Tires for my 1967 airstream Cavarel

[ngkellyk]

Hi, anybody heard of Power King tires for trailers? Are they good tires? If not, any recommemdations?
thank you very much

[perryg114]

The trend on tires is to go with 225/75-R15 XL truck tires. Trailer specific tires are leading to failures because they are designed for occasional use. They are a little bigger than the 15 inch trailer tires so if you don't have much clearance they may not fit. Power King sounds like one of the many Chinese brand trailer tires.

Perry

[AWCHIEF]

From the Power King site: Power King Tire

Interesting information from Trailer Tire Facts - Discount Tire




Trailer Tire Applications

• Trailer tires are designed for use on trailer axle positions only. They are not built to handle the loads applied to, or the traction required by, drive or steering axles.
• An "LT" designation on a trailer tire size specifies load range only. It is not designed for use on light trucks.
• Do not mount "ST" or "LT" trailer tires on passenger cars or light trucks.

Inflation

• Always inflate trailer tires to the maximum inflation indicated on the sidewall.
• Check inflation when the tires are cool and have not been exposed to the sun.
• If the tires are hot to the touch from operation, add three psi to the max inflation.
• Underinflation is the number one cause of trailer tire failure.

Load Carrying Capacity

• All tires must be identical in size for the tires to properly manage the weight of the trailer.
• The combined capacity of the tires must equal or exceed the Gross Vehicle Weight (GVW) of the axle.
• The combined capacity of all of the tires should exceed the loaded trailer weight by 20 percent.
• If the actual weight is not available, use the trailer GVW. If a tire fails on a tandem axle trailer, you should replace both tires on that side. The remaining tire is likely to have been subjected to excessive loading.
• If the tires are replaced with tires of larger diameter, the tongue height may need to be adjusted to maintain proper weight distribution.

Speed

• All "ST" tires have a maximum speed rating of 65 mph.
• As heat builds up, the tire's structure starts to disintegrate and weaken.
• The load carrying capacity gradually decreases as the heat and stresses generated by higher speed increases.

Time

• Time and the elements weaken a trailer tire.
• In approximately three years, roughly one-third of the tire's strength is gone.
• Three to five years is the projected life of a normal trailer tire.
• It is suggested that trailer tires be replaced after three to four years of service regardless of tread depth or tire appearance.

Mileage

• Trailer tires are not designed to wear out.
• The life of a trailer tire is limited by time and duty cycles.
• The mileage expectation of a trailer tire is 5,000 to 12,000 miles.

Why Use An "ST" Tire

• "ST" tires feature materials and construction to meet the higher load requirements and demands of trailering.
• The polyester cords are bigger than they would be for a comparable "P" or "LT" tire.
• The steel cords have a larger diameter and greater tensile strength to meet the additional load requirements.
• "ST" tire rubber compounds contain more chemicals to resist weather and ozone cracking.

Storage

• The ideal storage for trailer tires is in a cool, dark garage at maximum inflation.
• Use tire covers to protect the tires from direct sunlight.
• Use thin plywood sections between the tire and the pavement.
• For long term storage, put the trailer on blocks to take the weight off the tires. Then lower the air pressure and cover the tires to protect them from direct sunlight.

Maintenance

• Clean the tires using mild soap and water.
• Do not use tire-care products containing alcohol or petroleum distillates.
• Inspect the tires for any cuts, snags, bulges or punctures.
• Check the inflation before towing and again before the return trip.

Keys to Avoiding Trouble

• Make sure your rig is equipped with the proper tires.
• Maintain the tires meticulously.
• Replace trailer tires every three to five years, whether they look like they're worn out or not.

*#*#*#*#
PS: Extensive damage was done to the bottom of my Bambi II when a truck tire that was mounted by the previous owner exploded. His recommendation was do not under any circumstances put truck tires on a travel trailer.

[Tom Nugler]

I replaced the truck tires on my '67 Globetrotter with load range C Goodyear Marathons. Ran them for 5-6 years without any problems.
Goodyear currently doesn't produce C's so I went with D's on the Tradewind.
The new tires are made in the USA. The reported problems with Marathons in the past overwhelmingly appear to be confined to Chinese built tires on larger rigs.
You can put the Marathon D's on the Caravel but you will have to get the rig weighed in order to get the tire pressures correct. There is an inflation/load table on the Goodyear website.

Just my 2 cents,
Tom

[rideair]

If you are talking about the 7.00x15 Power Kings bias-ply tires. I have two words:

LOVE THEM!!!

I have them on a couple of trailers (1966 Overlander, 1966 Safari and a 1956 Safari FK that is being restored) and they have done very well.

The thing about a Marathon radial, ask anyone that's had a blowout what the side of their trailer looks like afterwards compared to a bias-ply blowout.

Like them and will buy again!

Enjoy,

[idroba]

I don't understand these statements:


"ST" tires feature materials and construction to meet the higher load requirements and demands of trailering.
The polyester cords are bigger than they would be for a comparable "P" or "LT" tire.
The steel cords have a larger diameter and greater tensile strength to meet the additional load requirements.


Load is load is load. If a non ST tire is rated at lets say 2800# and a ST tire is rated at the same 2800# what are the "additional load requirements" they are speaking about?

Oh, and now we are to replace trailer tires every 3 to 5 years? Thats a new one on me.

I like my Goodrich 225 75 R 16" LT tires, thank you.

[perryg114]

Funny thing is that if you look at the weight of a light truck passenger rated tire it is heavier than the same size trailer tire. The truth is that trailer tires are built cheaper and lighter and they increase the load capacity by derating the speed limit on the tire to 65MPH. Any tire will probably be ok for short low speed trips in cool weather. Most trailer tires will run hot and fail running down the road with the temps around 100F. Passenger rated tires will run all day and not fail under similar conditons. Tire companies don't care if your trailer gets ruined but they do care if they kill someone in a vehicle carrying passengers. I have never seen any definative test data that says that trailer tires are better for trailers than regular tires.

Perry

Originally Posted by idroba

I don't understand these statements:


"ST" tires feature materials and construction to meet the higher load requirements and demands of trailering.
The polyester cords are bigger than they would be for a comparable "P" or "LT" tire.
The steel cords have a larger diameter and greater tensile strength to meet the additional load requirements.


Load is load is load. If a non ST tire is rated at lets say 2800# and a ST tire is rated at the same 2800# what are the "additional load requirements" they are speaking about?

Oh, and now we are to replace trailer tires every 3 to 5 years? Thats a new one on me.

I like my Goodrich 225 75 R 16" LT tires, thank you.

[Protagonist]

You need to look at the entire rating on the tire, not just the first part.

Example: ST195/60R15 87S
ST = Special Trailer (other possibilities are LT = light truck, P = passenger, and MS = mud and snow)
195 = Width of tire tread in millimeters
60 = ratio of height to width
R = Radial (other possibility B = bias ply)
15 = diameter of rim in inches
87 = load index - the higher, the better. For a four-tire trailer weighing 5000 pounds (for example), the minimum acceptable would be 89, since that's the lowest number that supports 1250 pounds or more per tire. Trailer tires will tend to have higher numbers (and support more weight at a higher psi) than passenger-car tires, all else being equal.
S = Speed range. The higher the letter, the better. Minimum for a trailer tire should be L if you take the trailer up to highway speeds; speed range L is maximum 75 mph, meaning that you're at risk of overheating the tire running it on the interstate. I'd personally use speed range N (87 mph) or higher for interstate travel, and preferably speed range Q (100 mph) or better for long-distance interstate travel.

There are also P-metric, P-euro-metric, LT-metric, and ST-metric tires, that use different labeling schemes, based on the number of belts in the tire and the maximum cold-inflation psi, but I won't go into those.