Blown tire

[BrucePerens]

Agree with Jampcourt that the sidewall PSI is for inflation of a non-rolling tire, and puts you at the low end of a pre-engineered pressure range for operation. Under-inflation has its problems.

I am not at all clear that blowouts are caused by over-pressure alone, unless it is really far out of range. Puncture, shock, severe under-pressure, brake or bearing binding, de-lamination and wear I would believe.

I suspect the rudimentary suspension plays a role in the shock issue.

[Padgett]

You left out imbalance. It is as important to have a trailer wheel tire balanced as a car tire. More so because you will not feel vibration and there is no shock absorber to dampen.

So under pressure & overloaded leads to heat and heat is what caused most failures (when racing on stock tires I once had the tires melt into the pavement and each had to be jacked up before the car could move).

That said I commonly used to autocross with 33 psi tire inflated to 50 psi. Cracked the centers out of wheels from gee forces but never had a tire failure.

[Keith Wire]

Originally Posted by [email protected]

once you have started down the road for about 30 minutes the tires will heat up (especially during the summer) and the tire pressure will go up as well. Depending on the load they could gain as much as 10 psi, which will put you at 75 psi.

Tom, I never saw more than a 2 or 3 pound increase in pressure when driving in the summer heat. Morning temps were 65 degrees and I would drive all day, on a hot day where the temps were 95-100 and my TPMS never showed the 10 psi change you are referring to.

Has anyone else seen this much change?

Keith

[RottieMom]

Jampcourt, that's my understanding too. That recommended psi is for cold. Anyway, what I've found is that all my various tire pressure gages aren't that consistent and my TPMS says my pressure was about 62 cold and if I remember correctly on my last trip the pressure got up to about 70 on the road. So, overall, I think I'm ok.

[RottieMom]

Keith Wire, I'm not going to swear the psi on mine changed by 8psi, but next trip, I'm going to note how much they did change. Was going from memory (which isn't is good as it used to be). Maybe it was more like 67 or 68 when tires were hot.

[BrucePerens]

It appears that we get more temperature change from the trailer brakes than from rolling resistance. The temperature goes up when we stop. I saw tires inflated to 65 go to 70 psi and 118F, at about 85F ambient. We were probably driving too fast.

[ShrimpBurrito]

Originally Posted by Keith Wire

Tom, I never saw more than a 2 or 3 pound increase in pressure when driving in the summer heat. Morning temps were 65 degrees and I would drive all day, on a hot day where the temps were 95-100 and my TPMS never showed the 10 psi change you are referring to.

Has anyone else seen this much change?

Keith

Yes, although in my experience, the increase in PSI is directly related to ambient air temp. The hotter it is outside, the greater the PSI increase, even in the tire that is in the shade. Makes sense, since I wouldn't be surprised that the road surface ends up getting warmer than air in extreme heat (as in 100 F+).

Dave

[[email protected]]

Originally Posted by BrucePerens

It appears that we get more temperature change from the trailer brakes than from rolling resistance. The temperature goes up when we stop. I saw tires inflated to 65 go to 70 psi and 118F, at about 85F ambient. We were probably driving too fast.

If you were in California, you were probably driving too fast no matter how fast you were going. I once saw a slug pulled over by a CHiP's officer that was issuing him a ticket!
Tom

[[email protected]]

Originally Posted by BrucePerens

Agree with Jampcourt that the sidewall PSI is for inflation of a non-rolling tire, and puts you at the low end of a pre-engineered pressure range for operation. Under-inflation has its problems.

I am not at all clear that blowouts are caused by over-pressure alone, unless it is really far out of range. Puncture, shock, severe under-pressure, brake or bearing binding, de-lamination and wear I would believe.

I suspect the rudimentary suspension plays a role in the shock issue.

I know for a fact and thru experience first hand...heck, both hands that a rim that is good for 65 psi will not hold pressures very much over that...like 72 psi, which is what I had in my tires when it blew. Before we left I checked the tire pressure and sure enough air had leaked out on the trip down to Port Aransas...so I filled them to 70 psi before we left Port A and half way home the pressure dropped and then KABOOM!...so I know what happened. Since then I have gotten stouter rims and NO air loss what so ever on my 5500 mile trip last fall!
Tom

[tentcamper]

If they are bias ply tires you will get a huge temp swing. To thr point that they will burn you hand.

Our normal swing with radials is about 5 degrees. But I have seem as much as 15 degrees on a very black asphalt highway.