The most common cause of blow outs is running with an under inflated tire. I've seen many people here say they have had one and check their tire pressure religiously everyday yet have NEVER seen anyone check tire pressure at a campground.
A bit off topic but I've looked at quite a few motorhomes being sold by owner and it doesn't seem like a lot of folks change oil much either....
Due to ultra violet rays from the sun and other factors, the strength of tires deteriorates over time and they become dangerous. I don't know that five years is a magic figure, but something in that range is. A friend of mine blew the left front tire (six years old and properly inflated) on his 40 ft dp. It wrapped around the steering mechanism and put the coach on its side in a ditch. I have had several other friends have blow outs with tires that were around that age that were proeprly inflated and had lots of tread on them.
I realize that Michelen is in business to sell tires,b but their recommendation is to replace the tires around six years regardles of lack of tread wear.
Another reason tires blow out on motorhomes is lack of use. Driving on a tire works the plasticizer around the tire. It normally leaches away from the outside layer, even without UV exposure. Driving replaces it. But most motorhomes sit around undriven most of their lives. This is very hard on the tires, especially the spare if it is not used by rotating it with the front tires.
...This is very hard on the tires, especially the spare if it is not used by rotating it with the front tires.
However, given that my MH tires will be replaced based upon age and NOT wear and tear, I do not worry about any tire rotation at all. I figure it will cause more problems than it cure.
As for my spare, I consider it an emergency spare only. I do not replace it with age or worry about it. I only count on it getting me the the next tire shop to replace the blown tire, should that happen.
In my case, I man now replacing (next week) my original Firestone Steeltex with Michelin XPS Ribs with the brass dually tire valves kit from Tire Man (Chuck Carvitto). It was not quite time to do this, but an upcoming 8,000-mile trip inspired me to err on the side of extra safety.
I will not replace my Michelin's for 7 years (maybe more, though that starts to be pushing the envelope, perhaps). Note that Michelin does not seem to recommend replacing them by age alone, but by inspection for defects (small cracks) caused by age.
I think I will take your advice, HiTech, and inflate the inners 2 psi less than the outers, so that my inners will be 75 psi (per the weight load/inflation tables) and my outers 77 psi. This is a slight reduction from the 80 psi I am at now - I wonder if I'll notice any difference? Not a fair test, really, since I am, at the same time, comparing my old to new tires.
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edited 05/07/06 10:57am by Westronics *
I blew my right side outside tire a few weeks ago near Melbourne FL. I was going about 68, a loud bang, smoke and rubber was flying. Minor damage but thanks to Progressive, we were back on the road in about 45 minutes. I run with 85lbs and the tire man said the tire was 5 years old and that was the life of the tire. Hard to believe when it looked like new. The wife spent some time cleaning out her pants. :-)
HiTech...Does any tire manufacturer recommend that practice? I think not. We often travel on roads (depending on the lane in some case) with no crown.
see their streaming video on tire care
if we keep our tires only five years, and they don't get alot of miles, even with everything else mentioned above why would they "blow"?
1. I just watched Michelin's tire care video, and the only thing I saw was that if the dually tires have slightly different tread depths (there's a small allowable difference), the deeper tread (less wear) should be on the outside tire. Did I miss something?
2. Tires should never, ever "blow" if they are taken care of properly except possibly for some road hazard causing the failure.
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edited 05/07/06 11:13am by Westronics *
I have actual stats on the inner / outer pressure vrs. heat.
Michelin does suggest a small variance is acceptable. I used a Fluke Infra red gun to test tire temps on my new XPS Ribs last summer and set my dual pressures so the tires were the same temperature at tread center. This is based on the fact that although running lighter now I am still one of the biggest "C's" you can get on a E-450. We use it that way.
To do this I run 80 psi on the outer and 76 psi on the inner dual. This puts my traveling summer temps from 125 to 145 degrees but balanced between the two tires. Where as before the inner tire would run 10 degrees hotter almost always. The drivers side is not a similar situation. They run the same temp so I set their psi the same. I would not state this is typical and your results may vary.
The exhaust side Duals run almost 10-20 degrees hotter than the drivers side duals. Could be the exhaust, the drive tire stress, or coach design. This year I am making some ducting to scoop air and blow on/up into the inner dual and wheel well area. I have Alcoa's now as well and this may or may not make a difference in temps. I have no data without them.
I REFUSE to have another (now up to 4) tread peel, 12 ga Kaboom.
This is what I have done. We will see. If 245 series tires would fit I would run them instead of all this garbage.