Best tires for a 1974 31' er?

[booman80]

I am going to need to replace the tires on my A/S. Can someone tell me which manufacturer makes good tires for it , and where to get them? Right now it has the Michelin 700x15 radial tires like the ones that were on it when it was brand new. I'm not sure but I don't think they make these any more.
Also size, I see the new ones have 235/75x15 Goodyear Marathons.

Any help would be greatly appreciated.

CB

[dwightdi]

Original tires from factory in 1973 were not radials. The 7.00x15 you have on now are bias ply tires. They are stiffer than the radials of equal rating, so you might get a little better ride out of the 2.35/75x 15 you mention above. if you keep the pressure on the low side you will also end up with more sway. keep the pressure up to give you better side wall stiffness and lateral stability. Make sure you are using the proper load range rated tire with the proper amount of plys in the side wall. You should also make sure they are trailer tires rather than car tires to get better life and tracking out of them.

[booman80]

Thanks dwhitedi-

Any suggestions on makes of tires, load range , and plys?

CB

[Frank S]

Hi booman80--More info than you want is posted on thread "Tires-Tires-Tires".--Frank S

[ticki2]

FWIW , my '76 owners manual listed a 700x15 XC radial tire as an option on all dual axle models , 23' to 31' . The standard tire for the above was 700x15 6 ply , the 700x15 8 ply for single axle models , was NR for dual axle models.

NR -- not recommended by tire manufacturer

This should shed a little more darkness on the topic

[Pick]

I replaced my tires a couple of years ago with 7.00 X 15 bias ply, Load range D. May go with Goodyear Marathons next go round. I have a new set of Marathons on a 10,000 gvw flatbed equipment trailer and they do run cooler than the bias ply, even with 9000 on the tandems.

[overlander63]

Originally Posted by ticki2

FWIW , my '76 owners manual listed a 700x15 XC radial tire as an option on all dual axle models , 23' to 31' . The standard tire for the above was 700x15 6 ply , the 700x15 8 ply for single axle models , was NR for dual axle models.

NR -- not recommended by tire manufacturer

This should shed a little more darkness on the topic

The single axle trailers had two load range D tires, because there were half as many tores to carry the load. A double axle trailer had less weight per tire, so the load range C tires could be used for a softer ride without oevrloading the tires.

[ticki2]

Originally Posted by overlander63

The single axle trailers had two load range D tires, because there were half as many tores to carry the load. A double axle trailer had less weight per tire, so the load range C tires could be used for a softer ride without oevrloading the tires.

I understand the reasoning for this , and agree . What I was trying to point out is that not only can C rated tires be used on dual axle units of this era but it is NOT recommended to use D rated tires. It seems that it may be just as bad to over tire as it is to under tire , and the same for inflation. The systems need to be matched ,( tires , wheels , inflation , and axles ) to the actual weight they will carry. Sometimes more is not better

[overlander63]

Originally Posted by ticki2

The systems need to be matched ,( tires , wheels , inflation , and axles ) to the actual weight they will carry. Sometimes more is not better

I agree. I have seen wheels come apart when they have tires installed that are too much for them. Most automotive wheels are rated for either 35 PSI or 41PSI. If we put on a tire that can have 50 (C range) or 65 (D range) this can cause the rim part of the wheel to fail. There is a thread kicking around here somewhere that addresses that issue at length. The gist of the thread is, if you are going to use load range D tires on load range C wheels, make sure you only inflate to the load range C pressure to avoid this from happening.

[Pick]

I run my D rated bias ply at 50 PSI, and have never had a problem. They are going on 3 years old. My C rated spare has 45 PSI max rating, and I keep that much in it.

4- "C" rated tires at 1720 load rating, is 6880, to close for my comfort level.
4- "D" rated tires at 2080 load rating, is 8320, much better feeling, especially at highway speeds.

[Beginner]

booman80
Be very careful.
The wheel wells in our trailers are quite narrow.
May I suggest that you email Airstream directly and ask them what tire they recommend for your unit. This information is useful in your decision later on what tire to go to.

The Michelin XCA 700:15 was the original tire on my 1984 Excella 31 ft according to the owners manual and the shop manual.

Due to the problems I encountered with Special Trailer tires (Nankang Marathon, ETC.) and the problems encountered by others who frequent this Forum, I decided to go with another size rim. What I ended up with was the BF Goodrich Commercial T/A LT225/75R16 for three reasons.

1. Except for the Cooper Custom Trailer Plus, none of the Special Trailer tires are speedrated for over 65 MPH or 100 Degree F. concrete. So if you ever go over 65 or run on concrete over 100 Degrees F you have over stressed the tire. The Cooper Custom Trailer Plus (ST225/75T15) carries a speedrating (appearntly the overall acid test of tire durability) of 112 MPH, because of Coopers marketing restrictions, I could not purchase their tire in my area.

2. It seems to me to be an industry attitude that all manufacturers are moving away from heavy duty/high load 15 inch tires. Sixteen inch tires are plentiful.

3. Michelin owns B. F. Goodrich. The Goodrich Commercial T/A is the same Outside Diameter (OD) as the original Michelin XCA, and the same width as the Goodyear Marathon ST225/75R15. I have been in email contact with Airstream owners in France and was told that the only tires that they were NOT having trouble with were made by Michelin, Goodrich and Pirelli.

I am not the only one to go to the LT225/75R16 LRD Commercial T/A, Bob Thompson already his milage on his and no problems.

The decision is yours. You can refer to:

http://www.airforums.com/forum...res-16506.html

for a more in depth discussion.
Beginner

[booman80]

Hey Guys, thanks for all the tire info!

I'll probably try the Coopers if I can get them, I really don't want to change the original aluminum wheels that came on it when it was new.

Happy Airstreamin!



Booman