the single axle is higher than yours on the doubles, of course. But the main point I am making is that Michelin are not the only tires you can get which are good quality. The GMC motorhome community (GMC's made '72 to '78) has found that the Goodrich LT tires in the 16" size have held up very very well and it is the exact tire that will fit the 16" rims we use on the Airstreams and Argosys.

[DKB_SATX]

There are lots of us with lots of miles on tandem-axle trailers with the 15" Michelins without sidewall problems I've ever heard about. I'm very happy with mine so far, they are vastly better than the Carlisles they replaced about running cool and maintaining air pressure over time.

[barts]

The stress on sidewalls is in your mind

Remember, when you go around a corner really fast in your car, you slide the tires. This is the same thing that happens when you make a really tight turn (usually backing) w/ your Airstream. The only thing is, you can set the hand brake and go out and look at those tires, all bent out of line.
When you're doing 35 on a 20 mph turn in a car, the same thing is going on.... so don't worry; the tire will skid (and does) when there's too much side force.

Now, DO make sure your tires are properly inflated. Grossly underinflated tires can cause problems in tight turns - on trailers or on cars.

We have three years and 20k + miles on our 15" Michelins - they look brand new and continue to work very well, both on road and off-road.

- Bart

[overlander63]

Since your axles are more than 25% higher capacity than the person that sold you the axles recommends, I would suggest trying load range C tires to try to compensate for the beating your trailer is going to receive from them. The maximum recommended capacity increase is only 10% over original, and yours are 35% over.
Do a forum search on "overhitched", and "stiff suspension". You can also look up "soft ride".

[AirsDream]

I think you'll be fine. I have a 23' Safari and it came with 14" wheels. After several zillion miles with Goodyear Marathons and no issues, I "upgraded" to 15" wheels and tires and went with Michelin LTXs. I think they are LR D, but can't recall. I run them at 45 psi, and after more tens of thousands of miles, am still a happy camper - no popped rivets, no discernible issues at all. ('course, I was happy with the ST Marathons, which many on the Forms will tell you are the kiss of death!)

Barts overlooks one issue: I think that STs are made with stiffer sidewalls for several reasons - one is that they then are less "compliant" and tend to track straighter, making less work for your sway control system. Another is that they are probably somewhat more resistant to sidewall damage from "curbing" the tires. But if you hit a lot of curbs, you're gonna' tear up whatever tires you have on there, so I don't think it's much of an advantage. And mine tracks just fine, thank you very much.

Keep 'em balanced (Centramatics ought to see to that) and keep the air pressure where it's supposed to be and you should to fine. Just a hint: low air pressure is what kills most tires, because it leads to overheating. So I check air pressure every morning, and then I carry a little infrared thermometer and check tire temps (and also hub temps - as a proxy for bearing temps) at EVERY stop. Some folks think I'm nuts, but a.) I used to be in the tire business, and b.) I've never had a blowout in my life ... and I intend to keep it that way.

[elmer]

Originally Posted by idroba

I think you are on the right track, and could use either 15 or 16 inch wheels. When I changed my single axle 20' Argosy tires I went to the 16 inch wheels and Goodrich LT 225/75 R 16 tires. I have been very happy with the changeover. My load on the single axle is higher than yours on the doubles, of course. But the main point I am making is that Michelin are not the only tires you can get which are good quality.

Thanks. From my limited understanding, the 16" rims/tires would be overkill for my tandem axle trailer ... not bad in any way, but a lot more expensive for no real benefit. OTOH ... with your single axle trailer, it looks like they're the only safe choice for you.

I'm looking at other tire manufacturers ... I've actually been using Hankook tires on my truck for years and see that their Dynapro HT P235/75/R15T is an All-Season Highway tire with almost identical specs to the Michelin.

[elmer]

Originally Posted by overlander63

Since your axles are more than 25% higher capacity than the person that sold you the axles recommends, I would suggest trying load range C tires to try to compensate for the beating your trailer is going to receive from them. The maximum recommended capacity increase is only 10% over original, and yours are 35% over.
Do a forum search on "overhitched", and "stiff suspension". You can also look up "soft ride".

Thanks, but I believe that the axles are correct ... Andy at Inland RV sold them to me knowing exactly what trailer they were going on, and each axle has a 3500lb sticker on it.

With the 20% derating for tandem usage that I found mentioned in another thread here, that puts them at 2800lb each, well within the 10% upgrade range.

[elmer]

Originally Posted by barts

The stress on sidewalls is in your mind

I do tend to be a worrier!

Originally Posted by barts

Now, DO make sure your tires are properly inflated. Grossly underinflated tires can cause problems in tight turns - on trailers or on cars.

Well, I've decided to go with the Michelin P235/75/R15XL tires on 15x6 Sendel T03 rims (if someone still has them in stock).

The best deal that I could find on the Hankook P235/75/R15XL tires was only about $20 each cheaper, and my peace of mind in going for a known-good solution is well worth the $100 difference to me.

The next question is definitely the inflation pressure on the Michelins ... which I'm guessing should either be 40 or 45 psi.

Does anyone have the load/psi data for the P235/75/R15XL tires?