Visit our Popular Forums

Nomad_Tex · 02-23-2013, 09:06 PM

First off, I am new at this. i recently bought a 1967 airstream ambassador and am in the process of ordering new axles from Inland. The current tires likely need to go to but i wanted to get some recommendation for this vintage. They currently have a set of 6 ply 15 X 7LT tires (in really good shape) on what appears to be the original set of rims. What tires would best replace these? Radials/bias ply?

eljay · 02-24-2013, 05:40 AM

Hi! and welcome! There are varying opinions on tires. This is one of my favorite threads:
http://www.airforums.com/forums/f438...res-29435.html

CapriRacer · 02-24-2013, 07:05 AM

Nomad,

Eljay gave you a link to a very long thread - and unfortuantely, it has some bad information in it - and in partcular from Andy at Inland RV Center.

So allow me to start over.

You have a trailer with a 7.00-15LT. I'm going to guess the tire is a 6 Ply Rating - now known as a Load Range C. You need to check that, because the load carrying capacity is extremely important as overloaded tires can fail - and fail catastrophically with little warniing.

7.00-15's are a little hard to find. Your best source is the internet as the local tire store probably doesn't even know what those are.

But there are some alternatives that may be a bit easier to find - so here's the math:

A 7.00-15LT Load Range C is 29.6" in diameter, 8.0" wide on a 5.5" rim, with a load carrying capacity of 1710# at 45 psi (50 for radial tires)

An ST205/75R15 Load Range C is 27.1" in diameter, 8.0" wide on a 5.5" rim, with a load carrying capacity of 1820# at 50 psi. A side note: You can also use a Load Range D - if you decide to go the ST direction I would recommend that you do.

Now some folks are not fans of ST type tires and may recommend an LT235/75R15 Load Range - which is 28.9" in diameter, 9.3" wide on a 6.5" rim (it doesn't fit on a 5.5" rim) and has a load carrying capacity of 1985# at 50 psi. Please note the width and the rim width issue.

And here is where Andy was wrong: Youy CAN use a higher Load Range IF the load doesn't change. It isn't the tire that causes wheels to fail - it's the load. And so long as you are using the same load on the wheel, it doesn't matter how high in Load Range you go.

Lance M · 02-24-2013, 08:29 AM

Quote:

Originally Posted by Nomad_Tex

First off, I am new at this. i recently bought a 1967 airstream ambassador and am in the process of ordering new axles from Inland. The current tires likely need to go to but i wanted to get some recommendation for this vintage. They currently have a set of 6 ply 15 X 7LT tires (in really good shape) on what appears to be the original set of rims. What tires would best replace these? Radials/bias ply?

Hi Nomad,
Capri Racer knows what he is talking about.

I use, and highly recommend, the Michelin LTX M/S2 P 235/75/15 XL tires. If you are looking for something more original looking, then I recommend the Yokohama RY 215 7r15LT

Have fun!

Nomad_Tex · 02-25-2013, 05:47 AM

Thanks everybody.

Sounds like the big winner is the Michelin LTX M/S2P 235/75/15XL, but i will be needing new rims to boot..? The original rims are 15X5.5 and these tires require 15X6.5 ? Guessing my local tire shop could confirm but you guys are more credible.

Presumably there are no clearance issues....the current tires seem like a pretty tight fit....

CapriRacer · 02-25-2013, 07:05 AM

Quote:

Originally Posted by Nomad_Tex

Thanks everybody.

Sounds like the big winner is the Michelin LTX M/S2P 235/75/15XL, but i will be needing new rims to boot..? The original rims are 15X5.5 and these tires require 15X6.5 ? Guessing my local tire shop could confirm but you guys are more credible.

Presumably there are no clearance issues....the current tires seem like a pretty tight fit....

I would check the clearance very carefully BEFORE pulling the trigger.

BlackAces · 02-25-2013, 07:44 AM

Quote:

Originally Posted by Nomad_Tex

First off, I am new at this. i recently bought a 1967 airstream ambassador and am in the process of ordering new axles from Inland. The current tires likely need to go to but i wanted to get some recommendation for this vintage. They currently have a set of 6 ply 15 X 7LT tires (in really good shape) on what appears to be the original set of rims. What tires would best replace these? Radials/bias ply?

Here is a reference to a nice looking tire that is in your fitment “Ball Park”

http://www.tirerack.com/tires/tires.jsp?tireMake=Goodyear&tireModel=Cargo+G26&si dewall=Blackwall&partnum=97R5G26&tab=Specs

BA

Nomad_Tex · 02-26-2013, 05:21 PM

Not to belabor the point but it looks like I found a tire that is the exact same dimension as my current 15 x 7....the Carlisle Sport Trail ST205/90 R 15. Anybody have any experience with these? Apparently Carlisle is owned by Goodyear.

Nomad_Tex · 02-26-2013, 05:22 PM

Load range D.

CapriRacer · 02-27-2013, 05:59 AM

Quote:

Originally Posted by Nomad_Tex

Not to belabor the point but it looks like I found a tire that is the exact same dimension as my current 15 x 7....the Carlisle Sport Trail ST205/90 R 15. Anybody have any experience with these? Apparently Carlisle is owned by Goodyear.

Good find, but I think you'll find that Carlisle is its own company. They may farm out the making of tires to Goodyear (I doubt it!), but would be the exyent of their relationship.

Lance M · 02-27-2013, 06:13 AM

Quote:

Originally Posted by Nomad_Tex

Not to belabor the point but it looks like I found a tire that is the exact same dimension as my current 15 x 7....the Carlisle Sport Trail ST205/90 R 15. Anybody have any experience with these? Apparently Carlisle is owned by Goodyear.

I bought a set of these (LR-C) at Discount Tire before I towed my '51 Flying cloud home from the Florida panhandle. It was the least expensive "get home" option that would fit. It was just a few weeks ago. The tires felt unusually warm after a long stretch of road. I was towing at 55MPH and the ambient temps were in the mid 50s to 60s. After I got back and weighed the trailer I had 2,680 pounds on the axle. I know some people that love bias ply tires. The Carlisle Sport trail in particular. I will be replacing them with a set of Continental Vanco 2 215/70/15 LR-D before any extended towing in high temps.

Good luck!

Not Done · 02-27-2013, 08:21 AM

Ummm, I wouldn't make a habit of ignoring what Andy says. Imagine being on trial for involuntary manslaughter for a highway accident that you caused and your defense is "I did the opposite of what one of the nations top experts on Airstreams said to do. I don't understand what went wrong."

**Action** · 02-27-2013, 06:16 PM

Quote:

Originally Posted by Not Done

Ummm, I wouldn't make a habit of ignoring what Andy says. Imagine being on trial for involuntary manslaughter for a highway accident that you caused and your defense is "I did the opposite of what one of the nations top experts on Airstreams said to do. I don't understand what went wrong."

If there was an accident with the person being at fault it would be a rare to have a civil trial. Most insurance companies just write a check. A criminal trail is unheard of. And bad attorney's advise be to put the person cited for at fault on the stand. That almost never happens.

With that said, Nations top expert rating is one I have not seen.

>>>>>Action

n2916s · 02-27-2013, 06:24 PM

I had Carlisles. Mine failed randomly in rather catastrophic fashion even though I am downright anal about tire maintenance. Never again.

Mike

Nomad_Tex · 02-27-2013, 07:07 PM

Point taken on the Carlisles....stay far away....

New axles are on the way...so once in place clearance will undoubtedly change, but given today's measurements, the MichelinLT235/75R15 will be too close to the skin apron particularly on the front tires. So I am left with the following near 15x7 sizing:
1) Continental Vanco 2 215/70/15 LR-D
2) Maxxis M8008 ST Radial
3) Yokohama RY 215 7r15LT

Tomorrow is the last day of the discount tire sale and they are seeing what of these three are available. If anybody has a strong visceral view feel free to spew it out....

Not Done · 02-27-2013, 07:42 PM

@ Action: I'll state it a different way then.

Imagine how a normal person would feel if they caused a death due to ignoring the advice of someone with decades of experience on the topic.

**DKB_SATX** · 02-27-2013, 08:51 PM

Quote:

Originally Posted by Not Done

@ Action: I'll state it a different way then.

Imagine how a normal person would feel if they caused a death due to ignoring the advice of someone with decades of experience on the topic.

I'll point out here that CapriRacer is a tire engineer. If I'm going to choose between them on tire advice, I think I'd go with the tire engineer.

Not Done · 02-27-2013, 10:40 PM

Thanks DKB, that sounds reasonable in the context of that application outlined by CapriRacer.

I have question/concerns (not being sarcastic).
So IF there is risk of wheel damage by using that wheel/tire assembly in a higher rated application, I would still have reservations. Reason is the wheel/tire assembly has a lower rating than is indicated on the tire. That assembly might be on a flatbed trailer next year (with a new owner) and used according to the tire's rating resulting in wheel damage.

Second one, doesn't the higher rated tire have a stiffer sidewall? One concern regarding stiffer rides is possible AS damage, ie missing rivits.

I have some other tire questions but I'll start a new thread for those

CapriRacer; I hope that you'll chime in because I'd like to get your thoughts.

CapriRacer · 02-28-2013, 06:53 AM

First, I want to thank folks for the vote of confidence. I'm not an RV'er. My intent is to help folks with tire questions - and as you all know, there's a lot of strongly held opinions with very little evidence. I want to cut through that to get at the "truth" - as best I can.

So onto the questions:

Quote:

Originally Posted by Not Done

Thanks DKB, that sounds reasonable in the context of that application outlined by CapriRacer.

I have question/concerns (not being sarcastic).
So IF there is risk of wheel damage by using that wheel/tire assembly in a higher rated application, I would still have reservations. Reason is the wheel/tire assembly has a lower rating than is indicated on the tire. That assembly might be on a flatbed trailer next year (with a new owner) and used according to the tire's rating resulting in wheel damage......

I can appreciate the thought, but I think we're talking about a situation where the trailer is an RV and there's a problem to be solved. The load on the tire isn't changing, it's a question of using a tire with a higher POTENTIAL load carrying capacity - and that's going in the right direction. What happens later - when things are not in the hands of the guy who makes such a change - is an unlikely situation.

Quote:

Originally Posted by Not Done

.......

Second one, doesn't the higher rated tire have a stiffer sidewall? One concern regarding stiffer rides is possible AS damage, ie missing rivits........

Yes, they have a stiffer sidewall, but it isn't like the tire is TWICE as stiff. If a trailer can't withstand that small difference, then it was only a matter of time before the problems would have surfaced anyway.

Quote:

Originally Posted by Not Done

......
I have some other tire questions but I'll start a new thread for those

CapriRacer; I hope that you'll chime in because I'd like to get your thoughts.

My pleasure. Always available to questions.

Inland RV Center, In · 02-28-2013, 07:17 AM

Quote:

Originally Posted by CapriRacer

First, I want to thank folks for the vote of confidence. I'm not an RV'er. My intent is to help folks with tire questions - and as you all know, there's a lot of strongly held opinions with very little evidence. I want to cut through that to get at the "truth" - as best I can.

So onto the questions:

I can appreciate the thought, but I think we're talking about a situation where the trailer is an RV and there's a problem to be solved. The load on the tire isn't changing, it's a question of using a tire with a higher POTENTIAL load carrying capacity - and that's going in the right direction. What happens later - when things are not in the hands of the guy who makes such a change - is an unlikely situation.

Yes, they have a stiffer sidewall, but it isn't like the tire is TWICE as stiff. If a trailer can't withstand that small difference, then it was only a matter of time before the problems would have surfaced anyway.

My pleasure. Always available to questions.

Your thought's on updating old wheels from "C" that was used for many years, to "D" rating tires, or "E" ratings.

I was told many times that the wheel will split.

Dozens of times, that has been reported to me over the years.

Some say impossible.

Andy