Tire PSI - Cold vs Hot

[Morich]

For quicker and easier when not needing new tires, I found mounting the sensors on solid mounts so that they were not flexing the stems was an easy way to go.
We went with the simple to install screw on that replaces the valve stem caps and then to make it secure I used L-brackets to pop rivet to the wheel simulators.
I then was able to stop doing the dirty job of getting down and checking each tire for pressure as it and temp were displayed on the dash monitor.

As I turned the monitor on and it began to poll each sensor, the sensors would then "wake up" in response to that polling and begin to report in. That would often took as much as 4-5 minutes, which often was spent doing the other things needed to get ready to move, like winding up the hose and cords!
As part of checking and putting in the GPS info, it was easy to just look at the monitor to make sure each tire had woke up and reported as good .

The amazing part was how much the parking position changed the tires and that totally threw out the idea of setting the pressure before moving. At home we park with one side next to a board fence and those tires were different temp and pressure than the side in the sun, so if I went to the trouble to set each tire as matching the others, it would have assured me that they would be different pressure when we got 5-10 miles down the road!
I stopped chasing that worry and let the tires do the talking! The one I never got under control was the inside right rear dual which had the exhaust blowing on it!
But when I ran over a bolt in construction zone between Houston and Baytown, the alarm went off and we stopped to find it sticking out of the right rear inside dual.

I really doubt I would have ever crawled under there to spot it, so I feel the TPMS likely kept me from running long enough to blow the tire.

It cost me some time and money to replace the tire but I had no tow bill, no body damge and did not have to risk wrecking the whole thing when the tire blew on the interstate!
That hundred or less spent, saved me thousands and possibly our lives!

[No1Hunter]

For quicker and easier when not needing new tires, I found mounting the sensors on solid mounts so that they were not flexing the stems was an easy way to go.
We went with the simple to install screw on that replaces the valve stem caps and then to make it secure I used L-brackets to pop rivet to the wheel simulators.

Can you post a picture of what you did? For the life of me, I can't seem to picture it in my head.

[Morich]

No longer have an RV and no pictures but some changes would be needed for different wheels so maybe an explanation will do?

The idea is that we can mount the sensor in/on the wheel when we change tires, or we can use stem mounted sensors and screw them directly to the valve stems. The problem with mounting then on the stem is that as thew wheel turns it adds a lot of stress to the stem and likley breaks it!
But if we want to avoid that trouble, we can use flexible valve stem connectors and mount the sensors on the wheel simpulatorss, ( the funky , lightweigth hubcaps?) with pop rivets and angle brackets!

Some sets come with angle brackets but I had scrap aluminum L metal and cut my own to fit as needed.
Depends on shopping and what you find that looks like it would get the sensor out where you can deal with it but make it solid so it doesn't swing around.
It can be argued that the extentions add a potential trouble point but I screwed them tight and had no trouble over the years we had the RV.
RV without the wheel covers may need a different setup but they have spring mounting that might work well for those without handy covers for ease of working. No experience with those!

This is a different system for truck use:
https://www.amazon.com/bestautoparts...954179087&th=1

[No1Hunter]

The idea is that we can mount the sensor in/on the wheel when we change tires, or we can use stem mounted sensors and screw them directly to the valve stems. The problem with mounting then on the stem is that as thew wheel turns it adds a lot of stress to the stem and likley breaks it!

That is why I said I am going with metal valve stems in the future.

[Morich]

It kind of gets down to what we want to do but adding the sensors and safety now or waiting till we want to change tires is where I came down to doing it sooner rather than later. It's all a calulated risk and when I looked at going with metal stems and not having the sensor tied down, it seemed the amount of torgue put on the sensor and the metal stem was not leaving me feeling good as even the metal is prone to breaking with that much torgue put on it at highway speed.
A number of other small factors went into my thought.
One thing I wanted was to place them where I could get to them easily and on my wheels that seemed unlikely with a preformed metal stem as the angles to get it out from behind the wheel sim and where I could see and work with it never seemed to fit as the angles were really hard to fugure where it would leave the sensor, so after going back and forth to the store, measuring and trying to fit one, I decided just going with the metal braided flexible was what I saw on trucks and decided if it works for the miles they drive every day, it was okay for my small time use.

But part of that was having the tools and parts to do the work cheaper and much quicker than finding the parts that seemed to fit. Being a much more common item, made it possible to just walk in and look at what was needed, take it home and if no good, I could do the swap in such short time that I just felt better about it than ordering and waiting.
I probably spent more for the part locally but I also was able to get the full job done much quicker! Sometimes speed is not only in the work but getting the decisions and purchases done.
I looked at lots of trucks as they use them far more and should know what works best and flexible lines and solid mounts is what I see there so I felt better going with the "standard" rather than the RV option!
Just trying to find a metal stem that fit for the duals was turning out all wrong as they never seemed to go inward and then turn to come out at the right place on my wheels.
Possibly those I was finding were meant for the much larger truck tires, but I was not finding it right for what I wanted but I'm sure that fits different on different RV.

[BobC]

The best option for extending your valves is to replace the existing valve stems with metal "extended valve stems". These mount to your wheels and replace your existing valve stems in their entirety. A well-regarded brand is Borg:

https://www.shinyrv.com/product-cate...s-mfg-by-borg/

These are much more secure than "valve stem extenders" that screw on to your existing valve stems.

The downside is they require professional installation in that the bead of your tires need to be "broken" to allow access to the inside of your tires. The tire doesn't need to be removed from the rim.

This is best done when buying new tires. Otherwise there will be an installation cost/tire. I had mine installed with new tires so installation was free. Otherwise, I've seen installation costs quoted in forums as being between $25 and $50 per tire for existing tires so shop around. If you plan on getting new tires in the foreseeable future, you can use the screw-on extenders until then, but make sure they are firmly secured at the outboard end. Even with screw-on extenders, metal is preferred. Here's a video on installation of metal screw-on extenders:

https://youtu.be/SxsZiJ7T3bM

[Morich]

That's where I was finding changing the stem at the tire was going to do one of two things. The mounting was going to put me off on being safer for several years as we have never worn a set of tires to the point of change needed but juist aged out OR the labor involved was going to be far more than the TPMS equipment.

So the question became this choice.
Should I run to get tires mounted and the "best" valve stems installed and pay far more or should I put off safety?
I looked at the slightly less reliable option of having the safety NOW at far lower price.
We sold the RV and removed the TPMS before we ever had any more tire work done, so I consider that I chose the correct move for us at the time!

Had we installed the sensors in the wheeel, we woulc have lost them when selling the RV, but since they were surface mounted we unscrewed them and sold them as used for almost the price we paid as the TPMS market valvue has gone up so much!

One of the big things we find about RV is that there is rarely one single method or action to fit everybody.
Sometimes the trick is being able to know and deal with ourselves!

[backtrack15]

I used a small section of stick-on high density foam to support the TPMS units on my trailer (to keep the stems from flexing too much). I figured I’d swap to metal stems when I changed the tires.

[wyocamper]

Eeztire sensors weigh 22g, or about .8oz. I don't think it's enough to cause a lot of extra flex on the stems.

[backtrack15]

Originally Posted by wyocamper

Eeztire sensors weigh 22g, or about .8oz. I don't think it's enough to cause a lot of extra flex on the stems.

Yes. Those rub marks on the outside of the rim convinced me otherwise (which is why I added the foam).

[Morich]

Originally Posted by wyocamper

Eeztire sensors weigh 22g, or about .8oz. I don't think it's enough to cause a lot of extra flex on the stems.

I feel this is not true as the lead wheel weights they use to correct balance are not heavy but if we lose one we certainly notice the difference.
A half ounce at 15-18 inches out from the center get really hard to hold at 60 Mph!
As an experiment, try holding a weight like a pound near your chest while spinning around, then try holding that weight out to arms length and spin around to see how much difference the distance out makes in the perceived weight and the pressure that weight puts on you. Can you imagine the extra if you were a tire spinnning when going 60 and how often and hard it flexs after an hour or two?
Did you ever figure why you could stay on the merry-go-round at the center but the kids on the outside fell off?

Or if you have one of the small turntable spice racks, or even an old record player, try putting a salt shaker near the center and it stays but if you put it out near the edge, it flies off almost immediately!

I'm sure some of the science guys will have the proper name for it and possibly a formula to use but if you were paying attention when you were a kid, you already know!

[BobC]

Getting back to your original question about tire temperatures, Roger Marble, aka Tireman9 is a retired tire engineer and Winnieowner has a blog, "RV Tire Safety" that will give you a ton of information on the temperature topic and many others:

https://www.rvtiresafety.net/2011/03...and-roger.html

I keep it bookmarked for reference any time I have a tire question.

[Scotty B]

bit of a related question, but maybe not so much.
I need to have the engine running when I use my Viair compressor. I have been inflating/deflating as necessary every two to three months on our current Adventure (and Adventurer!)
Does it matter if I do this while camping - slides out and jacks extended - or should the tires be supporting the full weight of the coach as driven? Guess this is more about the jacks than the slides, but figured I would throw them in as well.
I have been doing this after we have broken camp and retracted the jacks/slides - right before we departed, but would like to do it on our "river ready" day - the day before we leave while still set up.
Thanks!

[Morich]

This is where I got down to not being so concerned with getting it right as there is no way for them to stay"right! as we drive.
Just the basic idea of testing when they are cool is opento being far different for different folks.
I know what they mean but I've also come around to knowing that cool is far different in different parts of the country.
Since the pressure is not specified if they mean cool as in Minn or cool as in Arizona, I come down to thinking it is a somewhat generic recommendation that has a lot of slack built in and that leaves me thinking I will no longer try to stay up with tire pressure that may change from morning to night each day or as a weather front moves through.

One of my first "wake-up" calls was an actual wake up as the alarm went off in the early morning when the temp dipped! I had the alarm setting too fine for real life temperature swings in the tire pressure and had to open it up a bit to avoid either alarms overnight as it cooled or after a few miles of driving as they warmed.

[RocknRoll]

Originally Posted by No1Hunter

When I get my tires changed out, I will insist on metal valve stems rather than rubber. They are much better. In fact, if you use the TPMS flow-through senors, they are required.

That is something I never thought about. Great tip!

[reeman]

Most important check is watching for deformation of the tires. Checking pressure is always the first step but watching for any possible overheat and deformation of tires is just as important.
One can have proper inflation and that means nothing if the tires are damaged. Any bulging or lateral distortion for any reason cannot be ignored.

[Lette]

Good reading but I still have a question.....I just purchased new tires for my Winne Vista 31be and now have Michelin 245/70R19.5 XZE tires installed. I'm about to purchase the TST TPMS system as a monitoring system but my question is.....

Although the Winne calls for 82 PSI COLD, the MICHELIN tires call for 120 PSI COLD.

I currently run them at 85 PSI COLD. What am I missing or mis interpreting ....

[No1Hunter]

Originally Posted by Lette

Good reading but I still have a question.....I just purchased new tires for my Winne Vista 31be and now have Michelin 245/70R19.5 XZE tires installed. I'm about to purchase the TST TPMS system as a monitoring system but my question is.....

Although the Winne calls for 82 PSI COLD, the MICHELIN tires call for 120 PSI COLD.

I currently run them at 85 PSI COLD. What am I missing or mis interpreting ....

So, are these Michelin like kind replacement (16 ply) of what was originally on it or an upgrade? Personally, I would go with what the tire manufacture states.

[Scotty B]

Always multiple opinions...think most will say go with what the coach says as it is specific to the weight of the coach. You could max out the tire as per it's sidewall info, but it will be so hard it'll rattle your fillings loose. The deal is that the sidewall info is for the max weight load for the tire. Your coach comes in far less than that.

[No1Hunter]

Originally Posted by Scotty B

Always multiple opinions...think most will say go with what the coach says as it is specific to the weight of the coach. You could max out the tire as per it's sidewall info, but it will be so hard it'll rattle your fillings loose. The deal is that the sidewall info is for the max weight load for the tire. Your coach comes in far less than that.

Thus, the reason I asked about the tires. If it originally came with 16 ply tires, then go with what the coach says. If it originally came with 12 or 14 ply, maybe not. With limited information, it is really hard to say.

Keep in mind, underinflated tires are just as dangerous as overinflated tires.