age for tire replacement

[steelheadbluesman]

My Michelins say 3905. I bought the rig brand new from the dealer in mid-2007, virtually no miles. So, either the tires sat in a warehouse, presumably unmounted, or they sat mounted on the chassis, right? How old are they in the real world? 5, 6. or 7 yrs? Anybody's guess, I suppose....

Also. I'm curious about all those chunks of tread I see scattered all over the highways. Some are seriously large and even have 'belt' material in them. Some are strewn for a hundred yards -- I see them every time I travel. Blowouts? Lost retreads? I suspect the latter. The question of danger to others has been brought up... How dangerous are older tires on my MH, compared to retreads blowing apart on big tractor-trailer rigs?

Also, are there any real statistics on big-rig tire failures, causes, age, etc., or do we pretty much just have opinions here?

I know I'm asking a lot, but these safety issues are important.... Thanks, I'm open to any input.

[grafxman]

Does anyone know what this means:

DOT UPWY C3H

That's what's on the Cooper tires on the front of my MH.

[Coma]

Originally Posted by wb7auk

Well not really there are studies out there that say the total loss of any
rear tire or tires is worst case. On duals you have to loose both tires on
one side for this to be true. Has to do with the ability to add power to
correct drag.

I'd be interested in reading about that. Any links or sources I might look at?

[336muffin]

Originally Posted by steelheadbluesman

My Michelins say 3905. I bought the rig brand new from the dealer in mid-2007, virtually no miles. So, either the tires sat in a warehouse, presumably unmounted, or they sat mounted on the chassis, right? How old are they in the real world? 5, 6. or 7 yrs? Anybody's guess, I suppose....

Also. I'm curious about all those chunks of tread I see scattered all over the highways. Some are seriously large and even have 'belt' material in them. Some are strewn for a hundred yards -- I see them every time I travel. Blowouts? Lost retreads? I suspect the latter. The question of danger to others has been brought up... How dangerous are older tires on my MH, compared to retreads blowing apart on big tractor-trailer rigs?

Also, are there any real statistics on big-rig tire failures, causes, age, etc., or do we pretty much just have opinions here?

I know I'm asking a lot, but these safety issues are important.... Thanks, I'm open to any input.

When I was a Owner Operator, and owned truck and trailer I had very good luck with tires. I was careful not to bruise the sidewalls and so on. I ran from NC to west coast back to NYC back to NC. Averaged 44 to 46 trips per year, 49 was best for me. Nobody else drove the truck but me. I could average from 120,000 or more miles on a tire. Steer was different, those were rolled to the drive and new steers were bought. I never thumped them with a hammer or billy. I always sold the tires (carcus) and some times ran Bandags(cold cap) with no problems. 110 degrees through desert at some pretty good speeds with no problems. Some tires used to be capped many times in their life time. Some company drivers did not care to look at a tire , wasn't their job! In 5million miles I blew two steers and one trailer tire! There is a lot of reasons for "alligators" dead in the road. If you gamble with dated tires it can be very expensive! I have a friend with $12,000 worth of damage now from a blown steer.

[wb7auk]

Originally Posted by Coma

I'd be interested in reading about that. Any links or sources I might look at?

As I recall some where from the National Highway Safety branch of the
gov.

[travelgirl]

Howdy,

I agree with the other however don't forget to add dry rotting into effect when I forst bought my coach they were dry rotting great tread and low miles but I did not feel safe with the dry rotting so I replaced...($2280) later...Ouch the price we pay for owning expensive toys...lol

[SteveLevin]

I don't think there's a hard date range, but only you know how your tire has been treated.

Tires that I've put on new, I know I check tire pressures all the time with a tested gauge and will correct even a 2 or 3 lb low condition. I know if I've banged tires off something. I know my pattern of use (10 500 mile trips spread throughout the year are much better than, say, 1 5,000 mile trip), etc etc. I know that I will roll the coach so I can check the entire surface of the tire at least 4 or 5 times a year.

But when I buy a coach that's used and has older tires on that I don't know the history of... I get nervous much more quickly. When I see that rubber starting to dry up, my nervousness increases

900 miles into a long trip I decided my steers (8 year old Toyos) were making me too nervous and when I happed across a good deal for Michelin's in western Wyoming, I changed them. My drives are only 5 years old (and look better) so I'll leave them on for now, but probably change them right at the 7 year mark.

But that's me. Your risk tolerance may vary. The way I look at it, my fuel bills are a LOT bigger than my tire bills.

Steve

[Coma]

Originally Posted by wb7auk

As I recall some where from the National Highway Safety branch of the
gov.

I did find this. This study is directed at Motor Carriers but sourced from Motor Coach manufactures, too. Nothing personal here, for sure. The only reason I pursue this is my understanding of cause and effect of drag. The rears are much closer to the center of gravity than the steers so should have less effect. Although, I have been wrong before.

It indicates steer tire is worst case. It also notes dual tire mismatch in pressure causes problems, because of tire circumference difference. 5/16 of an inch diameter difference of 5 psi difference. Most notably, as we suspect nearly 80% of tire failure are due to under inflation. Tires and brakes are the cause of nearly 80% of accidents where there was a mechanical failure.

[wb7auk]

Originally Posted by Coma

I did find this. This study is directed at Motor Carriers but sourced from Motor Coach manufactures, too. Nothing personal here, for sure. The only reason I pursue this is my understanding of cause and effect of drag. The rears are much closer to the center of gravity than the steers so should have less effect. Although, I have been wrong before.

It indicates steer tire is worst case. It also notes dual tire mismatch in pressure causes problems, because of tire circumference difference. 5/16 of an inch diameter difference of 5 psi difference. Most notably, as we suspect nearly 80% of tire failure are due to under inflation. Tires and brakes are the cause of nearly 80% of accidents where there was a mechanical failure.

But the center of gravity can change in a moving vehicle.

[WeatherTodd]

Originally Posted by Old Trucker

I am a retired cross country trucker. I would not be afraid of the old tires on a city bus, WHY; how fast does a city bus travel????maybe 35 mph???So a tire blows, at these speeds I would not be alarmed as a driver or passenger. How far is a city bus from a tire shop... I agree these tires are plenty old, but in this application, I do not see a problem. the old trucker

but old trucker... the city bus will be carrying alot more passengers/weight than your typical RV.
But if "age" were a prime consideration... is the bus fleet manager taking that much of a risk? I would estimate the vehicle to travel 100 miles or more in a given day.

[CD]

Originally Posted by WeatherTodd

but old trucker... the city bus will be carrying alot more passengers/weight than your typical RV.
But if "age" were a prime consideration... is the bus fleet manager taking that much of a risk? I would estimate the vehicle to travel 100 miles or more in a given day.

I would question that a bus carries more weight compared to its GVWR than an RV. It has been proven that about 70% of Rvs are at or over their GVWR. Except at commute time I would bet that most city buses run at 50% or less of their load capacity.

[Coma]

Originally Posted by wb7auk

But the center of gravity can change in a moving vehicle.

You mean during a tire failure? To what effect?

[wb7auk]

In your post you indicate the center of gravity was near the rear wheels. That maybe
at rest but once underway depending on what forces are applied to the vehicle the
center of gravity can change a bunch.

[wb7auk]

Originally Posted by Coma

I'd be interested in reading about that. Any links or sources I might look at?

http://www.edccorp.com/library/TechRefPdfs/EDC-0021.pdf

This is one of the studies.
What you are interested in is near the end of the study