Broken Cord on Michelin Tire

[Henry Jay Hannigan]

Neil:
After reading about everything on tire inflation, the only result I
can see with inflating to the max indicated on the sidewall is a
BUMPIER ride and better gas mileage. If Max Load to Max air is
safe, it seems that max air to less than max load would be just as
safe unless you have an example........I know the BUMPY ride part....
I'm just a hard headed old fart!

take care..
Regards,
Hank
90SP36 at 120PSI
Honda accord at 35PSI
the max on the sidewall for each tyre











--- In WanderlodgeForum@yahoogroups.com, "Neil & Pat"
wrote:
>
> Hank, there is no question that under inflation is significantly
more
> harmful (and dangerous) that over inflation. However, as I listed
in my
> earlier response there are numerous problems with over inflation
including
> some which potentially dangerous or expensive or adversely affect
ride
> comfort. Note the maximum pressure on the sidewall is the correct
pressure
> only when the tire is loaded to the maximum load also shown on the
sidewall.
> In your case you obviously have gotten by with operating at the
maximum and
> have accepted whatever negative that procedure brings. I sincerely
hope
> that your good luck continues into the future.
>
> Regards,
> Neil
> Author, The Rver's Ultimate Survival Guide
> http://www.rvsafetyinfo.com
>
> -----Original Message-----
> From: WanderlodgeForum@yahoogroups.com
> [mailto:WanderlodgeForum@yahoogroups.com]On Behalf Of Henry Jay
Hannigan
> Sent: Tuesday, September 09, 2008 9:55 AM
> To: WanderlodgeForum@yahoogroups.com
> Subject: [WanderlodgeForum] Re: Broken Cord on Michelin Tire
>
> NEIL:
> Aint it safest just to fill air to whatever MAX it says on the
> tire????? Anyway...that's what I've done on my BIRD and my car for
> umpteen years.......
> Regards,
> Hank
> 90SP36
>
> PS I have 12R22.5 Bridgestones on the BIRD and Goodyears on the
> Honda toad.
>
> --- In WanderlodgeForum@yahoogroups.com
> , "Neil & Pat"

> wrote:
> >
> > Hi Pete, David, Greg, Randy and all else who have been following
> this
> > thread. You called for a tire engineer to make input into this
> subject;
> > well I have been doing that for 36 years now and also happen to
own
> and
> > operate a Wanderlodge (PT-36 ) for the past 12 years and have
> written
> > extensively on the subject of RV safety in my book on the subject
> as well as
> > respond to many of the tire questions posed on this and other
> forums.
> > Perhaps I can help.
> >
> > The original question was re: a broken belt (actually shifted) on
a
> Michelin
> > tire with the thought was this a problem on the Michelin tires and
> would it
> > be subject to warranty. At 27k miles the tire problem in question
> is
> > almost certainly the result of a "road hazard" either a rock,
> shoulder drop
> > off, hitting a curb or possibly even improper usage of "chocks"
for
> leveling
> > or other purposes. Had it been a manufacturing problem it would
> have shown
> > up much before that time. You did receive proper advice in that
> this is not
> > a warrantable condition by the manufacturer but often dealers do
> provide
> > "road hazard" protection as a service to their customers.
> >
> > This is one of the major differences between truck tires and those
> used on
> > automobiles; in order to carry heavy loads much higher pressures
> are used
> > and the tire is normally operated at a lower deflection rating. On
> trucks
> > the deflection of the sidewall when normally inflated is on
average
> 8% by
> > design when it is properly inflated for the load carried, in
> contrast on an
> > automobile tire the deflection is approximately 12%, thus,
yielding
> a
> > smoother ride and a tire less susceptible to impact loads as
> mentioned
> > above. For your interest aviation tires actually operate at 32%
> deflection
> > to carry the immense loads involved but do so with a duty cycle
> limited to a
> > few seconds. The "hoop strength" of the belt package" is under
> immense
> > tension from the inflation of the tire becoming more and more
rigid
> and
> > unyielding as pressure goes up making the tire much more critical
> to this
> > type of abuse. So for our RVs we have a quandary, RVs are the only
> vehicles
> > on the road, which operate at 100% of the capability 100% of the
> time making
> > their safe operation somewhat precarious. We must carry the
> correct (high)
> > amount of air pressure to carry the load (at the correct
deflection
> rate)
> > but should not exceed that pressure or operate below the required
> amount.
> > Higher pressure than required will yield decreased steering power,
> braking
> > power, higher impact type damage as well as decrease life; too
low a
> > pressure will result in over deflection, hotter running
temperatures
> > (possibly destructive), poor handling, greatly reduced life and
the
> > potential for catastrophic premature failure. Take your pick, but
> none of
> > these options are very appealing to me.
> >
> > The above realities of life is the reason why the tire
> manufacturers, the
> > RVSEF and myself all repeatedly attend and lecture at rallies and
> anywhere
> > RVers gather to spread the word that RVs are different and incur
> > considerably more operator responsibilities from the
> owner/operators. It is
> > absolutely essential that you have your RV weighed properly wheel
> by wheel
> > to assure that none are overloaded and then and only then
determine
> the
> > correct pressure for your specific RV under the conditions you
> operate it.
> > Plain and simple there is no other way.
> >
> > Always happy to be of assistance:
> >
> > Neil LeKander
> > Author, The Rver's Ultimate Survial Guide
> > http://www.rvsafetyinfo.com
> >
> > less likely to crush to the wheel rim, possibly protecting the
tire
> > from pinching damage, but the high pressure would also place the
> tire
> > under tension pressure ... so???
> >
> > Any tire engineers out there?
> >
> > Pete Masterson
> >
>

[Hisham Amaral]

David Enjoy Los Wages and watch your dollars. Lots of people think they can beat the house, that will never happened. That is way they can afford to castles using your dollars and mine. Have a nice trip back home. Best regards, Hisham and Sue Amaral 97 WLWB 43 W. Bloomfield MI --- On Wed, 9/10/08, David Brady wrote: From: David Brady Subject: Re: [WanderlodgeForum] Re: Broken Cord on Michelin Tire To: WanderlodgeForum@yahoogroups.com Date: Wednesday, September 10, 2008, 1:42 PM Thanks Hisham, That's great information. We're still working our way back home; currently in Las Vegas. Gonna be 95deg F today, better get the sweaters. Glad you had a great trip and hope to meet up one of these days. Best, David, Suzana, and Danny '02 LXi, NV Hisham Amaral wrote: > David > > I found this link to be very good at answering some of the question I > had about truck tires. I would like to share it with the group. Please > discard if it is an information overload. > Hope that your trip to the West Coast was good and enjoyable, our was > the best ever. We will meet at one of the riles some day soon. > > http://www.goodyear .com/truck/ pdf/radialretser v/Retread_ All_V.pdf > <http://www.goodyear.com/truck/pdf/radial...All_V.pdf> > > Hisham & Sue Amaral > 97 WLWB 43 > W. Bloomfield, MI > > --- On *Tue, 9/9/08, David Brady //* wrote: > > From: David Brady > Subject: Re: [WanderlodgeForum] Re: Broken Cord on Michelin Tire > To: WanderlodgeForum@ yahoogroups. com > Date: Tuesday, September 9, 2008, 1:39 PM > > Thanks Neil, that helps a great deal. Glad to see you here > on this list. Just a couple of questions: > > 1) can I measure "deflection" ? > 2) does "deflection" change as the tire rotates at speed? > 3) sounds like the sole purpose of tire pressure is to maintain > the correct deflection? > 4) if I were able to dynamically adjust runtime tire pressures, > would optimum tire life/performance be achieved by maintaining > the correct deflection under all ambient operating conditions? > > Thanks, > David Brady > '02 LXi, LV > > Neil & Pat wrote: > > > > * Hi Pete, David, Greg, Randy and all else who have been following > > this thread. * You called for a tire engineer to make input into this > > subject; well I have been doing that for 36 years now and also happen > > to own and operate a Wanderlodge (PT-36 ) for the past 12 years and > > have written extensively on the subject of RV safety in my book on the > > subject as well as respond to many of the tire questions posed on this > > and other forums. Perhaps I can help. > > > > The original question was re: a broken belt (actually shifted) on a > > Michelin tire with the thought was this a problem on the Michelin > > tires and would it be subject to warranty. At 27k miles the tire > > problem in question is almost certainly the result of a “road hazard” > > either a rock, shoulder drop off, hitting a curb or possibly even > > improper usage of “chocks” for leveling or other purposes. Had it been > > > a manufacturing problem it would have shown up much before that time. > > You did receive proper advice in that this is not a warrantable > > condition by the manufacturer but often dealers do provide “road > > hazard” protection as a service to their customers. > > > > This is one of the major differences between truck tires and those > > used on automobiles; in order to carry heavy loads much higher > > pressures are used and the tire is normally operated at a lower > > deflection rating. On trucks the deflection of the sidewall when > > normally inflated is on average 8% by design when it is properly > > inflated for the load carried, in contrast on an automobile tire the > > deflection is approximately 12%, thus, yielding a smoother ride and a > > tire less susceptible to impact loads as mentioned above. For your > > interest aviation tires actually operate at 32% deflection to carry > > the immense loads involved but do so with a duty cycle limited to a > > few seconds. The “hoop strength” of the belt package” is under > immense > > tension from the inflation of the tire becoming more and more rigid > > and unyielding as pressure goes up making the tire much more critical > > to this type of abuse. So for our RVs we have a quandary, RVs are the > > only vehicles on the road, which operate at 100% of the capability > > 100% of the time making their safe operation somewhat precarious. We > > must carry the correct (high) amount of air pressure to carry the load > > (at the correct deflection rate) but should not exceed that pressure > > or operate below the required amount. Higher pressure than required > > will yield decreased steering power, braking power, higher impact type > > damage as well as decrease life; too low a pressure will result in > > over deflection, hotter running temperatures (possibly destructive) , > > poor handling, greatly reduced life and the potential for catastrophic > > premature failure. Take your pick, but none of these options are very > > appealing to me. > > > > The above realities of life is the reason why the tire manufacturers, > > the RVSEF and myself all repeatedly attend and lecture at rallies and > > anywhere RVers gather to spread the word that RVs are different and > > incur considerably more operator responsibilities from the > > owner/operators. It is absolutely essential that you have your RV > > weighed properly wheel by wheel to assure that none are overloaded and > > then and only then determine the correct pressure for your specific RV > > under the conditions you operate it. Plain and simple there is no > > other way. > > > > Always happy to be of assistance: > > > > */ Neil LeKander /* > > > > */ Author, The Rver’s Ultimate Survial Guide /* > > > > */ http://www.rvsafetyinfo. com /* > > > > less likely to crush to the wheel rim, possibly protecting the tire > > from pinching damage, but the high pressure would also place the tire > > under tension pressure ... so??? > > > > Any tire engineers out there? > > > > Pete Masterson > > > > > > ------------ --------- --------- --------- --------- --------- --------- ------ > > > > No virus found in this incoming message. > > Checked by AVG. > > Version: 7.5.524 / Virus Database: 270.6.17/1655 - Release Date: 9/5/2008 > 7:05 PM > > > > > > -- > No virus found in this outgoing message. > Checked by AVG. > Version: 7.5.524 / Virus Database: 270.6.17/1655 - Release Date: 9/5/2008 7:05 > PM > > > ------------ --------- --------- ------ > > Yahoo! Groups Links > > > > > > > ------------------------------------------------------------------------ > > No virus found in this incoming message. > Checked by AVG. > Version: 7.5.524 / Virus Database: 270.6.17/1655 - Release Date: 9/5/2008 7:05 PM > -- No virus found in this outgoing message. Checked by AVG. Version: 7.5.524 / Virus Database: 270.6.19/1664 - Release Date: 9/10/2008 6:00 AM ------------------------------------ Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/WanderlodgeForum/ <*> Your email settings: Individual Email | Traditional <*> To change settings online go to: http://groups.yahoo.com/group/WanderlodgeForum/join (Yahoo! ID required) <*> To change settings via email: mailto:WanderlodgeForum-digest@yahoogroups.com mailto:WanderlodgeForum-fullfeatured@yahoogroups.com <*> To unsubscribe from this group, send an email to: WanderlodgeForum-unsubscribe@yahoogroups.com <*> Your use of Yahoo! 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[erniecarpet@...]

Neil, can you guys come to our Lone Star rallies and give a seminar?

Ernie Ekberg
83PT40
Livingston, Montana

---

Psssst...Have you heard the news? There's a new fashion blog, plus the latest fall trends and hair styles at StyleList.com.

[Neil & Pat]

Hi David, thanks for your interest in this very important topic.

In response to your questions, please consider:

1) Yes you can measure deflection but it is not easy to do with precision.
Deflection is the "change" in section height and can be measured in the
footprint (bottom) side of the wheel/tire as installed by taking the
distance from the road surface to the metal rim and comparing that to the
same measurement on the "unloaded" portion of the wheel/tire (top). That
figure, when expressed as a % change should be very close to a nominal value
of 8% for truck tires.
2) Yes the above measurement of deflection would change at speed due to the
centrifugal forces action on the unloaded portion of the tire. However,
deflection is a "static" measurement intended to be taken in a laboratory
environment not as we drive.
3) Your are once again correct, deflection of the tire is the ultimate
limitation for a tire because that is the primary factor in creating heat
thus effectively limiting the weight carrying capability of the tire.
4) In normal service there is no need to be concerned about the dynamic
effects of deflection or any other variability i.e. altitude, ambient
temperature changes, barometric pressure, etc. these issues are all fully
considered by the tire designer when the tire is first designed. It is then
fully tested to verify the accuracy of that work. All that remains is for
the tire builders to get it right and for the operator to do the right thing
by following the load/pressure charts provided by the manufacture and of
course avoid all the road hazards out there. Easy right?

Hope all this helps a little.
Regards,
Neil
Author, The R.Ver's Ultimate Survival Guide
www:rvsafetyinfo.com
Thanks Neil, that helps a great deal. Glad to see you here
on this list. Just a couple of questions:

1) can I measure "deflection"?
2) does "deflection" change as the tire rotates at speed?
3) sounds like the sole purpose of tire pressure is to maintain
the correct deflection?
4) if I were able to dynamically adjust runtime tire pressures,
would optimum tire life/performance be achieved by maintaining
the correct deflection under all ambient operating conditions?

.