Brian Beker
Hi, Everybody - 

The other day I was backing my 177SE into a spot when the angle of the sun highlighted the inboard tread on the driver's side tire in the rear view. It looked bizarrely deformed and scalloped and it was badly worn. The tire on the other side wasn't as bad, but displayed the same symptoms.

I took the trailer to a tire shop the next day and the mechanic identified the problem as tread separation. He showed me some other (not Corker) tires with the same problem—but that weren't detected before they blew out. Not encouraging. They really BLEW out.

The only tires in stock that would fit the wheels were were a set of Nobles—never heard of them till then—but at least they're steel belted and rated for 2050 pounds each instead of the Corker nylon 1750-pounders on the trailer, which means they're at their limit when the trailer is at max—which I believe these trailers will be hard pressed not to be.

I'm camping in the Idaho mountains and don't have the bandwidth to upload a video of the knowledgable mechanic explaining how to diagnose the problem, but in it, he shows how the little indentations (they look like tiny slits or dashes, you'll see them) in the rubber in the center tread of the tire disappear every few inches. When the tread separates, and the centrifugal force of the separated tread forces parts of the tread outward and wears it harder on the road, the parts that are separating show more wear, and so those dashes disappear every foot or so. So, as you turn the tire you see dash-dash-dash then bald spot then dash-dash-dash and bald spot, and so on.

Beware. This could have turned into a bad situation. The Corkers my 177 SE was equipped with are insufficient for the load, meeting only the maximum gross weight, especially since I'm starting to think that the factory never weighed these units. Normal practice is to overdo it at least a little with tires, equipping cars, trucks and trailers with ones that exceed the load limits of what they're carrying. After all, do you blow a balloon up juuuuust to the point where they're ready to burst...?

You will notice that on your weight stickers (the yellow one inside the door and the one near the front of the driver side of the trailer, the actual empty weight of the trailer is never stated. All it says is that maximum weight is 3500 and that cargo, which includes water, should never exceed 520 pounds. That would mean that the trailer should weigh 2980 empty. I have my doubts, based on what might not have been an accurate weighing following this tire event, but, even if that empty weight number is correct, the Corkers are designed only to accommodate the max gross weight, and that's not enough.

I had the bearings removed and inspected and repacked. They were okay. The problem was with the Corkers.

I don't blame Riverside for this event, though the question about the accurate empty weight of the camper is concerning. And I don't think they ought to be suppluying those flimsy Corkers. The tire guy told me that though the tires appeared to be defective, they were too cheap to pursue a warranty claim, because he said the manufacturers would want them shipped at my expense, and would then pro-rate. I would have come out behind.

I didn't keep an accurate mileage on those Corkers, but I'd guess they made it to somewhere in the 15,000 mile range.
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mikes
Coker, not Corker.

A trailer loaded to 3500 lbs should have no more than 3150 lbs on the tires, the rest would be tongue weight (at least 10%). The Cokers are rated at 1770 each. But they're also passenger car tires, so they are being pushed near the limit.

What you describe sounds more like cupping, not tread separation. Here's a discussion on RV.net.

15,000 miles really isn't bad for trailer tires. According to Discount Tire, "The mileage expectation of a trailer tire is 5,000 to 12,000 miles."
Mike
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AJ
Good info, Thanks for posting that. I remember the dealer stressing that I maintain the proper air pressure and that the tires weren't cheap. I've had that trailer up to 80 mph. I am concerned about a blow out. I'm definitely gonna keep an eye on that. Thanks! 
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Nathan N Jen Cooper
For replacements look into diamond back tires.
They offer a 3 inch white wall in a trailer tire..
A trailer tire will get you increased capacity. The question then becomes can the axle handle it..
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V & T
What tire pressure should I be running on my 177SE? The dealership said 35psi. The tire sidewall lists the max weight rating at 32psi. We are leaving soon traveling about 350 miles per day. Thanks in advance.
Van & Terri
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mikes
You should never exceed the maximum pressure indicated on the sidewall. For the Coker H78-14's, that's 32 PSI (cold). You can expect them to measure more than that after they've been driven a while and heated up.
Mike
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Alabama Jim
I could not even read the make of tires on my 2016, 195 Retro, they appeared to be made in China.  They wore poorly, one was bald and the others had 1/4 indention on the inside edge of the tread.  I replaced them with Maxxis tires after seeing that a large number of RV owners recommend them.
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Robin C
After reading all the posts on this thread, I got new tires for my 166 - Trailer King, I believe. They're 6ply steel radials made for trailers. I didn't get the ones with white walls (too expensive), but I figured it's better to be safe than pretty. Now I just have to decide what to do with my Coker white walls.
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Alabama Jim
Our 195 came with bias tires and the indentions were caused by the belts sliding to the side.  The Maxxis tires we got are steel belted radials.  The other forum I read suggest that in number 2 place is the Goodyear Marathon.
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Notactingmyage
The original bias ply tires on my 166 were excessively worn (nearly bald) on the outsides of the tread and showed very little treadwear on the insides after less than a year and only 4,000 miles.  I thought that might be indicative of a bent axle or alignment problem and had everything laser checked at a qualified trailer shop.  They found nothing bent or misaligned, and attributed the abnormal wear to "cheap bias ply tires."  I replaced the polyester bias ply tires with Trailer King steel belted radials and had the bearings repacked.  I only have 700 miles on the new tires so it's too early to assess how the radials will ultimately perform, but so far there is no evidence of abnormal wear.

BTW, I sent photos of the worn tires to the Riverside folks who promptly reimbursed the full cost of parts and labor for this issue under the initial one year warranty with no questions asked.  I'm pleased with their support.
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A.J.

I am on the hunt for tires.  I see the Diamond Back white walls as an option.  We are traveling cross country this summer.  Would we better off getting the Endurance tire, or do you guys think the Diamond Back would suffice.  This is a 7 week, 8 to 9 thousand mile trip.

I want the best tire possible.  I would love to keep the white walls but will forgo them for safety and peace of mind if needed..

Thank you for any advice you can offer.

A.J.

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amxpress
I’ve had success using Maxxis M8008ST tires. 3 campers with never a tire failure. They’re a quality ST tire from an established tire manufacturer that’s been around for a long time. Be sure your new tires are balanced. 
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