Difference in trailer tires..

thatguy · Mar 24, 2006

What is the pluses/minuses between 7:00 x 14.5 (8 ply) and ST 225-75/R15 (8 ply) trailer tires.. I think one is a bias and the ST is a radial, but other than that what about long life, durability, etc. etc.

I always thought that most trailers running the 7:.00 x 14.5 were using Mobile Home tires.. But I see that Hudson trailers offers new trailers with them..

Just curious..

thanks

Brian

kossetx · Mar 24, 2006

Here is my opinion, and it's just that. I feel that radials on my trailer are not used enough. It mostly just sits, sometimes for a long time. I think the belts rust and I have a lot of blowouts with them. Bais tires don't seem to give me that problem as much.

rdln · Mar 24, 2006

I have been messing with 14.5 demountable rim tires for awhile, and have found pluses to be:

diameter to load rating ratio is low so trailer can sit closer to ground

... and thats about it.

minuses:

people see you with those and think you are breaking the law and that you are cheap for using mobile home axles and tires (which in my case is not true)

the local tire guy does not a have pile of trailer quality used ones lying around.
the same is true for the rims.

I have had heavy duty and light duty versions of DOT app. tires, the HDs are pretty darn good but light duty tread wears out to quickly.

extra attention needs to be given to mounting and retorking (sp!)

I have bought brake parts from a hudson dealer therefore if the brake shoe thickness is the same on hudson's as mobile home axles,
they are made for limited use only.

After my experience with these. I would not buy nor recommend buying demountable 14.5" tired trailers

RobS · Mar 24, 2006

Don't know if this is true or not but I've heard that real trailer tires (with a "t" in the size) are formulated to avoid dry rot and such from lack of use. Seems to make sense as most trailers sit far more than passenger vehicles.

/forums/images/graemlins/smile.gif

Farmwithjunk · Mar 24, 2006

( Don't know if this is true or not but I've heard that real trailer tires (with a "t" in the size) are formulated to avoid dry rot and such from lack of use. Seems to make sense as most trailers sit far more than passenger vehicles.

/forums/images/graemlins/smile.gif )

Sometimes I think my trailer moves more that the truck I use to tow it /forums/images/graemlins/frown.gif) Well, maybe not THAT bad.

Trailer radials (the GOOD ONES anyway) have a slightly different sidewall construction (than passenger car or truck tires). They get dragged sideways sometimes when making sharp turns. I've actually broke 2 tires off the bead while jack-knife turning a long gooseneck trailer. Front axle was literally sliding sideways.

After blowing both right side trailer tires at the same time last summer, I'm all in favor of buying the best trailer rubber money can buy. (65 MPH in door handle-to-door handle traffic when they blew out) They take a thrashing. (Both tires still had over 2/3rds of the original tread left. It was "carcass failure" [probably from running slightly UNDERinflated] that did them in. Weight and tire size called for 85 to 95 psi. I ran 75. POW!) After "post-blow-out inspection" it was noted that there was a definate seperation of plies taking place. Tire tech showed me "ripples" in the sidewall that indicated there was eminent danger of the other 2 blowing out.

Consider the fact that MOST trailers don't have shock absorbers. That makes the tire and the trailer frame soak up all the impacts that "70 MPH down the road" can dish out.

Highbeam · Mar 24, 2006

"Consider the fact that MOST trailers don't have shock absorbers. That makes the tire and the trailer frame soak up all the impacts that "70 MPH down the road" can dish out."

Pretty sure that most trailers have springs to absorb impacts. The shock just prevents bounces, right.

HammerFour · Mar 24, 2006

I have been thru several trailer tire failures, most of them seem to die from sun exposure, which leads to cracking and 'weather checking'. The tires then tear apart at some point ( usually during hot weather and under load ).

I replace the ones that look bad, some of them just come apart without much or any warning.

I think some of those RV tire covers might be handy to put on the tires to prevent from UV and weather damage.

Farmwithjunk · Mar 24, 2006

Springs "absorb" weight. They TRANSMIT shock through to the trailer frame. When you hit something that would compress the springs, where do you suppose THEY hit the trailer? At the SPRING PERCH on each end of the springs. Shock absorbers do EXACTLY whattheir name implies. They absorb SHOCK. Without them, the shock load is distributed throughout the suspension and on to the trailer frame.

ronjhall · Mar 24, 2006

A shock absorber on a vehicle is kind of improperly named. It's purpose is to keep the tire in contact with the road.

George2615 · Mar 24, 2006

Trailer tires are built stronger than passenger car tires. They have stiffer sidewalls, are built stronger, and are more resistant to cuts / bruising. They are built stronger because they spend more time being dragged during sharp turns than a regular tire. ST stands for Special Trailer. all trailers should run an ST tire which can be bias or radial. Most tires you see that are 7-14.5 are mobile home rated only and state so on the sidewall. There are tire companies that make 7-14.5 tires for trailers with the ST on the sidewall. Usually the numerical size tires are bias ply instead of radial. ST trailer tires are also usually more expensive than regular passenger tires.

Egon · Mar 24, 2006

shock absorber

Some folks call them "Dampers"

Egon /forums/images/graemlins/grin.gif

thatguy · Mar 24, 2006

I didnt make myself clear, but I was specifically asking about 7 x14.5 tires that are approved by DOT for Highway use... I has always thought you could only get these tires for 'mobile home use only', but obviously if Hudson is selling new trailers the tires have to be approved for such..

thanks for the feedback..

brian

Farmwithjunk · Mar 24, 2006

The contractor I work for has a couple lowboy trailers with the 14.5" tires. They're highway approved, NOT mobile home tires. Not that common, but available apparently

Farmwithjunk · Mar 24, 2006

( "Consider the fact that MOST trailers don't have shock absorbers. That makes the tire and the trailer frame soak up all the impacts that "70 MPH down the road" can dish out."

Pretty sure that most trailers have springs to absorb impacts. The shock just prevents bounces, right.

)

According to Monroe, the people that make a large percentage of modern shock absorbers, they dampen shock released by the springs as a reaction to sudden compression or de-compression. Springs will not "absorb" impact shock. They only re-direct it The energy that a spring absorbs is released when the spring rebounds. Shocks, as a result of absorbing that impact, keep tires in good contact with the road, as well as takes away some of the recoil effect of the spring that would also be sent through the vehicles frame.

Springs and/or tire sidewalls don't offer the smooth dampening effect that a hydraulic shock can.

Bird · Mar 24, 2006

( I have been thru several trailer tire failures )

Me, too. /forums/images/graemlins/frown.gif On the round trip to Alaska and back in '72 with me pulling a travel trailer, my parents pulling a travel trailer, and an aunt and uncle with a pickup camper, we experienced 17 flat tires. /forums/images/graemlins/tongue.gif Then my '89 fifth-wheel trailer came with ST (trailer) tires, but they were bias ply. I made it all the way to Anchorage with it in '90, but found when I got there that two of them had big bubbles in the sidewalls. I believe the first radial trailer (ST) tires were made by Goodyear in '89 or '90 and I put them on the fifth-wheel when we got back south. Goodrich came out with their own radial ST tires in '91 while I was back in Anchorage working at my brother's tire dealership. Personally, I wouldn't even consider bias ply tires on anything that was going to be used very much because the radials will last enough longer that they're cheaper in the long run.

rdln · Mar 25, 2006

Thats the way it goes here, Brian. Hijacked threads is a risk you take.

In my post I was referring to DOT approved Powerking brand LOWBOY tires
but I have to add the more favorable HD version only came in 8-14.5 still you cannot find a 2800 lb load tire thats as small as a 14.5.

Oh did I mention to buy american or canadian made tires /forums/images/graemlins/laugh.gif /forums/images/graemlins/wink.gif /forums/images/graemlins/shocked.gif /forums/images/graemlins/smile.gif /forums/images/graemlins/grin.gif /forums/images/graemlins/blush.gif /forums/images/graemlins/grin.gif /forums/images/graemlins/blush.gif /forums/images/graemlins/smile.gif

ronjhall · Mar 25, 2006

My previous trailer was a 14' Hudson tandem axle. It had 14.5 tires on it. Here is a link to a place that sells the tires. Click Here They are used to give a lower trailer.

Ramairfreak98ss · Mar 26, 2006

which tires are the ones that are like max psi of 100psi? My trailer was bought used, no rated weight, well it was on paper as 2000lbs lol but i guess the builder did that for registration purposes, the previous owner had a 9400lb loader on it a few times and he said it rode great.

My 3600lb car doesnt put a dent in what this thing can haul, its a 16ft long dual 7k axles open car or equipment trailer.

My dumbarse was pulling the car around with 40~ psi in the tires till i realized my 91 f150 was really struggling on highways to pull this thing along lol, Here it should be at at least 60+PSI for 3000lbs or more. I tested the used tires to 85psi and they seemed fine just rode hard for the weight on it at the time.

Ive seen other 5200lb dual axle 24ft enclosed triailers that have "car" looking 15" tires?