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tire question/weight of 30ft. rigs
Yahoo Message Number: 141835
No one responded to my question on weights w/the 30fters. The reason I was asking is I was wondering if there is any correlation between over weight [and I'm fairly sure almost all 30/31fters ARE over weight], tire pressure and blow outs.

No matter how hard I try, I cannot get my rig UNDER the allowed weight. I'm either AT it, or, if tanks are full which happens sometimes as I travel, [I always try to have full water...it's the hardest thing to find in boonie areas], over by sometimes as much as a few hundred pounds.
 It has always been this way. In the beginning, when I was always over by several hundred pounds, I was running my duels at 75, front 65, and never had a blow out.
 On the advice of others after getting the rig weighed at the scales, and the manual w/air pressure recommendations, I raised the duels to 80lbs. and the front at 67. I greatly reduced my constant CC by 200/300 lbs.

Since then, with being MORE attentive to weight, much better at keeping air pressures constant, and being much closer to the allowed weight limit, I have had three duel blow outs...two on either side inside, and one outside driver's side.
 These were ALL newer tires..less than two years, and less than 10,000 miles.

I was asking if others w/30fters. had similar blow outs or tire failures. I know some of the smaller rigs w/the smaller engines have low CC as well. Do you find that your tires seem to fail more often?

I have an infra red heat scanner...after having Tireman valves installed, I had the shop fill the tires to 80/67 .When I stopped @ Truckee from Grass Valley to check on them the next morning, Air pressure was @77 to 74.5 in the duels, and 64.5 on the front.
 Not happy....went on to Reno, and checked them again...both duels @85 to 87, and fronts @67.5....infra red showed fronts running @115, rears, shady driver's side 125/129, pass. side 134/136.
 So, I'm wondering if having the tires get hot, and build up pressure, might be the reason the duels are blowing. I'm beginning to think I ought to START w/ 75/77 lbs. in the duels.

Any others have any input into this?

Gini Free and Junah, canine xtrodinaire "CHERRYOTTE" our litte red home on wheels "Growing old is mandatory. Growing wise is optional."

[Non-text portions of this message have been removed]
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Gini Free and Junah, canine xtrodinaire
"CHERRYOTTE" our little red home on wheels
"Growing old is mandatory. Growing wise is optional."
Re: tire question/weight of 30ft. rigs
Reply #1 –
Yahoo Message Number: 141837
With regard to the tires, use the pressure specified in your vehicle owner's manual, and do not exceed the pressure shown on the tire sidewalls.  Don't try to second guess the engineers who get the big bucks for figuring these things out.  Also, tire pressure should be set relative to sea level.

Read this:  http://www.tirerack.com/tires/tiretech/techpage.jsp?techid=167

Dick
Re: tire question/weight of 30ft. rigs
Reply #2 –
Yahoo Message Number: 141840
We have a 30IB AE.  No blow outs. Run right at or slightly over CCC.  75  for duels & 70 fronts.  56K on motor home.  All over USA lower 48 & many Canadian Provinces. Up Bear Tooth twice.

We also tow a toad.

Bob SE 5
Kathy and Bob on the Go
Re: tire question/weight of 30ft. rigs
Reply #3 –
Yahoo Message Number: 141841
Gini, we have been full timing in our 30' for about 5 years. On our second set of tires.
 We run 65 in front and 75 in rear. So far, no tire problems. We also are at or over just as you. First set of tires were the Michelin LTX and second is Uniroyal Laredo.

Jim C
Re: tire question/weight of 30ft. rigs
Reply #4 –
Yahoo Message Number: 141842
There is definitely a correlation between tire temp and failure. Sidewall flex from overloading loading can contribute to a tire overheating! My tires seem to run at 10 degrees above ambient outside temp. Even when overloaded, i check the temps with an infared gun at every fill up! So id say something else is going on based on the temps your reading! So I'm  not sure being overweight is the only reason. I run bfgoodrich tires, installed by Discount/America's tire. Previously I had matching Cooper Dominator tires that lasted 12 years (i know yikes!) which were Installed by the PO and replaced by me after I bought the LD.  So I doubt brand is the issue either. Maybe your tires are too wide and they are kissing under load, thats when the sidewalls touch between the dually pair, that can really mess up a pair tires. I would look for an installation or size/ratio issue. maybe your tires were not designed for your chassis.

Sent by wireless
Re: tire question/weight of 30ft. rigs
Reply #5 –
Yahoo Message Number: 141853
Gini,

We have a 30 IB AE too. I'll give you our experience.
 Our rig has had at least 3 sets of tires. 2 were Michelin MTXs. One set was replaced before we got the coach with the second set. That second set started to check the side walls badly within two years. One year indoors. One year outdoors with tire covers. Ran these 65/70 and shifted to 70/75 later.
 We lost one MTX to road damage. A sidewall tear deep and close to the wheel on an outside dualie. We never felt the impact. And we had driven on it for some time. How much I don't know. We discovered it in pre-flight checks before a trip, not during.
 That makes you wonder about blow out possibilities. There seems to be too many: over and under inflation, road hazards, weight, tire construction.
 In trying to deal with the lack of ROI with the Michelins, we went with the Tireman's ideal of the Goodyear G949RSA all steel tire. He had sung its laurels to heaven. Including road handling stability and non compromised construction in these ever-save-a-buck-for-profit corporate concerns.
 In order to get some satisfaction out of Michelin, we bought the Goodyears from Americas/Discount Tire which also deals with Michelin, where Tireman does not.
 Well... Tireman was right. We have gotten better wind load handling and the feel of the coach has improved. With the weight of the 30' we dont feel the Kabam of California rotten road syndrome near as much... I-10 near Redlands not withstanding.
 We run all six at roughly 75 to 80 PSI COLD.  (80 being the stamped sidewall figure). It varies from any gauge to gauge. Calibrated gauges are rare. I have too many and they all measure slightly differently.
 We have not weighed as of yet. But assume we are pretty much at or over the CC limit.
 Our tires do not kiss between dualies, they are steel sidewall which will help in that regard. Bias ply will be more apt to sag in this regard. The Michelins did. Although They did not kiss, ever that I know of.
 Temperature we have no data on. Since I'm up here in the crazy high desert area where air temperature hits 117 degrees F or more in summer, I can only imagine what the black pavement temperature is. (Shoes come off around here so you don't tend to dirty the carpets as much from melting dirt tracked on shoes in summer...really I have seen it...) Anyway, makes me tingle to think how much heat might be given to the rubber tire considering the pavement, the brakes, the friction force etc.
 If you are considering new tires at all and can afford the G949RSA, I can highly recommend them for a 30 foot coach.

As always, YMMV.

Lydia
Lydia.
Current: 2020 JLUR w 15’ Squaredrop
Former: 2006 30IB Anniversary Edition
Re: tire question/weight of 30ft. rigs
Reply #6 –
Yahoo Message Number: 141865
On reading the replies, and thinking about this...I *do* change altitudes and heat signatures often as I travel...it was 93 in Auburn when the valves were installed and somewhere around 700 ft. elevation: and it was 47 degrees and 5700 elevation in Truckee when I checked the air pressure the next am. I've gone from Northern CA. to Sturgis, S.D. in the last four days!
 Reno is what...sea level? That's where the pressure had significantly changed. And hotter as well. The higher tire temps were on the 'sunny side' of the rig, next to the exhaust.

Too many changing variables.

But even tho the manual states that the rears should be running @80psi., with the possible over-weight limits, it still seems that setting air pressure @75/77 at or around sea level has worked better for those of us with 30fters. As I stated, even in the beginning when I KNEW I was over  by several hundred lbs., I ran the tires @75/77.
 No blow outs. That was on BFGoodrich, which is what I have on the rig now--all the Michelins were replaced as the side walls cracked within months of install, or had blow outs.
 When I'm ready for new tires, in about another four years [if these make it that long], I will upgrade to the steel side walls. It's the weight of these longer rigs that makes it a wise choice. Wish they weren't so expensive tho!
Gini Free and Junah, canine xtrodinaire "CHERRYOTTE" our litte red home on wheels "Growing old is mandatory. Growing wise is optional."
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Gini Free and Junah, canine xtrodinaire
"CHERRYOTTE" our little red home on wheels
"Growing old is mandatory. Growing wise is optional."
Re: tire question/weight of 30ft. rigs
Reply #7 –
Yahoo Message Number: 141868
Quote
With regard to the tires, use the pressure specified in your vehicle owner's manual, and do not exceed the pressure shown on the tire sidewalls.  Don't try to second guess the engineers who get the big bucks for figuring these things out.  Also, tire pressure should be set relative to sea level.

Read this:  http://www.tirerack.com/tires/tiretech/techpage.jsp?techid=167 Dick
In addition to the link that Dick provided there are some others in the same TireRack page that are good reading.  This one also applies to the conversation.  I almost put in the ones about wet weather and dry weather handling but that may be overkill.  If your interested there are links to the other articles at the end of each article.
 http://www.tirerack.com/tires/tiretech/techpage.jsp?techid=147
Currently: 2008 36' Tiffin Open Road
Previously: 2007 Mid Bath
Re: tire question/weight of 30ft. rigs (long)
Reply #11 –
Yahoo Message Number: 141889
Quote
No one responded to my question on weights w/the 30fters. The >reason I was asking is I was wondering if there is any correlation >between  over weight [and I'm fairly sure almost all 30/31fters ARE >over  weight], tire pressure and blow outs.

No matter how hard I try, I cannot get my rig UNDER the allowed weight. I'm either AT it, or, if tanks are full which happens sometimes as I travel, [I always try to have full water...it's the hardest thing to find in boonie areas], over by sometimes as much >as a few hundred pounds.
On the advice of others after getting the rig weighed at the scales,  and the manual w/air pressure recommendations, I raised the >duels to  80lbs. and the front at 67. I greatly reduced my constant >CC by 200/300 lbs.

Since then, with being MORE attentive to weight, much better at keeping air pressures constant, and being much closer to the >allowed weight limit, I have had three duel blow outs...two on >either side  inside, and one outside driver's side.

These were ALL newer tires..less than two years, So, I'm wondering if having the tires get hot, and build up >pressure,  might be the reason the duels are blowing. I'm beginning >to think I  ought to START w/ 75/77 lbs. in the duels.

Any others have any input into this?
Hi Gini,
 I have a 26.5 MB so I don't deal with the weight issues you've brought up. But I have some thoughts about your post.
 I wanted to first address the weight issue. I think it was 2008 model year that Ford raised the GVWR of the E450 chassis to 14500 lbs. from 14050 lbs. and they were still using the same tires. You didn't mention the model year of your LD; IF it is an older E450 chassis, being a couple hundred pounds overweight, while not a good thing for the truck chassis, should *not* be an issue for the tires IF you are inflating to proper pressures. On the other hand, if you do have a newer rig that has the 14500 lb. GVWR, being overweight might be a factor.
 From some of the responses, it seems that blow outs are not something that most owners of 30/31' LD owners are experiencing.
 You never mentioned the cause of your blow outs; were they sidewall cuts? Punctures? Sidewall failures? Did anyone ever give you a reason for those blowouts?

Here are a few things I would look at more closely.
 Do the rear tires wear evenly? Uneven tire wear could be a sign that the rear axle is out of proper alignment (bent or otherwise damaged) or that one side of the rig is overweight compared to the other side.
 How do you level your rig? If you use leveling blocks/wood, do you always support both of the dual tires? (I've seen folks in campgrounds that don't have enough leveling blocks and they just raise one tire on planks putting a lot of stress on that one tire. Granted that the tires aren't turning but that one tire is getting very stressed sidewalls. Yes, I've even seen Lazy Daze owners do it that way too!)
 Do you drive on poor quality roads with lots of pot holes that can cut the tires? Do you hit curbs on turns?
 In no way am I trying to insinuate that you are doing any of the above; just pointing out that there could be reasons other than weight, temperature, and tire pressure for tire failures.
 If I were you, I would get the rig weighed on all 4 corners to see if one corner is seriously overweight. (that would also show up in uneven tire wear) If there is a problem with balance to the weight, you will need to take corrective action.
 As for tire pressures, on my 26.5 MB, I wouldn't consider inflating the rear tires to anything less than 75#. I run 65# on the fronts and 78 in the rear; pressures based on 1000' above sea level and 70 degrees. I do NOT change the pressure when I am in the mountains.
 One other thing I want to mention is tire diameter. From what I've read, it is important to have all of the rear tires be close to the same diameter. In other words, if you have three tires that have similar wear and you install a new tire on the rear axle, that new tire is going to have a larger diameter and will probably be subjected to more stress. That is why all the rear tires are supposed to be inflated to the same tire pressure too.

I hope your luck improves, Steve K.
Steve K

2003 Mid-bath
Re: tire question/weight of 30ft. rigs (long)
Reply #12 –
Yahoo Message Number: 141901
"I wouldn't consider inflating the rear tires to anything less than 75#. I run 65# on the fronts and 78 in the rear; pressures based on 1000' above sea level and 70 degrees. I do NOT change the pressure when I am in the mountains."

A few points on tire pressure, particularly to 30' and 31' owners.
As previously mentioned, weighting the rig is crucial. If an imbalance, in the rear loading, is noticed, correct as much as  possible.
Next re-weight it and use the highest weight side's weight when consulting the manufacturer's tire pressure chart. Find it's proper pressure and use it on all four rear wheels.
As Steve mentioned, changing rear wheel in pairs is important for maintaining the same tire diameter, thus the same loading per tire.
 Check and correct the tire pressure only when cold. Like Steve, I never lower the pressure at high altitudes, they will run a little higher.
The tire pressure can run much higher than the recommended pressure when the road and air temps are hot.
NEVER reduce the tire pressure when hot and never run less than the recommended pressure. The tire engineers know all about how roads, speed and weather conditions can effect the tire's pressure and they have built in the needed strength to handle it. Don't try to out think them. Don't let anyone, including tire shop employee, tell you differently.
There are a lot of myths concerning tires.
Pressure is a good thing, it supports the tire and keeps it from overheating by reducing the sidewall flex. The lower the pressure, the more flex equaling more heat.
The tire manufacturer's pressure charts take the actual weight into consideration and provides the calculated best pressure. Use it.
The previously mentioned RV tire information sites, such as Michelin's, are excellent sources of information and advice given should be considered as gospel.
 If the total rear axle weight is at or over the GVW or total amount the four duals can safely carry, which is [possible with the 2008+ models), get the weight down. That is the only safe choice.
If it is impossible to keep your rig's weight at or below the GVW, it's time to move on to another model or brand that can handle your required load. To continuously run overweight is irresponsible.
You are endangering yourself and the general public.
It has been said here many time before, 30' LDs are not the best models to full-time in. For most, they just don't have the needed CCC.

Larry
2001 MB
* Not to be confused with Larry W (3000 of my posts are actually from expert Larry W due to Yahoo transition mis-step)
 
Re: tire question/weight of 30ft. rigs (long)
Reply #13 –
Yahoo Message Number: 141907
Thanks for your thoughtful reply.

My rig is a '98, so it's the lower of the two CC's.

All my original tires were purchased at the same time. As the blow outs occurred, the other tires were assessed for wear...they were all "like new" with no visual wearing, even or otherwise. Pronounced excellent condition by the shops.

Because the first set had serious cracking within a few months ALL were replaced pretty much within that same year. The first blowout was inside pass. side, by the exhaust. The tread totally separated from the tire, and there was a burst 'bubble' under the tread.

When getting that one replaced, I had them replace the two front tires, as the sidewalls were showing cracking...three out of the six new.

They said I had hit something hard enough on that inside duel to cause the steel belts to separate til it blew.. I doubt that, as, trust me, I would have known if I hit something that hard in a 30fter.

The second was outside driver's duel. The tread came off, but there was still air in the tire!  That left two originals, and four new.
 Before taking off this past May after staying housebound for about a year, I had BOTH outside duels replaced due to more cracking. That means all six had less than 5,000 miles, and were mostly less than a year old.

The third blow out was...very weird....it was the inside pass. side duel, and I felt it starting to go. The sidewall facing right totally shredded--looked like someone had taken a razor to it. Tire man said more common than you'd think.

What is really ironic, is I had ALL the tires checked just the day before @Discount in Flagstaff, AZ.. The outside duel/drivers and the inside duel/pass. had very slow leakage. They pulled them and re-set the long valve stems. All tires were checked for wear [none], and air pressure set @ 80 rear, fronts 65. That tire blew not 300 miles later.
 All the tire people I talk to  [Les Shwab, Discount, American, etc.] all say that the Michellan made Commercial BF Goodrich tires are medium grade, and that Michellans' sidewalls are too soft for a rig that is this close or over weight.

I have always weighed my rig front and back, but haven't found anywhere to weigh each corner yet. The rig is always under in the front by 100/140 lbs., and over 100/300 lbs in the rear.
 Considering where they put the black water, grey water, gas tank and fresh water tanks [ALL in the rear]..it's really really hard not to be over.

As for balancing, I try. There is just so much storage 'up front' that can take some of the load off the rear duels. It's the nature of the 30fters. As it is, most of my cabinets are partially empty, and I have the problem of things sliding and moving around--there's too much room!

That was why I was asking what others who have this model do...and all the replies I got privately say that they ALL run over by several hundred lbs.
 Oh, and I have Kwikee levelers...I rarely have to use any additional blocks, and most always have to use them in the front when I do. I carry the stacking yellow ones from Camping World. I don't do much "off road" type surfaces, but some of the roads in Ca. are rough. I drive SLOW...55 to 59...easy does it...:-) After some 39,000 miles, I'm a pretty good RV driver. {I also used to be an operating engineer--heavy equipment, as well as an oiler for years].

I just can't help but feel that my troubles with blow outs STARTED when I started putting 80psi. And what with the traveling I do, checking air each am isn't a good indicator, since it may be hotter, colder, higher, lower...sunny side, shady side.

All I can do is all I can do I guess.
Gini Free and Junah, canine xtrodinaire "CHERRYOTTE" our litte red home on wheels "Growing old is mandatory. Growing wise is optional."
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Gini Free and Junah, canine xtrodinaire
"CHERRYOTTE" our little red home on wheels
"Growing old is mandatory. Growing wise is optional."