Busboy

One of my kids just bought an older 5th wheel fitted with the ST205/75D/15 tires, It's getting close to 50 years ago I last used a belted tire but I seem to remember the tread was flat. All 4 tires look the same but the tread is not flat and has a very pronounced radius to them. if it wasn't for the fact all 4 tires are identical I would say that the belts have let go. Anyone have any input???

torquefan

I bought a used trailer a few years back with those on it. I think they were some horribly cheap off-brand. The trailer hadn't ever been pulled far, but to me they looked like they had uneven wear, tread looked "too rounded" like you mention. I was pretty uneasy about them, and of course it didn't take long for one to blow out on the road. Replaced them with ordinary ST205/75R15 trailer tires and haven't had another issue. It sounds like you're uneasy about them, I'd consider replacing them.

Busboy

Thanks torquefan I am "uneasy" about them, they just don't look right. I'll suggest they replace them right away.

KATOOM

If you ever find yourself with nothing to do for a few days, research ST trailer tires. Then sit back and read threads..... You find that the topic is VERY heated and will generally result in passion rivaled only by "which oil to use" threads.

That said, just to inform you, ST tires are supposed to be designed differently than P or LT tires. They supposedly have different compounds to offset heat dissipation, have stronger sidewalls for more load support, have no capacity reserve like P and LT tires, have a common tread design, and.....very important to know is that they "time out" at 5 years and are not supposed to be aged based on tread depth.

In defense of that last statement, you can run them as long as you choose as I often run them much longer than that but you just have to watch the tread to casing areas because they'll start to crack and then thats when the tread will peel off at an inopportune time.

Lastly, within the heated debates, its considered that the biggest problem with ST failures is that people have a bad habit of parking their trailers and not moving them for a looooong time. Then the tires dry out and when you go to move them their structural integrity is not as strong.

Oh yeah, some ST tires will have a "bowed" look to the tread. Thats normal depending on the tire but typically more so on the smaller lighter capacity tires.

Busboy

Thanks KATOOM good to know about the bowed tread on smaller ST tires. I took one off and inspected it as they all looked good just the bowed tread. The date stamp was 3514 so about 2 years old, as the kids don't have much money they are going to try them, they did drive about 260 miles at hi speed with them after they bought the trailer so there is that to consider also. I use 16 inch ST radials on my 3 dump/flat/skidsteer trailers which don't usually do long distances but my RV has 16 inch Michelin LT XPS ribs on it which I'm very pleased with. We recently did a 1200km plus trip to the East coast through the Northern US states and the XPS ribs still look good.

KATOOM

Another thing for your kids to check on (which it sounds like you're knowledgeable enough for them) is to make sure of the tire weight ratings for their trailer weight. Its terribly common for trailer manufactures to install tires which are under rated or just at their capacity.

Because I'm no fan of tires falling apart on the road and tearing everything up, I run a TPMS. Very handy.

bigredbrick

Not only will they install tires that are underrated but will do the same with axles. I had to replace the brakes on my '94 Kit and found that parts were hard to get so I replaced the whole axle and brake assemblies, surprisingly cheap. The originals were 2500 lbs (it was years ago so I might be a little off), the replacements are 3500 lb for a 6200 gross travel trailer. Previous owner had upped the tire size from 205 to 225. I still have 2 ancient Tow Masters, one on the ground and one for a spare. Keep the tires covered when stored.

sojoe

Get rid of those ST tires-They will let your son down and cause damage when(not if) they BLOW.
Dealers love to sell ST tires and claim you don`t want to use LT tires-They are brain washed by the tire mfg`s.
ST`s SUCK.
Sorry to be so blunt, I have had many st`s come apart-.A lesson learned.
Best of luck to your son

Mexstan

Read my last post in the thread just before this one.

Busboy

Just to update on those ST tires.. Daughter and son in law made their trip in the mountains using those tires, I truly expected a call to say they had blow some but nope all was good. His brother is in the trade and had seen those tires before he told him that's how they come new.. As for ST vs LT's I use Michelin LT XPS ribs on my RV but all my other trailers have ST's. I can buy a 16 inch new rim and tire mounted for $125 , the XPS ribs were over $300 just for the tire. When trailers are used in construction areas there is a lot of nail punctures so I keep 7 spare wheels and fix my flats myself. I usually wait until I have a few to fix but one of the last batch I fixed 4 nails then when I inflated it I found I missed a very small finishing nail. I junked it. ST tires have their place. Just read my last post on here where I said our trip was 1200km plus it was just over 12,000km.

RobG

I've had waaaay too many problems with ST type tires on my 5th wheel. I finally put 16" wheels and 225/75-16 tires (because that's all that would fit because the idiots at Keystone mounted the axles too close together to use anything bigger), Bridgestone Duranza commercial-type tires... because I couldn't afford XPS Ribs or the big bad Goodyear G6xx 14-plies.

Made a 2200-mile trip back in March and they did great.

Rob