Tires look flat. Max pressure is 32psi.

[scooper77515]

I have a single axle trailer for my 18.5' boat, heavy Glastron.

The 14" custom rims have tires on them from previous owner, that list max pressure of 32 psi, but at 32, they look flat from all the weight, and drag while towing.

I need some tires that I can inflate to 45 or more to stiffen them up for easier towing and that don't look flat with boat on them. And be within the tires' specs for safety.

Any suggestions for better rubber?

 

[Gary H NC]

Re: Tires look flat. Max pressure is 32psi.

If they call for 32 psi they are car tires.
You need a set of ST rated trailer tires.They will be rated for at least 50 psi.

 

[Gary H NC]

Re: Tires look flat. Max pressure is 32psi.

I have run these tires for years and they hold up very well.They sell just the tire without the rim.

http://www.northerntool.com/shop/tools/product_200330258_200330258

 

[xeddog]

Re: Tires look flat. Max pressure is 32psi.

If your existing tires are car tires, they are most likely radial ply too. Trailer tires are usually bias ply which give you a much stiffer sidewall. The stiffer sidewall will reduce the side-to-side sway more and give you a more stable tow.

Wayne

 

[dingbat]

Re: Tires look flat. Max pressure is 32psi.

If they call for 32 psi they are car tires.
You need a set of ST rated trailer tires.They will be rated for at least 50 psi.

Not necessarily. I have General ST 205R14 trailer tires that are rated #1430 @ 32 psi.

 

[MTboatguy]

Re: Tires look flat. Max pressure is 32psi.

I used to run into this same problem when I was in the RV business, quite often when people would replace tires on their trailers for one reason or another, they would get passenger tires, which are designed with a good ride in mind..

Air pressure is not as important as tire construction when dealing with trailers and the loads they carry, you need to go to a tire shop and explain what your towing with weights and let them recommend the correct tires for your set up. Make sure and tell them the max weights, not just a dry boat on the trailer, you have to take into account the fuel, the equipment, the ice chests and anything else you might be carrying.. Also, make sure your load is balanced when towing, it is just as important as it is when your on the water..

When towing trailers with any weight on them, and using passenger tires the trailer can become unstable at speed, I have seen 24 foot travel trailers flipped on their sides, because of the wrong type of tire on them. One other thing to keep in mind, when you change to trailer tires, make sure and change the spare as well, so that you have matched sidewall stiffness and strength, I have seen miss matched set ups really cause problems in ride, towing stability as well as braking capabilities...

 

[scooper77515]

Re: Tires look flat. Max pressure is 32psi.

Alright! At least I know what I need to look for.

I am sure these are just car tires. Soft sidewalls, lots of squish and swim when I drive. And sucking my gas mileage down bad.

And with the sidewalls flexing and squishing so much, I bet I am building up TREMENDOUS heat and just asking for a blowout on my next long hot haul.

 

[MTboatguy]

Re: Tires look flat. Max pressure is 32psi.

Alright! At least I know what I need to look for.

I am sure these are just car tires. Soft sidewalls, lots of squish and swim when I drive. And sucking my gas mileage down bad.

And with the sidewalls flexing and squishing so much, I bet I am building up TREMENDOUS heat and just asking for a blowout on my next long hot haul.

Check your sidewall coding numbers and you should be able to figure it out real quick, just copy the information down and search the net, and you will find charts as well as the decoding of those codes on the sidewall, that will tell you exactly what you have on your trailer.

 

[scooper77515]

Re: Tires look flat. Max pressure is 32psi.

Since I am getting good answers...

Boat weight is 2750, not sure of trailer weight (EZ Loader galvanized, single axle).

The ones I am looking at new, 50 psi bias ply trailer tires, have max capacity 1760 lbs.

Do I double that weight with boat and trailer, or can I take into account that the trailer hitch is taking some of that weight?

What weight capacity do my tires need to be able to handle?

Thanks in advance, guys. Getting good answers and guidance

 

[burp]

Re: Tires look flat. Max pressure is 32psi.

Scooper,

Most 14" trailer tires are load range C. As you found out max capacity is usually around 1760 lbs per tire, or 2x1760=3520 lbs. for a single axle trailer.

You state that your boat weight is 2750 lbs. Most likely that is dry weight (ie: no gear or gas.) Gas weighs about 6.25 lbs per gallon. A single axle trailer will be around 800 lbs or so. So the boat and trailer alone will be around the 3520 lbs that the load range C tires are rated to carry. Sure you will subtract from that weight the tongue weight on the trailer hitch ball which should be less than 500 lbs if you have a class 3 trailer hitch. But remember the weight of the gas, oil and gear will add up quickly.

Since you would be close to the maximum weight that the tires are rated to carry, I'd look at/for load range D tires. The only 14", load range D tires that I have located are Kumho 857's. Look at www.tirerack.com for more info on the Kumho's.

http://www.tirerack.com/tires/tires.jsp?tireMake=Kumho&tireModel=Radial+857

 

[MTboatguy]

Re: Tires look flat. Max pressure is 32psi.

Actually at the weight levels you are looking at, I might be inclined to clean the single axle up and start looking for a duel axle trailer.

Of course I am very careful when it comes to towing, I have seen far to many tragedies in my years in the RV business.

Just wondering, do you have brakes on this trailer?

That's just my opinion of course..

 

[scooper77515]

Re: Tires look flat. Max pressure is 32psi.

Nope, no brakes. This is the trailer that sold with the boat. Has GLASTRON all over it.

Luckily, I tow 4 miles to the boat ramp, so no long-distance. But even short distance on these 32 psi tires, I can feel my truck struggling (5.7 hemi).

PS--saved the kumho page on the tirerack site. They look perfect!

 

[MTboatguy]

Re: Tires look flat. Max pressure is 32psi.

Nope, no brakes. This is the trailer that sold with the boat. Has GLASTRON all over it.

Luckily, I tow 4 miles to the boat ramp, so no long-distance. But even short distance on these 32 psi tires, I can feel my truck struggling (5.7 hemi).

PS--saved the kumho page on the tirerack site. They look perfect!

As I said,

I am very cautious when it comes to towing and I probably over compensate, but with a short haul like that, I would still upgrade the tires to at least give you the peace of mind.

Just be careful..

 

[cribber]

Re: Tires look flat. Max pressure is 32psi.

Just a thought... first chance ya get change out the car tires for trailer rated rubber. 50 psi will definitely improve your handling and road feel over 32 psi.

 

[scooper77515]

Re: Tires look flat. Max pressure is 32psi.

Yep, looking at kumhos with 50 psi rating. Will order them this week.

 

[gozierdt]

Re: Tires look flat. Max pressure is 32psi.

I just ordered the D range Kumho's that Burp recommended a couple of weeks ago. Really a nice looking tire, haven't towed any long distance with them yet, but the sidewalls are nice and stiff, and tread looks good. Be sure to check that your existing wheels will handle the extra load of a 50 psi trailer tire. I went ahead and ordered these wheels "TW-GBWS1465SG 14 inch Galvanized Steel Spoke Trailer Wheel 5 on 4.5 Lug Pattern - $39.99", from
trailer-wheels.com, because my old wheels were pretty rusty, and I didn't want to trust them.

 

[burp]

Re: Tires look flat. Max pressure is 32psi.

The Kumho load range D tires need to be run at 65 PSI to handle the maximum load for which they are rated for. A lower air pressure results in a lower maximum load.

 

[scooper77515]

Re: Tires look flat. Max pressure is 32psi.

Can they be installed at Discount Tire or any of the auto tire installers, or do they need to be installed with a special machine.

Mine are currently on fairly nice rims, but if it will cost extra to drive to a special place, I may buy them already on a rim.

 

[burp]

Re: Tires look flat. Max pressure is 32psi.

Any tire shop can install them.

 

[Gary H NC]

Re: Tires look flat. Max pressure is 32psi.

Discount tire installed all 4 of my trailer tires and balanced them....around 40 bucks i think.
You are doing the right thing stepping up to a higher load range tire.
I had a 19 ft Starcraft I/O on a single axle trailer and always thought it was too much.