Michelin blow out

[Rkesselus]

Being new to this site I have been amazed at the number of post I have seen talking about what good tires the Michelin are for RV's. I have been in some sort of Motor Home for 47 years. I have in that time period I have had 3 sets of Michelin and have had three front time blow outs. I have used a number of so called low quality cheep tires and the only flats period were the 3 on the Michelin. Two of the Blow outs were tires in warranty and I had to do battle with the Dealers and wound up going to distributors for resolution. Ask why I had three sets well it like this first problem shame on you, second problem shame on me, Third problem I won a raffle that included wheels and tires I should have kept the wheels and peddled the tires. I am currently on Hercules. A lot of investigation led me to them. Made by Cooper in the USA for large trucks and RV's. You know when people post is mostly about something bad that the are angered about. So just thinking out loud I see post about Michelin problems but not so much about other tire brands.

[JDL]

I have only been in the MH business for 18 or so years, but this is something I have noticed. At one time Goodyear was a very popular brand on RVs and we heard a lot of Goodyear issues.

Since those days, I have noticed that all of the DPs that I look at come with Michelins. If you take into account that the majority of the new coaches for that last 8-10 years come with Michelins, and probably more than half of the FMCA members (86,000) are running Michelins, coupled with one model of tire that was notorious for failure, you will hear about more Michelin failures than any other, as they are the prominent tire by the numbers on today's RV. What is interesting, is the Michelin tires are the only tire, my distributer will pay me back on when I replace to put into "trailer service".

I have XZA2s today on my coach, they have served me well and outride, and mpg the Bridgestones and Goodyears before them. I am more than halfway through the service life, so I could be disappointed in the future, however today, I would do it again.

[rodz]

Originally Posted by Sky_Boss

I don't believe fluctuations are "much less". I think that in real life they will be marginally different but not significant.

Based on what you just said, I suspect you agree with me that paying for nitrogen tire fillings is a waste of $$$.

I don't use nitrogen in my tires. Never have. Some here were concerned with pressure changes with tire temp. It will be a little less with nitrogen than it would be with air.

[JDL]

Originally Posted by rodz

I don't use nitrogen in my tires. Never have. Some here were concerned with pressure changes with tire temp. It will be a little less with nitrogen than it would be with air.

You are correct, as O2 molecules are denser than N2 molecules, so the pressure rise vs temp is more, not enough to warrant worry. Both gasses are close enough that the Ideal Gas Law works for both at the pressures and temps we are discussing. PV=nRT.


Concerning gas loss, the higher denser O2 (smaller molecules) will permeate the rubber faster than N2, however due to the partial pressures of air IE N2=78% of total air pressure vs O2=21% of total air pressure, the delta for each molecule vs molecular size, the gas loss differance will require a lab to quantify correctly.

That being said, if you fill your new tires to 100 PSI when new with air, there is 78% N2, 21% O2, 1% other. Over the next 2 years, you have added 5 psi quarterly, IE 7 times, if O2 permeates 3x faster as some people will claim, your 2 year old tires now contain ~ 92% N2. As the PPN2 rises, it will continue to be less "better than air" in gas loss through the rubber.

When I am breathing gas, I get completely OCD with % of gasses in my mix, with tires, I compress it, dry it, and dont worry about it. If I use the onboard air, its dry enough for my tires.

[Hit_the_Rhod]

I think a lot of the hype about using pure nitrogen for tires is a hold over from using nitrogen for Oleo struts (think landing gear shock absorbers) hydraulic accumulators, and tires on aircraft. People think "Oh, it's used in aircraft, it MUST be better!"

Well, so some extent that is true. However, the primary reason it is used in aircraft is that it is DRY (moisture removed) NOT that it is Nitrogen! Aircraft travel at altitude, and it gets colder as you go higher (the standard lapse rate is 2 degrees F for every 1000 feet you climb), so at 10,000 feet above ground level, it is typically 20 degrees F colder than the ground below you. If the air temp on the ground is 45 degrees than at altitude, you can expect 25 degrees, and any water in your struts will be frozen. When you descend to land the ice doesn't have time to melt and the compression on landing can cause scoring in the struts if there is ice present.

Soooo, if you are flying your coach at 10,000 feet above ground level, with the wheels, and struts NOT MOVING, and then making a rapid descent to land where all the wheels, and struts will now go from motionless to MOVING QUITE FAST than it will behoove you to use dry nitrogen.

Otherwise, just use air, dry air would be better, but air nonetheless!

[Gary737]

Flying from sea level to 41,000 ft in a jet the "pressure change" is significant. Nitrogen is the standard, unless you are OK with a tire exploding in your wheel well. In a motor home from sea level to 10,000 ft, or the descent the pressure changes are also obvious, but easily manageable. If the tire dealer inflated with nitrogen I would be more then happy to have it, and adjust with good old O2. But I'll be checking and adjusting anyway so it really doesn't matter.... Unless flying this motor home up to FL 410

[gimblerotor]

Originally Posted by Gary737

Flying from sea level to 41,000 ft in a jet the "pressure change" is significant. Nitrogen is the standard, unless you are OK with a tire exploding in your wheel well. In a motor home from sea level to 10,000 ft, or the descent the pressure changes are also obvious, but easily manageable. If the tire dealer inflated with nitrogen I would be more then happy to have it, and adjust with good old O2. But I'll be checking and adjusting anyway so it really doesn't matter.... Unless flying this motor home up to FL 410

Not sure the pressure change from sea level to FL 410 is all that significant. If you flew your Motorhome to outer space the pressure difference should be about 14.7 psi.
I don't have to worry about my oleos freezing up because I have spring steel landing gear legs.
Jake

[skypilot_1]

Originally Posted by Gary737

Flying from sea level to 41,000 ft in a jet the "pressure change" is significant. Nitrogen is the standard, unless you are OK with a tire exploding in your wheel well. In a motor home from sea level to 10,000 ft, or the descent the pressure changes are also obvious, but easily manageable. If the tire dealer inflated with nitrogen I would be more then happy to have it, and adjust with good old O2. But I'll be checking and adjusting anyway so it really doesn't matter.... Unless flying this motor home up to FL 410

You obviously have not been around jets much

[Gary737]

I dont care to get into a debate here, so I'll rewrite my response. Nitrogen provides better temperature and pressure stability whether it be at sea level or at altitude. Wheel corrosion and diffusion through the tire wall are reduced. Maintenance is reduced. All are factors.

I would use it in the motorhome tires if convenient, but for me it's not.

[Hit_the_Rhod]

Originally Posted by gimblerotor

Not sure the pressure change from sea level to FL 410 is all that significant. If you flew your Motorhome to outer space the pressure difference should be about 14.7 psi.
I don't have to worry about my oleos freezing up because I have spring steel landing gear legs.
Jake

Tail dragger?

[Tireman9]

I covered the effect on inflation of elevation change back in July 2011 on my blog. Even provided the actual math formula involved.

Many are making tire inflation too complex. It isn't Rocket Science.

[Darwin]

Update. After taking my damaged tire to the selling dealer I was told to contact Michelin which I did and was told to take it back to the selling dealer. While I was there they attempted to contact Michelin but were unable to make contact. I have sent two emails to Michelin requesting that they contact TCI about my tire. The emails have gone unanswered.

[RolandRock]

Originally Posted by Darwin

Update. After taking my damaged tire to the selling dealer I was told to contact Michelin which I did and was told to take it back to the selling dealer. While I was there they attempted to contact Michelin but were unable to make contact. I have sent two emails to Michelin requesting that they contact TCI about my tire. The emails have gone unanswered.

Apparently getting your defective Michelin tires replaced IS Rocket Science !

[Gordon Dewald]

Originally Posted by rodz

If you fill the tires with nitrogen the pressure won't fluctuate nearly as much.

Just finished watching parts of this. Some interesting information that keeps everything in perspective.

http://www.irv2.com/forums/f59/nitro...ml#post3375038

Just as a point of interest if you subscribe to the leaking tires. It should take about a year of topping up the tire to have the tire filled to about 98% nitrogen (based on only oxygen leaking and the nitrogen being retained).