tireman9

Depending on the size of your tires i.e. 16" for Class-C like mine or 19.5 or 22.5 as on most Class-A you will probably be within the nominal tolerance when you add the TPM Sensor. My non flow thru sensors from TireTrakker weigh 0.45 oz so this would be less than a 1/3 oz weigh at the rim flange location where weights are placed. Flow through sensors are a bit heavier (don't have exact numbers but I think about 0.75 oz). Here is a blog post on tire balance. The vehicle sensitivity chart is especially informative and shows that simply "balancing" the tire & wheel may not solve a ride problem. Remember we can "balance" a cinder block but I think you will agree that it would not ride well.

Quick answer to this question is I bring this up for a couple of reasons. One is that I just read a RV forum post from someone that was stuck in mud and tried "spinning" their tires to get out. (it didn't work) The other reason is that with Canada and portions of the US that normally never get real cold in a deep freeze, there will be some vehicle owners experiencing frozen ground conditions and they may never have had that experience before. The reason the practice of spinning your tires is dangerous is that very few RVs have limited slip differentials so when they rev the engine and spin their tires in a effort to get going they may UN-wittingly be spinning their tires at speeds high enough to cause a tire failure and explosion. When you spin your tires the spinning tire is going TWICE the speed indicated on your speedometer. This picture shows what can happen to a passenger size tire. As you can see in this failure, not just the tread comes off and the sidewalls blow-out but the Hi-Tensile bead wire fractures in multiple locations which allows the complete tire to become a missile. When this happens with a small passenger car tire it may only "remove" one corner of the car. Sometimes a "free spin" tire failure ends up almost a mile away! Now for a moment think what a LT or TBR tire might do if it were to fail in a similar manner. If you are stuck, the best way to get out is to either use sand or gravel or to get some towing assistance. But please never simply spin your tires. The above post will be published on my blog next week but I thought this safety warning was time critical so FMCA gets an early look.

I see no meaningful advantage to switching from duals to singles. I do see many downsides. BUT if you like the looks and the cost isn't a consideration I have no technical problem with people modifying their RV with this change as long as the load capacity of the vehicle are covered. Have you considered getting your wheels gold plated? Sure would be distinctive. Just be sure you understand all the consequences.

What did the dealer say when this mistake was pointed out? An argument could be made that the dealer should be held responsible for not providing the proper tires or at least for not providing a new tire placard for this "dealer installed option".

The vertical mount with the water connection on the bottom is what I intend to go with. This will make emptying for winterizing easier. This project is taking a back seat to my repair & redesign of the holding tank dump valves. Coachmen didn't properly orient the slide valves so two have been damaged from road debris. Have the new parts and was about 85% done with removal of old connections when Winter set in here in Ohio so it will be March before I can finish that wonderful job. After that I will re-visit the water surge tank.

Drive tires do wear because they are "pushing" all the time. If you have a TAG axle then the tires are also being dragged or pushed around each turn or corner. Here are the details. If you think about it, a car has all 4 tires rotating around a centerline that is "pointing" to the center of the turn radius. Many years ago car manufacturers discovered how to design front suspension geometry to include something called "Ackerman". Here is definition that explaines what it is. Ackerman addresses the front end and solid axle rear ends basically have the centerline of the axle pointing at the center of the turning circle If you add a 2nd rear axle or "TAG" and project the centerline of that axle, clearly it can't be pointing to the same center of the turn as the drive axle is. This is one of the reasons multi axle RV trailers have such short tire lives. Now large 22.5 TBR tires don't flex like smaller 15" or 16" trailer tires so the large tires are forced to slip (wear) If you want to learn more about Ackerman there are some videos on YouTube. or here

Haven't used this protectant but you might check it out. Also found THIS review and more info on a car performance forum

Bright-White is a harsh cleaner. It appears to partially dissolve the surface rubber. To see for yourself spray it on a scrap White Sidewall and watch the white flow off. This is rubber being removed from the tire sidewall. I understand the desire to have your tires "look" a certain way but I stick by the soft cloth and soft soap recommendation for minimal damage to your tires.

Hi all. Hope you all had Happy Holidays. Sorry but I do not have any specific data on different versions of 303 so can't answer the question of "Aerospace" vs "Marine". It may just be marketing and packaging difference. RE the use of any protectant: 1. NEVER use anything that contains Petroleum Distillate as those chemicals can attack the rubber molecular structure 2. I have seen tires damaged from excessive use of products advertised as "tire protectants" 3. No spray on chemical can do as good a job as a White tire cover can when it comes to keeping the tire cooler when in direct sunlight. Remember HEAT is a #1 killer of tires. Quickly through the melting of tire components or slowly through degradation of the molecular bonds. I use white tire covers to protect my tires from heat from the Sun. I have occasionally used spray on but no wipe-on preparations. If you have to wipe something on, you are probably also removing some of the tire's chemicals that are there to protect your tires in the first place. I have found that "No-Touch" brand seems to work well and since it does wash off after a couple of weeks if there is heavy rain I know it is not a petroleum product. When cleaning your tires the best guidance I can provide is to use the same car wash soap and soft cloth you would use on your expensive paint job. High pressure equipment can damage tires and stiff bristle brushes can leave microscopic scratches which can accelerate the attack of Ozone. Hope this helps.

Rich & Lois and others, Yes it is true that a good portion of the "rubber" in tires is really synthetic which means the raw material is petroleum based. Today's passenger tires have very little if any natural rubber but as you move up in size there is an increasing % of natural rubber. Some 22.5 size tires have Natural rubber as a component but without access to the secret formulas I can't address the % which could range from 0% to maybe as much as 25% or more . There is also the special high strength brass plates steel to consider along with numerous other materials such as titanium oxide, From Whikipedia we see Natural rubber, or polyisoprene is the basic elastomer used in tire making Styrene-butadiene co-polymer (SBR) is a synthetic rubber which is often substituted in part for natural rubber based on the comparative raw materials cost Polybutadiene is used in combination with other rubbers because of its low heat-buildup properties Halobutyl rubber is used for the tubeless inner liner compounds, because of its low air permeability. The halogen atoms provide a bond with the carcass compounds which are mainly natural rubber. Bromobutyl is superior to chlorobutyl, but is more expensive Carbon Black, forms a high percentage of the rubber compound. This gives reinforcement and abrasion resistance Silica, used together with carbon black in high performance tires, as a low heat build up reinforcement Sulphur crosslinks the rubber molecules in the vulcanization process Vulcanizing Accelerators are complex organic compounds that speed up the vulcanization Activators assist the vulcanization. The main one is zinc oxide Antioxidants and antiozonants prevent sidewall cracking due to the action of sunlight and ozone Textile fabric reinforces the carcass of the tire Here is a good article on the topic. What hasn't been addressed is the research, manufacturing and transportation costs. With the ever increasing pressure for improved fuel economy, smooth and quite ride as well as, long wear and all season performance the R&D efforts are continually increasing. I think it is important to remember that oil price at the pump is a poor reflection of the real cost of the commodity especially when most of the materials are bought based of future delivery so current day to day variations have little affect of the price of oil someone is willing to commit to 5 months or a year in the future. One thing to look as is the profit margin of the tire companies over a multi-year basis. For example I believe Goodyear profit in 2013 was about 3% of sales income. If you want the nitti gritty check this web site and you will see the Return on Assets ranges from negative 6% tp plus 5% Now please remember I may be a tire engineer and I even play one at FMCA Conventions but I am not a financial advisor and as we all know past performance is no guarantee of future performance.

"I will check pressure this week" From that comment are we to assume you 1. Didn't confirm the proper pressure when the tires were first installed? and 2. You do not have a TPMS You should do #1 ASAP and if you don't have a TPMS, get one soon as it would be awful to turn a new tire into scrap due to an unidentified nail puncture or valve leak.

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Tanks are empty & flushed. so no surprises for me. Gary Bunzer said "you’ll see that clamp (and sealant) whenever the holding tank is made out of HDPE; high-density polyethylene. You cannot cement, bond or weld dissimilar thermoplastics. The outlet of a PE tank is tapered a little and some factories could not understand that the tighter you tightened the clamp, the more it tried to squeeze the ABS pipe out of the hole. It was necessary to cut the ABS outlet pipe to just the right length so that it wouldn’t slip out and yet would not protrude too far into the outlet, trapping debris under the outer circumference of the pipe. It wasn’t necessarily a great design but when coupled in tandem to the other tank outlet via the whole termination assembly, it sufficed. Today you’ll mostly see spun-on or welded fittings to make the connection. " I do see what appears to be a separate piece of pipe inside the neck of the tank. Apparently the tank is not ABS, (else why the clamp and inner pipe?) even though Coachmen tried to solvent glue an ABS pipe union onto the neck of the tank. They did not try and attach the inner tube to the ABS pipe or fittings. That may be why they also applied some type of sealant on the outside of the tank neck to pipe union joint. Really abysmal design, engineering and workmanship in my opinion.

As cold weather hits Ohio the job of re-plumbing the dump valves and fixing the screw-ups in the lines as installed by Coachmen is going slower than hoped. But I am making progress. Have new replacement valves, new ABS pipe and appropriate rubber hose connectors. Am removing the old solvent joint on the black tank which is a slow job but Coachmen knew they would not have to cover the cost of repair under warranty so I understand why they did the half-a$$ job. They probably saved at least $1.50. Oh well that's the real quality seen from our RV assemblers. I note in Nov FMCA mag on pg 22 "House Calls" a picture that looks similar to my tank exits. I see the hose clamp around the ABS pipe. What purpose does a hose clamp serve on solid ABS pipe?

My dump lines were improperly installed by Coachmen when they assembled the RV. They decided to angle the shut-off valves down which makes the effort to open or close the valves higher than necessary. This placement also has resulted in the valve from the black tank being broken by road debris being thrown at the plastic valve by the rear tires. Since I have to now do my second valve replacement, I want to try and re-locate the valve in a more horizontal position to make actuating easier and also to move the valve up away from the trajectory of road debris. What I need to know and confirm before I complete the disassembley is what the hose clamps are clamping? Is there a piece of large rubber hose that I can replace with new and relocate the hard ABS lines? The area near the clamp feels hard as if it is actually plastic and not rubber. If it was a piece of hose I would think it would need to be clamped around the tank exit and another clamp around the ABS pipe but there is only one clamp. This shows the bad location of dump valves You can see the mud flap I added in an attempt to protect the valve but it wasn't enough. You can see the broken handle but not the cracked valve body. Here is the Black Tank Clamp. I have started the valve removal Here is Gray tank clamp

General comment: Have to wonder why the RV industry seems incapable of developing and using a reliable level sensor for holding tanks. Maybe they are just not interested in building a "quality" product. Running a hose into my RV every few days to pressure wash the black tank was never pointed out as normal task when the dealer wanted me to buy a new RV. Maybe if I ever buy a new RV I will simply take the unit back after every camping trip and ask for warranty service.

If you run a +10% on inflation over the minimum needed to carry the load you will have a few advantages. 1. You will not have to chase the +/- couple of psi you can expect to see due to changes in Ambient temperature. 2. If you monitor your inflation with a TPMS and see a slow drop of say 1% or 2% a month (which is NOT abnormal) you will have advance warning of the need for a few psi. If you need to add say 3 psi you can do this when the tires are warm if you do the following. A. Measure the tires when cold. B Record the number of psi needed for each tire. Will probably be slightly different for each tire. C When you get to a truck stop that has air, simply measure the hot pressure and add the number of psi needed in "B" above plus 1 or 2 psi. D Next morning when the tires are again cool you check with your hand gauge and you should find you are at the cold inflation you need or maybe + 1 or 2 psi which you can easily let out. This approach avoids the need for carrying a compressor around. I think you will be better served by having accurate digital pressure gauge and TPMS than a compressor.

Definately go with "Steer" or "All Position" tires. If you go with "Drive" tires on the rears it will mean you can not rotate the rears to the front or to place the two fronts on one side of the rear if there is a need at some point in the future to move the tires around.

My first thought is Alignment with Camber being the most likely culprit. Toe is more likely to cause uneven wear of both front tires but just getting the alignment checked and set to spec will cover both. One thing to ask fo is a printout of both the Before & After measurements.

Here is a post with the math. Simple answer is 2% pressure for each 10F

Tom, For me one of the biggest problems is the improper use of the word "Blowout". This really is a hold over from our parents day of tube type tires. Tubeless tires can have a suddden loss of air but in my experience this is always preceeded by one of two things happening. 1. A slow leak of air which turns into a "Run Low Flex" failure. Here is a report I did on one such failure. TPM will provide warning in this case. 2. Impact sidewall cut or less frequently and harder to cause, a large cut to the tread area. Here is a report of a "Blowout" that hadn't happened yet that happened on my personal car. Obviously the tire had not lost any air so the TPM will not provide any warning but with a few more miles the sidewall rubber would let go and in just a few revolutions once the crack grew and the tire would have lost all its air almost instantaniously. This would also be a "blowout" to the average user.

I run both internal and external sensors. Ya I'm strange and have a tire fetish :-) I run both so I can answer questions about TPM numbers. Each has advantage & disadvantage. Major dis-advantage of internal is cost of replacing batteries as you have to dismount and re-mount the tire. Also I am not aware of an internal sensor with user replaceable battery so you have to pay $$ for a new sensor. BUT internal provide more accurate temperature numbers. Advantage of external is user replaceable low cost batteries. Disadvantage is less accurate temperature numbers BUT I have found no meaningful difference in the pressure numbers between the two types of system. I am primarily concerned with pressure. Temperature is a minor interesting feature.

If they were all 36 psi @ 100F I am not surprised that 4 months later at cooler? temp they measures 30. In general tires loose 1% to 3% air each month when temperature compensated in a stationary test in a lab. What was the temp when you measured Oct 1?

Glad you were able to make it to Redmond. Good question with relatively simple naswer. First let me relate my experience. After leaving Redmond I spent a number of weeks in OR, WA, BC AB, Glacier Nat Park & Yellowstone and had a number of days when it was warm followed by snow or frost the next AM. As I mentioned in my Seminar I have two TPM systems on my coach (internal and external) so I can compare the readings for both pressure and temperature. Yes temperature will affect the tire pressure. I have a few posts on Temperature and pressure, including one with all the technical formulas for those so inclined. The rule of thumb is about 2 percent change for every 10°F change. An example would be if you set your cold pressure to 80 psi in Oklahoma City in November and it's 45°F you may see your cold pressure has increased to about 86 psi in Phoenix the next morning when it is 85°F. BUT Operating temperature is really a function of the heat generated by the tire flexing. The upper limit of tire temperature when properly inflated and loaded, is reached when the heat (BTU) flowing out of a tire is equal to the heat being generated by driving. The flow of heat out is faster when the outside air is colder then when it is hotter so there are some complex interactions. I'm not going to put everyone to sleep with the details on heat flow. BOTTOM LINE: When you set the pressure in the morning the tire will partially adjust for the change in outside temperature as outlined in your example so you should not make change when the tire is hot or until the tire has had at least a couple hours to reach ambient temperature. I know this based on my direct observations made during my travels in Aug & Sept. You should still be withing +/- a couple psi of your goal "cold" pressure each morning of a travel day. Remember you establish your goal pressure bu knowing your actual tire loads (corner loads), using your tire mfg Load/Infl tables to learn the MINIMUM cold pressure and then add 10% to the Min. Inflation to get your goal pressure.

I got this question and thought that others might be wondering about the same topic. Jim K asked Subject: tire pressure Message: I will be traveling in the desert for the first time and I am wondering if I should reduce the tire pressure before I go. The hot road will increase the pressure and I am afraid of damaging my tires. ++++++++++++++++++++++ Hi Jim, No you don't have to worry about hot roads. IF you run the correct cold pressure Also you should NOT reduce the cold pressure to "compensate" for the hot roads. Now you didn't say if you have a standard RV trailer or a Motorhome so I will give you the short answer for each application. (FMCA members can share this part with friends with towables) Trailers: You should set the Cold Inflation to the pressure on the tire sidewall. If you look at the sticker on the side of your trailer you should find the tire size, type, Load Range and pressure recommendation from the manufacturer. In almost all cases the recommended inflation is the inflation on the sidewall of the tires. Have you confirmed you are not overloading any of your tires? Simply guessing or looking at the tires is not good enough you need to get the trailer on a scale and at a minimum get the total load on the tires. Now you can't assume the load is equally distributed side to side or axle to axle Measurements of thousands of trailers suggests you need to assume at least 53/47 to 55/45 split axle to axle and split side to side so you need to calculate the heaviest load based on an estimate of 27% to 30% of the total being on one of the 4 tires. A better method is to get individual tire loading. You can learn more HERE. Motorhomes are a bit different than towables. Here you need to get the "corner" loading as the side to side difference is affected by the placement of things like generator, water tanks, refrigerators etc. The Front/ Rear loading is obviously different and for most motorhomes the number of tires on each axle is also different. You can use the information on your placard but a better method is to get the actual tire loading and then using Load/Inflation charts establish the MINIMUM cold inflation then add 10% to get your Cold Set inflation. THIS post has some info and a link in it. Bottom Line When tires are designed, we tire engineers know that some vehicles will be driven on hot roads. Tires will normally run +20°F to +50° above ambient. You should run a TPMS to get warning of air leak due to puncture. If you are driving in the USA you should have no problems. If you are traveling to Saudi Arabia, the Sahara or Australian outback then we need to take some additional steps and precautions. I think that if you look at some of the dozens of posts on Load, Inflation and Temperature on my blog you will find more details and expamded answers to your questions.