Do you have or need a spare?

 Reasonable question. I have previously published some information on having a spare HERE, but for those that want a quick answer....

Most Motorhomes already have receiver for hitch so adding a spare carrier there should be relatively easy. Amazon has some and I have seen smaller models starting at $40.

One way to cut cost is to put one of your old tires under a cover as a spare.

Used wheel from junk yard should also cut the cost.

Re: Tire cover. I would consider a WHITE cover a necessity unless you want to bake the life out of the spare mounted outside the RV.

RE jack & tools. Be sure you know what you are doing and have all the tools you might need including flat board & steel plate if you need to jack on soft ground. If you don't already have the tools I suggest Harbor Freight, as hopefully you will never need the tools and if you do they will not get much use.

 Will you be able to physically lift the tire and mount it on the RV? You will need correct 6 point socket and a 2' breaker bar and if you have a Motorhome with dual tires in the rear an extension. You should practice at home so you know how much effort is needed.

 

Here is a YouTube one guy made. Your system may be different so after watching, you can go and do a practice on your RV.

 

Even if you can't do the physical job having a spare will probably pay for itself as any road service should be able to change the mounted tire so you are not confronted with having to buy a mismatched new tire @ 2x the normal sale price.

What size spare tire?

 There have been a few people ask about what size spare they can use. The easy answer is simply use the same type, size and Load Range as the tire you are replacing. BUT for some this may not be easy to do. Lets look at a few scenarios.

1. You have a trailer with ST type tires. Your only option is an LT type tire or wait for a few days. Now I don't have any personal experience with needing an ST tire in a rush. The one time I needed to replace an ST tire on my race car hauler, I already had a spare. I decided I could wait till I got home to buy a replacement. So my advice to trailer owners is to carry a spare. When you do I advise you either keep it in a storage bay or under the trailer or under a white vinyl cover to prevent the Sun's heat from damaging it. The spare doesn't even have to be a new tire. Just be sure it is inspected inside and out. I would also suggest you keep the inflation low (10 to 20 psi) and be sure you have a compressor available. However, if I simply had to continue on my trip and had no spare, I probably would have bought an LT that had a load capacity that was greater than the original ST. This would have been either larger in size and or higher in Load Range. While the axles would have looked strange with one tire being larger in OD, I felt that I could continue if I simply dropped my travel speed to the 50 - 55 mph range.

2. You have a Motorhome with same size front and rear tires that have significantly different levels of wear. This requires a bit more work. With duals on the rear it is critically important that you have each tire in the pair of duals, matched in size and load capacity. I covered how to match tire OC in dual position HERE and HERE. If you can't get a tire that allows you to have a "matched" pair, it might be possible to take the two fronts and use them as a pair and have different size tires on the front till you can get to a tire dealer. 

3. Your motorhome has different size fronts and rears. This presents other problems, especially if the fronts are much larger. There is a critical dimension called "Dual Spacing" that needs to be considered. Learn more HERE. I suggest you spend a few minutes now, while you are calm, and review your tire sizes. You can learn the Dual Spacing for your tires by consulting the dimensional information on the web site for your brand tires. THIS post shows how you can measure and confirm your current spacing. Knowing what you have and what you need can answer the question of what you might be able to do in an emergency. You might discover that you need to review your situation with your tire dealer. 

4. Another fly in the ointment involves your wheels. Many Class-C motorhomes have identical steel wheels in all positions but some Class-A motorhomes may have both steel and aluminum in the rear dual position and you may have to have tires dismounted and switched around as not all wheels can be used as both inner and outer in dual position.

Depending on your situation you may have no choice but to be towed to a truck stop where you can wait to have the correct tire delivered.

You may find that you need to review your options with your tire dealer as it would be better to know your options now rather than make an expensive and incorrect decision on the side of the road while under pressure.

Spare tire - mis-matched size What to do?

Class-A owner said:
"I use to advocate carrying a spare in my 2005 Monaco Diplomat. On that coach, it used a short 22.5 tire and it fit in my pass thru bay, unmounted. I could stuff a lot inside the tire and didn't lose much storage. Fast forward to my current RV and the 315's won't fit in a bay.

So......a lot of people say to just carry a spare, including a trailer owner with a rear mounted spare. It's nice to say and actually nice to carry a spare if you have room, but if you don't have the space, you need another plan. That plan is to have a roadside service plan and be willing to accept an odd sized or used tire to get you back on the road. Wait until you're in a major town on a weekday to resolve the issue with a new or correct size."

My reply:

While using an "odd" size on the front might get you moving (slower) mismatched duals will mean the larger OD tire is carrying more than design load.

I would limit the speed to 50 or less and be prepared to scrap BOTH tires as the internal structural damage is impossible to "inspect" for.

If you have two different size tires on your RV and can only carry one I would suggest the rear. Hopefully, you have confirmed your actual load on each tire position and have some margin available on the fronts. If you are running at 100% front capacity (bad idea) then the use of a smaller "rear" tire as a temporary front means you really need to limit both speed and distance you operate in that situation.

Overload does not always mean tire belts will overheat and a warning is received from your TPMS. The steel sidewall ply can fatigue from over deflection and you will have no warning and not know it till the sidewall fails catastrophically. 

All the above brings up the question of why did you have a tire failure in the first place?. Have you read THIS post.

A properly programmed TPMS should provide an early warning as soon as you lose 15% from your "set" pressure (slow leak) or 3 psi from your hot pressure within a couple of minutes (fast leak).  If you are also having a tire professional do a close and thorough inspection every year starting at 5 years for Class-A and Class-C or at 3 years for any trailer, it is unlikely for you to develop a belt separation without some advance warning.

Taking precautions is always better than trying to "fix" the tire after you have a flat.

NOTE. The above in no way should be taken as a suggestion that driving on an overloaded or under-inflated tire or mismatched duals is a safe thing to do. I am just offering suggestions for possible responses in an EMERGENCY situation where you feel you MUST move from your current location to a safer one.

Another question on having a spare

Was reading another RV Forum thread on spare tires. The questions about cost and difficulty in actually doing the change came up. One person said a spare for his Ford Transit van (Class-B?) would cost $400.
I offered the following.

A little shopping around and you should save a lot. New steel Ford transit wheels are available for $70 on eBay. Probably $25 at a local junkyard. Remember Class B and C RVs are basically just large pick-up chassis and there are thousands of those in junkyards. Also, a steel wheel is fine for a spare.  Used tires usually go for $25 to $50. A spare only needs to be good for 50 to a couple hundred miles so again a few phone calls to local tire dealers and you should be able to find an acceptable spare, especially for Class-B or Class-C. Class-A owners will need to check with HD truck repair shop.

You need to be a bit creative and not simply go to your RV dealer and ask for a new tire & wheel. Very few RV dealers are in the business of selling tires & wheels and if they are, they probably only have new tires.

What I am suggesting is that if you have to buy a tire from the service truck, on the side of the road, the price will probably be 125% to 200% of a sale price.  If you have a Class B or Class C most people should be able to do the change themselves with a little planning and preparation.
Planning and maybe even practice on a nice sunny afternoon would be a good time to confirm you have all the tools and supplies (like a solid platform to place under the bottle jack if you are on dirt)
 
 Class-A can save time (hours or days) and maybe $hundreds and space by being able to provide just a tire that fits their RV. HD Service Trucks are equipped to change and inflate a tire on the side of the road. If you have different size front and rear I suggest you have a spare for the rear as they suffer a higher percentage of punctures than the front.

##RVT880

Do you need a spare tire?

Just read a tale from a Class-A owner who suffered a sidewall puncture on a weekend and had serious difficulties getting service or replacement tire even though he had been paying for RV Roadside Assistance.

I have posted about spare tires on this blog and on various RV forums.

One thing almost no one considers when shopping for a new RV is the potential need for a spare tire. After all, lights in the ceiling seem to be more important to many as is having 3 televisions

The assumption that having "Roadside Assistance"policy is good enough, many times does not work as well as the advertisement.

Competent truck tire service centers have the ability to change tires at the side of the road but it appears that the insurance companies (ones selling the idea of assistance) are really only knowledgable about cars.

I have suggested that if you don't have a spare you should be able to get a used tire, in your brand, type and size and find some way to carry it around. Used tires should cost closer to $50 for 22.5 sizes and if you know a fellow RV owner who is getting new tires I bet you can make a deal.

Having a tire only, would allow a regular truck tire service truck to come out, mount, inflate and change the tire. You still will need a new tire but you should be able to get a better price on a new tire somewhere in the next couple days when you have time to do some shopping around.

Your "old" spare tire should be thoroughly inspected but should be OK for a few hundred miles at 55 mph max on a rear dual position.

Why don't tire companies make more tires of the size I need?

I have noticed that every now and then people post variations of the question above. This happens because they have decided it is time to replace the tires on their RV and with only a few weeks before they expect to travel they discover that the size they have is "Out Of Stock" and "On Back Order". Sometimes they discover that there are a few tire dealers with the size they want but due to the shortage the rules of "Supply and Demand" have taken over and the price of the few tires that are available has gone up by 25% more than a no-name brand or maybe 50% higher than the normal price for a tire of a specific brand. So I decided to do a little investigation.


Lets put the RV tire sales volume in perspective.
In 2014 there were about 310,000 trailer sales. A majority of these came with ST type tires and some with LT type tires. While I could not find specific figures I believe that almost all ST type tires were imports. I would estimate this represents almost 1 Mil. OE tire sales

In the motorhome market I think it's reasonable to assume that Class B and Class C basically use LT type tires. There are some exceptions such as the new Super-C class but these are not broken out in the data I could find.  These two type RV would represent about 130,000 LT tire sales.

Class-A with about 22,000 units produced probably represent OE sales of about 140,000 total spread over maybe 15 sizes and Load Ranges. I am certain some sizes are relatively common and popular with a few that may represent 20,000 units in total annual sales and potentially a couple sizes with as few as 1,000 tires a year.

Clearly the low volume needs of some Class-A sizes is where the shortages in supply develop. I have never heard of anyone having problems finding a 16" LT tire which is probably 95+% of the Class B & C market spread over fewer than 5 to 8 size & Load Range variations.


Now to tire production:

First off a little background is in order. Tires are basically made in batches of a couple hundred to a few thousand tires, then the manufacturing plant switches to a different size or design. The only exception to this would be in OE passenger or Light Truck items that are scheduled for delivery to a major car or truck manufacturer. Lets look at the numbers so you will understand why this is.

In the US there were about 7.6 Mil cars and 8.7 Mil light trucks and 400 thousand heavy trucks produced in 2014.  There were about 253 Mil. passenger tires plus 33.6 Mil. LT tires and 23.1 MIl medium and heavy truck tires sold at replacement and OE. These figures include import tires. So you can see that Class-B and C combined represent about 1.5% of the LT market an Class-A size tires represent less than 1% of truck tire production.

When tires are made they are cured in molds that cost $30,000 to $100,000+ with truck sizes being at the high end of costs. Companies also need cure presses as seen in this video on tire production

You can click here to see the 7 min video on truck tire production and the press in operation.

The press holds the molds and the press system can cost upward of $1 Mil each. It also may take an hour to cure each tire so a balance needs to be reached between cost of molds, press utilization and production volume. I think you can understand that tire companies don't want a large number of very expensive molds or curing presses just sitting around and not being used so scheduling of production in the 7/24 curing room operations is very complex.

So why do people have problems finding a specific size from a specific manufacturer. It's simply a matter of scheduling, equipment utilization and priority. A tire company may have two molds in a specific size available and can produce about 40 tires a day in one press with two molds. They may schedule just one weeks production to build and cure 200 or so tires in a single batch than move to a different size/design tire. Don't forget your annual sales is only 1000 units a year and your customers do not want tires that are more than a few months old so you probably limit production to a single week every other month.

I would suggest that short supply of a specific size for an RV application is the result of the RV company's choice to go with a low volume tire and not a desire on the part of the tire company to make customers unhappy. From the comments I see it is always the tire company that gets blamed for a shortage in supply of a specific tire as no one ever seems to hold the RV company responsible for their selection of a hard to find size.

If you were a tire company where would you focus your production efforts on RV tire sales that represent less than 1% of your total sales and then on a specific size that is less than 5% of the RV market?

Maybe a better thing to do is to think about tire size availability when you make a RV buying decision. This can also have an impact on your ability to get a replacement if you get a puncture while on the road and your need to carry a spare which I mentioned in this video.

As I suggest in the video, have you bothered to check on the ease of finding replacement tires in the size and Load Range you want BEFORE you are in need?


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Can I mix Load Range ?

There was a question about mixing tires of the same size & design on an axle if the Load Range is different.

First we need to all understand what is meant by "Load Range". The official definition as published in the Tire & Rim Association yearbook says "Load Range with a letter (A, B, C, etc), Standard Load, Light Load and Extra Load are used to identify a given size tire with its load and inflation limits when used in a specific type of service, as defined in the heading of TRA tables".

Basically "Load Range"identifies the max inflation for that specific size and type tire and the load capacity of the tire when set to that pressure. many think of it as Ply Rating 2, 4, 6, etc. I previously covered Load Range and Ply Rating in THIS post.

But what do you do if you have to replace one tire on an axle because of some failure like a puncture, impact or even a "Blowout" and can find a matching tire of the same size and type but of a different Load Range?

If you are replacing the failed or damaged tire with a higher Load Range you can run it as if it was of the lower Load Range.

Example 1. You have an ST225/75R15 LR-C and can only get a LR-D.  Your Placard indicates you should run 50 psi cold. Since you know you should always run all tires on any given axle at the same pressure your only option is to inflate the LR-D replacement to 50 psi. Later on you may want to increase your RV load capacity so you may want to get another LR-D and then inflate both tires to 65 psi which will increase your load capacity of the tires by over 300#
 BUT you need to confirm the wheel is rated for 2540# and 65 psi. You will need to contact the wheel manufacturer to confirm the wheel is so rated. I am not sure if i would accept what either the RV dealer or even the RV manufacturer says as they might not have all the engineering data or have other reasons to state a lower capacity.
You will also need to confirm you are not overloading the axle or springs or frame by increasing the load.

There is another reason to increase the inflation but not increase the actual load beyond the original max of 2150#. By running the tire at the higher inflation you are giving yourself a larger "Reserve Load". Some consider this like a safety margin. By running the higher inflation at the lower load you will also decrease the internal structural loads the tire has to tolerate and this should give better durability.

Example 2. Your RV placard indicates you should br running 255/70R22.5 LR-H but you can only find LR-G. In this case you are really out of luck unless you know for certain that you have less than 5205# load and not something any higher. The LR-H tire is rated to carry 5510# at 120 psi while the LR-G is only rated for 5205# at 110psi. This may not sound like much but you should not run your tires in overload as you will do structural damage to the tire which could lead to a reduction in life and even a tire failure under some conditions.

If you are running the highest Load Range for your size you may want to consider carrying a spare tire and let the road service mount your old used spare to be used to get you off the highway. This way you will not be spending hundreds of dollars for a tire you can only use for a few miles.

How do you change a tire?

Have you ever given this question much thought? Your answer will depend on your answer to a number of very important questions that need to be considered first.

1. Do you have a spare? A lot of RVs don’t have a one. Their only option is to call a service and hope the service company has the correct size.

2. If you have a spare, is it inflated? Given the number of folk who seldom check the tires already on the ground a majority simply forget to check the spare or don’t check because it isn’t easy to do.

3. If it’s inflated, do you have enough pressure to carry the load for the position where you are going to mount it? You probably need to be sure you have the spare inflated to the max on the tire sidewall so you can bleed it down to the correct amount for the position.

4. Do you have the necessary tools? Wrench, sockets, long breaker bar, jack, jack stand, steel plate to support the jack, Safety warning triangles, flares, and lighting to see what you are doing in the dark? How about waterproof tarp to sit on while doing the job? The steel plate needs to be big enough to support the jack if you didn’t park on a hard road surface.

5. If you think you have all the correct tools, have you made sure by actually unbolting a wheel?

6. Do you have the strength to loosen and retighten the nuts? Have you ever actually tried to loosen all the lug nuts? Do you know the torque specs? Do you have a torque wrench that is big enough for your RV? I have a full toolbox and air impact wrenches in my shop but I doubt I could loosen the nuts on a Class-A. Just watch the first 45 seconds of this sales video and ask yourself if this would be you? Note I am not endorsing that product. I just liked to see the guy jump on his wrench


One other thing to consider. If the nuts have been on for a few years there is a good possibility it will take much more than the OE specs to loosen. I have broken Craftsman and SK sockets on passenger lug nuts because they were put on too tight.

7. Finally do you have the strength to lift the tire & wheel to get it on the wheel studs?

I suggest that if you think you are going to change your own tire you need to do a few things.

1. You need to pick a nice day and with the RV level and the jack stand on a hard surface, first just see if you can loosen all the lug nuts and then re-tighten to the factory specs. Don’t do just one nut or one wheel but do them all. Be sure to have someone around watching just in case.

2. See if you can move the spare out of storage and to get it back into storage again.

3. Remove the inner dual and put it back on again.

4. Most important be sure you clean the threads and torque the nuts to proper specs.

5. Ask yourself if this is something you want to do while at the side of an Interstate In the rain, at night?

If you don’t feel up to the job you will need to plan on having a service do the job.

If you don’t have a lot of space for a spare tire mounted on a wheel you might consider having a used tire of the correct size just in case the service company doesn’t have your size. If informed most can do a tire change for you and you will save some big bucks too. You can always pack stuff inside the tire if there is no wheel.

Finally be sure to check the air on the spare every month, even on your toad.

##RVT887