tireman9

I am having problems changing my Profile. Right now the "Travel" item requires the selection of "with children" or "with pets" or "Full time". We do not travel with children or pets nor do we travel full time.

Coach did not come with an inverter. Only a standard converter. I am in a small Class-C so don't have the bells & whistles all you big class-a folks have.

Agree but didn't find any fully automatic system. Also didn't find DPDT switch but figure it should be OK as long as I disconnect the 110v system when the chassis engine is off.

No ice maker. I understand that it is possible to run on propane. Issue I have is that if there were an accident having the propane "on" can be a big problem. (See Mac the Fire Guy) Now some / many might not feel this is a serious concern and I understand accept that position. I may even be irrational in this concern but feel it is possible to keep the food cold enough to keep the DW happy using the 12 v system from my engine. Coach has no on-board inverter from Coachmen.

I understand the goal of having only one power source at a time. In My Class-C I only have 110V in the coach when plugged into shore power. Not sure if I understand the "backfeed" or "closed-Loop" unless I were to keep engine running (inverter active) and also plug in the shore power. I am installing a double poll switch that will isolate the inverter from the 110v system. Switch is accessible near control panel right inside my entry door. Ross and others, I will be at Indy. I should be in Governing Board / Committee 30 amp lot unless I burn to the ground on my drive from Akron to Indy Aim to arrive on 10th late afternoon. Can give "free tours" of my rv on 11th

Still have absorption fridge. I'm in a Class-C. The OE fridge works fine. I would just like to shut off the propane when driving.

I would like to not have to plug & unplug the refrig every time I connect to shore power. That plug is only acessable through the outside refrig vent door.

Got DPST so end up with on/off of the output of the Inverter. This accomplishes same as just completely removing the extension cord between output of inverter and the outlet that connects to the Refrig.

Brett Can do. Didn't think about the 110V side as I had no problems with prior install but I would prefer to do things in a safer manner. Off to Lowes electric dept.

Brett, Is the problem having 110V from shore power connected to the output side of the inverter? Is this a problem even with the inverter isolated from 12V? If I isolate the Inverted form O2 by either unplugging the "extension" or installing a relay switch you are saying it would be OK?

In my previous coach I installed a 750W inverter to power the 110v side of my absorption RV refrigerator. I power the inverter through a relay that only draws 12V DC from coach battery to the inverter when my engine alternator is running so I'm not going to kill the battery. This system worked fine. Kept food cold for a trip from Ohio to Oregon and back while driving about 6 hrs a day, Installing similar in current Class-C and have a connection I am pretty confident in but wanted another person to look at. In the attached simple schematic O1 is the outlet the fridge is plugged into and is located in the fridge "closet". O2 is an outlet in the space where a outside TV would be installed but I don't have a TV so the outlet is not used. I am installing the inverter in this empty space. According to schematic from Coachmen both these outlets O1 & O2 are on on same 110v circuit which is hot when shore power is connected to the coach. The 110v heating element in the Dometic fridge is rated 350 watts The inverter 12V + is connected to the continuous duty relay which connects through a 30A fuse to the coach battery, The relay is activated only when the ign switch is on. My question is.. If I make a male to male extension cord and connect the inverter to the O2 outlet will it work? Getting to the back of the outlets makes a lot more work, The extension cord seems too simple but I figure that as long as I wire the extension cord correctly to the 3 prong plugs it should work. Not to "code" but I think it is electrically safe. Comments?

Rayin. I already answered your post on adjusting tire inflation in the TIRES forum. The information will not change simply by asking the same question in this thread. For those that want the answer, here is direct quote from Goodyear " Since RVs can be loaded with many different configurations, the load on each tire will vary. For this reason, actual air pressure required should be determined based on the load on each individual tire. Inflation pressure should be adjusted to handle the tire carrying the heaviest load, and all tires on the axle should be adjusted to this standard. " I think the key part of the GY advice is the warning you are referring to is that you should inflate to the pressure needed to support the load conditions. The section you pulled that statement from was warning for people that simply lower pressure in an effort to get a better ride. I suggest you re-read ALL the information on the reference GY page. As I also pointed out in the TIRES thread similar information on how to weigh an RV and adjust tire inflation based on scale numbers is also provided by Michelin and Bridgestone. FYI true "blowouts" occur when a tire looses most of its air not when it is a few psi low. Being a few psi low can lead to belt separation after many thousands of miles operation. The federal tire placard numbers are as you know based on the GAWR not the actual loads. If you have loaded your RV to the GAWR then yes you must run the stated inflation

If you check the DOT serial you can see who made Dynatrac HERE

Rayin, I would be comfortable with suggesting lower than placard inflation IF I am talking with an RV owner that is making an effort to properly care for their tires. Info on placards is based on an assumption that the vehicle owner is not aware or interested in getting a better balance of performance and durability. Those inflations are assuming two things. First that the RV owner will not ever get on a scale and Second will never overload either axle of the RV. The problem is that RVSEF, who does 4 corner weights and provides inflation info at FMCA events, that has the data that shows that over half of the RVs on the road probably have at least one tire or axle in overload so the Second assumption about placard numbers is not supported by reality. RE tire company suggestions. While there are probably documents suggesting to inflate to placard pressure, I think Brett is correct in the idea that such info is written by the lawyers to protect the RV company when the owner fails to do proper maintenance of the RV tires. Lets look at what a couple tire companies offer for advice and information. Goodyear has an RV specific web site with information on how to weigh an RV and adjust tire pressure Michelin provides similar information Even Bridgestone tire Co that does not actively market to the RV community offers info on how to weigh and then set inflation Now there may be some small importer that has no engineering staff that wants to avoid having to answer technical questions that decided it is easiest to tell people to just follow the placard. This is not wrong but just no optimal advice. Then there are couple actual tire engineers, like myself, who monitor RV forums and attempt to provide even more detailed info to the small percentage of owners that want the details. But as I said to my knowledge there are only two of us on line and I may be the only one monitoring FMCA forum.

"New" age can be a problem or not. This isn't an easy answer as some new tires are stored in "better' conditions than others. Ideal storage would be indoors in relatively cool location. I have seen some tires at local gas station on mobile racks that are wheeled outside into the sun. Certainly not "better". Another thing to consider is when the warranty clock starts ticking. Some companies start the clock when tires are applied. In those cases you need to be sure the full DOT is recorded on sales receipt and that you keep the receipt and warranty info with other important documents. If your "new" tires are from a company with this policy you should have no problem. Other companies use the DOT date. In that case I would prefer 6 months or newer if possible. You might try and negotiate a discount of a few $ on the older tire Another thing to consider is how long you plan on keeping the tires and how you care for your tires. If you always cover them with a white cover whenever parked more than a couple days then you are following a good practice.

In my blog I showed the small air dryer I made out of parts from local auto parts store.

Ride is pretty subjective. While I have never personally done a comparison on 22.5" tires I have done many scientific comparisons on Passenger and Light Truck sizes. By scientific I mean back to back within the hour evaluation on the same roadway of new tire from tire company A vs new tire from tire company . We would run with no radio, A/C off and windows closed to cut down on distracting noise to do the comparison on the exact vehicle the tires were to be used on. This meant that many times we were using prototype vehicles when designing tires for new vehicles. We would NEVER use a Ford car to evaluate tires for Chevy or vs-a-versa as different vehicle manufacturers had different approaches to suspension, chassis and seat design. I specifically even remember when I had a special opportunity to do a "ride-along" when a set of wheels was being evaluated. In this case we ran the test route on one set of tires & wheels (cast aluminum) then the car came in and the wheels were changed with the tires being swapped out onto the 2nd set of wheels (also cast aluminum) in the same position so any difference in specific tires would not influence the results. I was amazed that I could feel the difference after less than a mile. All this is to point out that a difference in tires that one person may feel is not always a good predictor of what someone else may feel. This is especially true when comparing new tires with old worn tires. It is known that just a difference in tread depth can have a significant affect on ride with deeper tread being better. It entirely possible that the difference some feel is just due to tread depth along with the potential for personal expectations of what one brand can deliver vs another brand which can mislead or add to the difference between new vs 7 year old tires.

Here is an outside view on "Rallys" I read recently.

RE no seminars. My 4 Genealogy seminars are of general interest. The demographics of those that own RV ( MH or Towable) are similar. In my 2 seminars on tires I will add a slide at Indy and at Syracuse for the special inflation info unique to trailer owners. Not sure what else I can do to make more folks welcome.

x2 to comments from Brett, Bill and Carl.

What does the written warranty say? Some companies start the clock on date of application. Some on DOT. Having the dated receipt and written warranty down the road could be worth $hundreds so those are definitely valuable documents. You should be sure the clock on your "new" tires didn't start till the date they were applied.

When I was in OR before FMCA convention in Redmond I used one of the state scales after hours. The one I found had a wide open space around the platform. While things were not perfectly level it was reasonably flat and if the numbers had much different than my prior readings I could have run in both directions and with some math done an average. There was no rush as I was on a state road with not too much traffic.

Yes older is more likely but the reality is that if a specific date is given and a tire fails before that date the tire company gets sued. Also if a tire runs past that data then the tire company will be accused of cutting the time in an effort to sell more tires. The general guideline is to not run any tire that is older than 10 years old. There are some applications such as on multi-axle trailers 3 to 5 years is the normal max. Which of you has ever had a jug of milk go bad before the "expiration date? Who has had the milk still good days after that date. The issue is that we are dealing with organic material which can have numerous variables. RE DOT date. If you are still having problems get with me in Indy in July or Syracuse in Aug. Side note everyone should learn the full DOT serial of all their tires and write that info down and keep it with other important documents That way if there is a recall you don't have to go read your tires but just review your documents. I have suggested that if you aren't comfortable getting down and trying to find the DOT you find a teenager, give them a flash light and maybe an inspection mirror and have them read the serial to you. It's probably worth a few bucks. You might also read my blog post of DOT date code.

"Dry Rot" is a misnomer for cracking observed on tires, usually more observable on the sidewall. Rubber simply does not rot like an old tomato. Tire age in itself is not a serious concern but it can be part of a diagnosis or predictor. What is of concern is the elasticity, flexibility of the rubber at the belt edges and the adhesion of rubber to the steel in the belts and body cord. The problem is that it is impossible to know for certain, these conditions without doing what is known as a "cut tire examination". This is when tire engineers use power band saws and large cutting equipment (visualize a 12' tall guillotine with a 12" wide 1" thick blade sharp enough to cut paper, driven by a hydraulic cylinder with a few thousand pounds force pushing on the blade) to slice and dice a tire so the above characteristics can be accurately evaluated. In my career I conducted or was involved in many thousands such examinations. We would correlate the external condition of the tire before it was cut with the actual condition of the internal components. While one can never be 100% certain or accurate of a prediction, with thousands of such examinations under our belt we could be pretty confident that our appraisal would be reasonably accurate. Given that you would not want to destroy your tire trying to learn it's internal condition what is done is to use an externally visible condition of degraded external rubber i.e. cracking as a rough predictor of the internal condition. In general the more external cracking the more likely it is that the internal rubber could fail and tear due to a loss of elasticity. However external condition is not absolute as it is sometimes possible to have the external condition be worse than "nominal" if solvents were used to clean the tire or there was excessive exposure to sunlight. This can be observed by comparing tires that spend most of the time in southern states with one side of the RV facing South. I had a situation where the gel coat of the fiberglass side of my RV itself suffered significant cracking from UV exposure. There are other tools such as X-Ray that can identify if there is already a separation of the internal components which is used by retread shops but it would cost you significant time and money to dismount your tires, have them inspected and then decide if they go back on the RV or were scrapped. It could approach the cost of a new tire for the handling and process plus you would be with out tires for a few days to complete the inspection. So this is why we generally use sidewall cracking as an approximate predictor along with the tire age and sometimes a free spin inspection to help identify tires with a suspected internal separation before the tire comes apart. So we need to all understand that cracking is a bit like taking your temperature when you feel ill. An temperature elevated by a few degrees in itself is not going to cause "failure" or death but it is a symptom that can be used along with other symptoms to help your doctor diagnose your internal condition. Is the doctor 100% accurate? No, but with experience and training they can present diagnosis that are probably correct or at least very close. So maybe you can now understand why there is no absolute predictor of "end of life" for a tire based solely on calendar age. We need to use a number of different observations to reach an opinion that has a high probability of being correct.

Yup That's essentially what I posted Feb 2015