Explanation for Trailer Tire Tread that is Convex Rather Than Flat

Updated 07/25/2024 | Published 08/16/2014

Question:

I have power king towmax. ST225/75R15s. They are less than 2 years old and have about 4,000 miles on them. One delaminated. and came apart from itself. When I put on the spare that was bought at the same time you an clearly see the tires on the trailer are very rounded and taller than the spare. These are load rated E. I always keep the tires at max pressure and check them with 2 gauges. What is happening? Thank you

asked by: Rob E

Expert Reply:

I consulted with our resident tire expert, and we're both at a loss. Heat build-up caused by over or under inflation, overloading the tire or failing to observe the speed rating of the tire (65mph in most cases) are the typical causes of premature tire failure.

When you describe the tires as being 'rounded', I'm assuming that you mean that the tread portion of the tire is convex, rather than being flat so it makes full contact with the pavement. Over-inflation usually causes this, but you state that you use two tire gauges to maintain the tire pressure to the full pressure listed on the tire sidewall, as recommended which would tend to rule out over inflation.

So now we're kind of grasping at straws... Perhaps your tire gauges have been dropped a time or two, and aren't very accurate any more. Maybe the tires you purchased last time were from a bad batch. You mentioned that all the tires were purchased at the same time... Were they all the same model and from the same manufacturer?

Perhaps if you could reply with a photo of the tires, showing the rounded tread, we might be able to come up with something more definitive. If you'd care to send some, we'd be happy to look at them.

expert reply by: Mike L