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RustyJC's avatar
RustyJC
Explorer
May 14, 2016

ST225/75R15 Trailer Tires

First of all, please forgive me for intruding in the TT forum, but I need to help out some friends. They have a TT that came from the factory with cheap Chinese Brand X (she didn't say) ST225/75R15D tires, and they've had 3 tire failures on one trip. I really can't tell you what they did insofar as inflation pressure, speed, load, etc. are concerned, but I told them that I'd seek the advice of the experts to find them a decent quality replacement tire. My knee-jerk reaction is, at a minimum, to move up to a Load Range E tire if their wheels are rated for the 80 PSIG pressure, but what say you about brands that have a chance of giving them better service?

Thanks for your help.

Rusty
  • Too many people jump on the country of origin as the primary cause IMO. Without knowing the exact history of how the tires were treated over their lifetime, you have insufficient data to make a judgment. With ST tires, it is so very important to never tow under-inflated or overloaded and to stay under 65 mph. Irreversible internal heat damage will be a result and is cummulative. Also avoid hitting speed bumps and potholes at speed and stay off road shoulders.

    Some TT manufacturers install tires with almost no reserve load capacity which in itself is not good and then, one or more tires could be overloaded because weight is not evenly distributed between all 4 tires. It is a worthwhile exercise to go to a scale with any TT and get weights on all 4 tires when the trailer is fully loaded. What is the trailer's GVWR?

    The loss of 3 tires on one trip is highly suggestive of either improper care/treatment or picking up road debris or both. Was it "blowouts" or punctures and how old are the tires? As already mentioned, other contributing factor(s) could be an axle problem. Loose wheel bearings can also damage tires. I've read of a few cases where the manufacturer welded the spring hangers in the wrong location, causing the tires to track wrong.

    A big contributing factor in ST tire failures in my mind is that nobody tells you how to treat ST tires when you buy a TT. The dealer says nothing, there's nothing in the owners manual or package, no warning stickers - nothing. It's not until owners go onto an RV forum that they learn about ST tires. I would say TT buyers generally have an expectation that trailer tires are like tires on cars & trucks, but they're just not.

    Going to a higher load range tire or LT tire may be the thing to do, but I believe you should get the weights on all 4 tires so you can make an informed decision. Maxxis gets good reviews but are not immune to failures. We have Marathon LRD and are good 2 seasons and about 10K miles later - our TT would have come standard with LRC tires and now we have very good reserve load capacity. A TPMS is a very good investment, and while it won't warn of an imminent blowout, it will warn you of a slow leak.
  • without more info regarding their weights, pressures etc., it's difficult to make an educated suggestion.

    I am looking to replace our OE tires before heading out west again. I went to the tire store and spoke with a tech yesterday and have decided upon Carlisle Radial Trail RH LRD

    I have a fairly light trailer and I'm stepping up to 225s so that will give me more capacity in itself, but stepping up to LRD is even more.

    In my case, he feels I don't need to go up to the newer 225/75r HD which are LRE, in which the pressure is 80#. If these folks wheels would hold that pressure that would be my suggestion if the weights are in line.

    This guy is a tire salesman, but he said the Carlisle RH & the HD lines are the best trailer tires he's seen in 15 years he's been in the bidness. I guess time will tell.

    My first thought would be that these folks have overloaded the TT, or run the tires low on air, but that's just a guess.
  • 1. you are correct at looking into wheel psi ratings , to match the new tires pressure rating and width are often overlooked. There is some wiggle room , but i'm not too sure about 80# E tires on 50/65# rims.

    2. 3x ? you might have another problem other than China.

    I would have a 'tire expert' ( I know, that's a loose term) inspect the tires to see .....road hazard or heat related.
    If one blew then the spare blew on that same wheel , then I would think something is wrong and NOT a road hazard.
    It might be overloaded on one of the axles creating a heat issue ?
  • Just speculation.
    3 failures on the same trip makes me also wonder that maybe they hit/ran over something?

    Good advice from the posters above. On the trailer we just sold, we had Maxxis E's and had great service from them...but ANY tire be it ST or LT and any brand is still subject to a failure.
  • We are looking at replacing all four of our TT Tires. It's not necessarily the "China Bombs" described in many threads. If your tires are failing make sure you check the axle(s) for alignment and if the problem is the tire it may be a 6 ply tire. Move up to an 8, 10 or even 12 ply tire to eliminate excessive outside wear or blowouts. Trailer King make a good 10 ply Radial in the size you asked for. Made in China but a well made one.
  • If your friends tires are still on warranty and proven defective, they should receive compensation. I did on a new trailer.

    Maxxis are good but usually special order and not available everywhere.

    If I needed tires today, I would consider these: Carlisle 225 75R 15 E
  • Rusty,

    The topic of tires always produces lots of posts - sometimes contentious.

    Personally, I think part of the problem with tires on travel trailers is not enough load carrying capacity - so your idea to go to a Load Range E is the right direction. But a more complete solution would be to going to 16" tires and wheels.

    Many people will point to converting to LT tires - but they forget that this type of change doesn't involve a simple exchange. You have to change size and that complicates matters.

    But to answer your question about tire brand: Some folks point to Maxxis, however, there are some reports of failures, making this recommendation somewhat questionable.

    And lastly, you should emphasize to your friends to weigh their trailer - and if they don't weigh each wheel position, they have to account for side to side and front to rear weight variation. My recommendation is that the tire should not be loaded to more than 85% of its rated load.

    Further, they should be reminded that ST tires have a 65 mph speed restriction.

    Hope this helps.
  • Any brand sold by a reputable dealer will do. I had a set of Goodyear Marathons that were on my trailer when I bought it used and in good shape. I put 15,000 miles on them in the last 15 months including trips to Baja and north to Alaska.

    I finally had to replace them NOT because of the tires but because my worn suspension wore one tire badly and I replaced all four...they were ELEVEN years old.

    The MOST commmon casue of tire failure is underinflation and since it happened to 3 tires on one trip that would be my guess.

    I replaced my Goodyears whith a set of Towmax of a higher load rating and 80psi vs the 65 of my Goodyears.

    Most tires come with road hazard protection...a good reason to buy them from a nationwide dealer...and some level of treadwear gaurantee pro-rational replacement.

    Try not to listen to those on this site with Axes to grind about a specific tire brand or where they are manufactured. ALL tires sold in the US are manufactured to DOT and stricter international standards despite where they are made.