Tire design issue or something else?

Harks_723 · 12-16-2018, 07:30 AM

Morning everyone. First post here, I'll do an intro separately but I wanted to come on and get opinions on my Keystone Outback.

Long story short I have a 2017 Outback 324CG, single owner, purchased new in May of 2017.

Trailer weighed in full trim at 10,060lbs.

As I was leaving a friends after visiting for Thanksgiving we noticed what seemed to be 'bubbles' in the driver side rear tire. The unit is a dual axle.

Upon inspection, the inner tread (measured as to the centerline of the trailer front to back) is HEAVILY worn. The sidewall on half of this Trailer King tire is starting to bubble, indicating was I imagine is the tire ready to come apart. Luckily it was caught, I replaced with the spare and we made it back to our current home base in Albuquerque without issue.

The passenger side rear tire is also showing signs of tread wear in the same pattern.

Front tires look completely fine.

Doing a complete review I'm left scratching my head a bit on a few issues from a design standpoint.

The trailer king tires (factory issued) are marked as a MAX rating of 2,540lbs each. Combined that's 10,160lbs. However, Keystone has this trailer as a max GVWR of 10,500lbs. We remain under that weight (religious about not overloading).

Am I missing something?? I know there is safety factor in equipment, but how can the factory provide tires that are almost 500lbs underweight for the max recommendation for the trailer??

I brought the issue up to Keystone and they are recommending that I take the trailer in to have a rear axle inspection done to rule out it being bent. This is scheduled for Jan 2. Part of me thinks I'm being sent on a wild goose chase as the axle doesn't seem to be bent, the tires are not out of camber, and the wheels spin freely when off the ground.

I also asked Keystone for a formal statement on the tire selection logic regarding the max weights. This was two weeks ago. They are still remaining in contact but nothing has surfaced as requested.

I know the factory is going to put the bare minimum on as a way to cut costs. These tires have lasted us over a year with probably 14-17k miles, but it still seems like premature wear. If it's a case of the tires being overloaded, it doesn't surprise me, but per the book the trailer is not over weight. If anything, the tires are UNDER weight.

Thoughts/comments? Any help is appreciated. Tire pictures attached.

notanlines · 12-16-2018, 07:52 AM

First and foremost, you are badly "under-tire'd." Yep, I just made that up.

Very, very few experienced RV'ers across the board will give your China-bombs a thumbs up. You are well into borrowed time with these rags when you drive off the lot. I agree that the axle should be inspected. And then you should immediately re-tire! Maybe Maxxis, Carlisle, or Goodyear.

**JRTJH** · 12-16-2018, 08:25 AM

^^^ X2 what Jim said. Your tires "meet or exceed" (barely) minimum requirements to support the trailer weight by using "industry magic"...

What I mean by that is the manufacturers (all of them, not just Keystone) deduct the tongue/pin weight that is carried by the tow vehicle from the trailer weight and "magically endorse" that the axles are only carrying what's left....

So, with your trailer GVW of 10,500 pounds, assuming 1000 pounds is tongue weight, that leaves 9,500 pounds on the axles. Divided by 4 tires, that's "ONLY" (yeah right) 2375 pounds per tire, so your LRD tires " easily have 165 pounds of "excess capacity" as a "safety reserve".... Again, yeah right.....

As Jim said, you're "grossly under-tired"....

Your best bet: Have the axles checked, if they are good (probably are unless you've had an accident or hit a significant pot hole) and then get new tires that are "upgraded beyond the load range D (8 ply) tires" that are currently on your trailer.

I'd recommend 225 75R15 LRE tires. Brand is up to you, but the three "currently favorable tires" in the order most chosen by most members are:

1. Maxxis M8008
2. Carlisle Radial Trail HD
3. Goodyear Endurance.

The Goodyear Endurance has a good track record so far, but has only been on the market about 18-24 months, so there is no "long term real use data" other than manufacturer testing. So far, it looks good but nobody can tell you what the performance will be in the 3-4-5 year use cycle.

By choosing the 225 75R15 LRE tires, each tire will have a capacity of 2830, an increase of 290 pounds per tire position for a total increased capacity of 1160 pounds. Without changing to 16" wheels, the LRE tire option is about your best bet.

Rest assured, you're not alone in your tire issue. RVIA changed tire safety reserve capacity in the new RVIA standards and has partly (not completely) improved tire capacity. While that does nothing for trailers built before the standard changed, at least it's a step in the industry fixing a long time problem.

Here's what the inside of my TK tires looked like at 24 months of use. A time bomb waiting to happen and no way to see the tread separation without dismounting the tire to see inside. At least, in your situation, you were able to see the problem and resolve it before a disaster. Some weren't (or won't be) so lucky....

ChuckS · 12-16-2018, 08:27 AM

I’d have to UP the load range from that current D tire to an E in same size. Maxiis 8008 or perhaps the new GY Endurance.

Bottom line is you are on borrowed time with hose remaining tires and an increase to load range E in any tire except Trailer King or Towmax would be
Money wisely spent now...

Wait and it will cost you more when next blow out comes with those other D rated tires.

CWtheMan · 12-16-2018, 02:16 PM

According to the specs for your trailer it was fitted with those LRD tires before the new 10% load capacity reserves were applied by Keystone. A LRE in the same tire size designation will get you above the 10% reserve recommendations.

Tire sizes/load capacities for RV trailers are determined by the trailer’s vehicle certified GAWRs. Check your certification label. Your vehicle certified GAWRs are somewhere between 4800# & 5000#. Remember, it’s not what the label on the axle says; it’s the official GAWR on the vehicle certification label.

The short way to figure out what your GAWRs are is to deduct the published tongue weight 985# - from the GVWR - 10,500# = 9,515# and divide by 2 = 4,757#, that's the minimum legal load capacity to be set for your axles. Divide that by two and add 10% and you will have the minimum load capacity for tires, using the RVIA recommendations.

Almost all of the ST tire manufacturers have added the LRE to their ST225/75R15 designated size line-up. One has added a LRF, requiring 95 PSI and new wheels. But, it’s steel cased and probably more durable.

From looking at your pictures I'd venture to guess they were under inflated or grossly overloaded. Without knowing their history you have to change all of them or risk trailer damages only your insurance will cover.

Harks_723 · 12-16-2018, 06:20 PM

Thanks for the help guys. I've already looked into the Maxxis tires you've mentioned. Discount tire has them for not too bad of a price, I think just over $100 and change mounted and balanced.

Keystone had mentioned a warranty or reimbursement from Trailer King on the "faulty" tires... Anyone actually ever get paid by them?

Considering the miles I've put on this rig I suppose I've gotten much more than others have. Glass half full viewpoint.

Quote:

Originally Posted by CWtheMan

From looking at your pictures I'd venture to guess they were under inflated or grossly overloaded. Without knowing their history you have to change all of them or risk trailer damages only your insurance will cover.

Thanks for the reply. I can assure you that before every transit pressures (and lugs) are checked. As far as "gross overload" on weight, I offer that there could be some deviation from my weighed 10,060lbs but nothing beyond 500lbs... Which still puts me where the max specs are.

**JRTJH** · 12-16-2018, 06:35 PM

Quote:

Originally Posted by Harks_723

...
Thanks for the reply. I can assure you that before every transit pressures (and lugs) are checked. As far as "gross overload" on weight, I offer that there could be some deviation from my weighed 10,060lbs but nothing beyond 500lbs... Which still puts me where the max specs are.

Keep in mind that ST tires "degrade with age" at about 10% per year. At least that's the generality of how to determine degradation. So, hypothetically, if your trailer is a 2017, it could have been built as early as March 2016 and the tires could have been manufactured in late 2015, so that would make them 3 years old in December 2018. Ten percent per year comes out to 30% about now..... Hard and fast rules ?? Nope, but a general guide to remember when it comes to figuring how much is "left in your tires". Most RV'ers say that they replace the tires at 4-5 years and they always replace tires that still look like new....

Conceivably, your current tires could have a max weight capacity of 2540-30% (762 lbs) or to say it another way, they could have degraded to a maximum capacity of around 1778 pounds..... Yet another reason to not tow next season on your current tires.

Harks_723 · 12-16-2018, 06:58 PM

Quote:

Originally Posted by JRTJH

Keep in mind that ST tires "degrade with age" at about 10% per year. At least that's the generality of how to determine degradation. So, hypothetically, if your trailer is a 2017, it could have been built as early as March 2016 and the tires could have been manufactured in late 2015, so that would make them 3 years old in December 2018. Ten percent per year comes out to 30% about now..... Hard and fast rules ?? Nope, but a general guide to remember when it comes to figuring how much is "left in your tires". Most RV'ers say that they replace the tires at 4-5 years and they always replace tires that still look like new....

Conceivably, your current tires could have a max weight capacity of 2540-30% (762 lbs) or to say it another way, they could have degraded to a maximum capacity of around 1778 pounds..... Yet another reason to not tow next season on your current tires.

Great info here. I'm glad I posted the question.

Luckily I'm full timing. Even more lucky, we're work camping until March, so I've got plenty of time to change them. I'll keep the thread updated with Keystones involvement on the issue.

CWtheMan · 12-16-2018, 02:31 PM

Did it again, double post.

Rber1234 · 12-17-2018, 04:20 AM

In my opinion ST duty tires are a joke for what they have to do..The very first sign of a problem or as soon as I possibly can this spring I’m switching my tires out to LT rated tires..

Snoking · 12-17-2018, 05:30 AM

Quote:

Originally Posted by Rber1234

In my opinion ST duty tires are a joke for what they have to do..The very first sign of a problem or as soon as I possibly can this spring I’m switching my tires out to LT rated tires..

Given that trailer manufactures build to ST tires inflated weight ratings, one has to be careful in choosing a LT to replace a ST tire. With 15" rims that offen means switching to 16" rims.

**JRTJH** · 12-17-2018, 08:52 AM

Quote:

Originally Posted by Rber1234

In my opinion ST duty tires are a joke for what they have to do..The very first sign of a problem or as soon as I possibly can this spring I’m switching my tires out to LT rated tires..

Good luck finding LT tires in the 15" wheel size. (don't even consider P rated tires). Actually, the tires on your trailer are 205 75R15 LRD rated at 2150 per tire. You could easily install 225 75R15 LRE tires from a "quality manufacturer" and obtain an additional 2720 pounds of tire capacity. That's significantly more "weight capacity" than you'll find with any 15" LT tire.

Nearly 3000 pounds of increased capacity on a trailer weighing 4900 pound..... You do the math and cost analysis.....

68GS400 · 12-23-2018, 09:12 AM

Rber1234
Some TT tires sizes are not available as LT. Our Passport Ultralite comes with 205 75 14 LR C tires. Only option is LR D as upgrade. None of the nationwide sources list LT rated tires

jadatis · 12-23-2018, 01:59 PM

The kind of wear on one side indicates an alignment problemm.
This can be because of hitting something, but when I look at picture of your TT hiched up, I see a verry low towbarr so buttum up.
This lifts up the rear axle.

In Europe are some most single axle trailers profided with a Delta- axle, wich give toe in or out alignment when lifted or pushed down.

Placing your towbar higher and / or using a weightdistribution hich, gives straighter TT so both axles in the middle.

I dont know if these Delta-axles are also used for tandem axle TT , but you could find out if so .

Further I enlarged the tire picture and read next
ST225/75R15 8PR 113/108L loadrange D
Maxload 2540lbs AT 65 psi. 8PR is the European eqivalent of D-load.
L is speedcode for maxspeed 120km/75m/ h.
For that speed the maxload is calculated.

If Delta axle I would try to upgrade to LT in E or F-load. Then first follow the advice of Tireman9's post and weigh and take enaugh reserve.
This kind of wear is more if tires deflect more.

Harks_723 · 12-23-2018, 06:20 PM

Quote:

Originally Posted by jadatis

The kind of wear on one side indicates an alignment problemm.
This can be because of hitting something, but when I look at picture of your TT hiched up, I see a verry low towbarr so buttum up.
This lifts up the rear axle.

In Europe are some most single axle trailers profided with a Delta- axle, wich give toe in or out alignment when lifted or pushed down.

Placing your towbar higher and / or using a weightdistribution hich, gives straighter TT so both axles in the middle.

I dont know if these Delta-axles are also used for tandem axle TT , but you could find out if so .

Further I enlarged the tire picture and read next
ST225/75R15 8PR 113/108L loadrange D
Maxload 2540lbs AT 65 psi. 8PR is the European eqivalent of D-load.
L is speedcode for maxspeed 120km/75m/ h.
For that speed the maxload is calculated.

If Delta axle I would try to upgrade to LT in E or F-load. Then first follow the advice of Tireman9's post and weigh and take enaugh reserve.
This kind of wear is more if tires deflect more.

Thanks for the reply.
Attached is another photo of the rig setup, the truck for sure squats but I think that other photo exaggerated the "tail up" look.
We do run a w/d hitch - Husky centerline

I'll have them check alignment when they do the axle review Jan 5.

Typically 68mph is our average cruise speed when towing. Never over 75 even when passing.

Again loads of great info here. Thanks everyone.

Tireman9 · 12-23-2018, 06:43 PM

Quote:

Originally Posted by Harks_723

Thanks for the reply.
Attached is another photo of the rig setup, the truck for sure squats but I think that other photo exaggerated the "tail up" look.
We do run a w/d hitch - Husky centerline

I'll have them check alignment when they do the axle review Jan 5.

Typically 68mph is our average cruise speed when towing. Never over 75 even when passing.

Again loads of great info here. Thanks everyone.

The bubbles/bumps on the inside are evidence of separation. not an alignment issue

You said the RV weighed 10,060# I assume that is the total scale weight for 4 tires.

ST tires loads are calculated based on 65 mph max operating speed (see your owner's manual) tires if in PERFECT balance only have 25# margin assuming your pressure gauge is accurate +/- a couple psi. and you NEVER started traveling without confirming pressure and have NEVER added any weight since getting the RV weighed.

You have not told us the age of the tires or why you think you have a perfect axle to axle and side to side loading.

What does your owners manual tell you to do to confirm weight and inflation?

Have you read my signature or qualifications from my RV tire blog?

Did you read the post on why tires fail?

Gapopper · 12-23-2018, 06:45 PM

I once had three blowouts on one leg of a trip. I have learned a lot about tires since then. You can’t skimp on quality when it comes to tires. I replace my tires every three years no matter how good they look. I run E rated tires. I also keep the tires off the ground when stored. I purchase my tires from Amazon. I have had good luck with the tire age when they arrive. The date code has been 2 to 6 months old on all the tires that I have purchased from Amazon. You have to be careful purchasing from a dealer too. If the tires have been sitting on a shelf for a couple of years , their life clock has already started ticking down. You want the freshest tires that you can get for your camper. I also purchased TPMS to Monitor the tire pressure and temperature while towing. If a tire starts to lose pressure , you will hear an alarm. This gives you time to pull over before the tire damages your camper.

wiredgeorge · 12-17-2018, 09:43 AM

Discount Tire normally has the Carlisle Radial Trail HT in stock and on hand; that is why I almost always use them. If you decide to go with the Maaxis ST tires, call ahead and make sure they get them in the store. Either brand is certainly a slightly better choice than the OEM tires.
As far as the tire wear, even the china-bombs that were installed should not have worn as they did. I do suspect a bent axle. Keep in mind that axles should have a slight bow facing upwards and not be straight as they are fitted on the trailer. I think your dealer is right to have to make that appointment to check that axle as the tire wear is NOT due to the crappy nature of the OEM tires. (my amateur opinion which doesn't count much on RV tech issues).

Snoking · 12-17-2018, 10:29 AM

My Discount store had many sets of GY Enderance ST225/75R15E's in stock.

crossdr · 12-23-2018, 08:57 AM

First thing is have your axles aligned. You probably need to do both because specialists are reluctant to just do one. Immediately replace all your tires with E rated.

I have an 06 Raptor, and have had no end of tire trouble. I have had the axles aligned three times, I have replaced a broken axle and I replace tires regularly. After talking to many tri-axle trailer owners, I would never purchase another tri-axle, and not sure I would buy a Keystone product given all I have seen and heard. I helped the tire issue by replacing all with E rating tires but still replace 2 or more per year. I carry two spares. I have found no brand better than others. I have used Good Year, Carlisle which are crap, and several others. The best I have found so far are the Tire King house brand E rated.

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