Tire Safety

[Gil_J]

Tires are likely the most critical safety items on our coaches that we have control of. Yet, some don't place enough emphasis on maintaining their tires.

Overweight or under inflation are the number one causes for premature tire failure. Do you know the wheel position weight of your tires? If you don't you can't really determine what the minimum air pressure for your tires should be. The tires that share an axle should be inflated to the same pressure. The minimum pressure for all tires on a given axle will be set to the weight of the heaviest side of the axle.

Our tires are speed rated for 75mph and everyone should be driving at less than 75mph. If you exceed 75mph your tires may fail. The failure will likely be due to insufficient pressure for the speed. Here's an interesting article on speed and truck tires (CLICK HERE) (http://www.truckinginfo.com/blog/on-the-road/story/2015/04/too-fast-for-your-tires.aspx)

For those that haven't experienced a rapid air loss in a tire, there's a natural fear of a front tire blowout. This video may put your fears to rest (CLICK HERE for Video) (https://www.youtube.com/watch?v=CseABfJL1FM).

[Joe Camper]

I have a question for those with tire pressure sensors with temp sensing in on them along with pressure.

What kind of temp increases and just what is the temp at 70mph when it's 90 + outside?

[travelite]

Joe,

For many years I ran PressurePro's on my Wanderlodge LXi which had eight Michelin 315's. The steer tires typically increased in pressure from 100 psi (cold at ambient) to 110 psi (hot while traveling 65mph down the highway). This equates to a temperature increase of 50 deg F. If ambient was 70 deg my tire warmed up to 120 deg F. If ambient was 90 deg the tire warmed up to 140 deg F. Pressures increased by 10 psi which is what you'd expect; i.e., theory says you should see a 2% pressure increase for every 10 deg increase in temp.

My Prevost H345 has 365's on the steer and tag, but I'm not running any TPMS, so I have no insight into how the 365's behave. Judging from my IR Thermometer and rest-stop pressure readings they look to run about the same as my LXi's 315's.

[Gil_J]

Michelin says a 10-15 psi increase from cold to driving is typical. I've seen closer to 20 psi at the extreme. I bet anyone crossing death valley today, at 130 degrees, will be testing their tires.

[Joe Camper]

Pressure increases r more than that. My pressure pro used to measure 20 25lb increases on really hot days.

I also noticed how quickly they come down too. As u hit exit ramps if u monitor pressure just prior to pulling Into a rest area they r down by half the amount by the time u get parked and set the brakes.

I'm curious about what temperatures r on a hot day.

A heat gun after stopping is not a real good representation of temps rolling down the road either, if they drop as quickly as pressures do.

Gill IMHO anyone going across death valley during a 130 degree day, unless in an extreme emergency would be just plain dumb. If u need to get across go at night.

The only time I came across death valley was a trip back from Pendleton to Chicago in a 73 Cuda with a cam and a gear. It was the middle of the night and I just barley got through without overheating.

[GoneCrazy]

After learning about Steer tire blowouts and how serious they can be. I opted to have the Tyron safety system installed on My new steer tires. I had to sacrifice some of My bling upgrades like LED marker lights had to go on the back burner. But they can come later. At least now I have a comfort level should I ever have a incident. I also have the new TPMS pulse to monitor and detect a problem before it occurs. The Tyron's are expensive , But just a drop in the bucket in the whole scope of owning and maintaining one of these elegant beasts !

[Gil_J]

Rocky,

I broke down and decided to do the 365 upgrade on my steer tires just to increase my margin of safety. I just got the tires yesterday and still need to get the studs changed.

You said the Tyron rings are expensive. How expensive? They must be heavy duty. Keeping that heavy tire out of the center depression of the wheel can't be easy.

I went with Truck Systems Technology's TPMS system for trucks instead of the RV system. Their customer service and product are great. They even have internal sensors.

I hope you never test your Tyron bands. If you do, let us know how it goes.

[travelite]

Pressure increases r more than that. My pressure pro used to measure 20 25lb increases on really hot days.

If you really control for all the factors like increases in ambient throughout the day, direct sunlight, inclement weather, and changes in altitude you'll see 10 to 15 psi increases. All of these confounding factors can add to the increase. I used to do my testing at night time on flat ground in the dry. I wanted to isolate the temperature and pressure increase strictly due to the tire warming up. 10 to 15 psi is it, and in my case it was 10 psi increase and a 50 degree F. increase for a warmed up tire

[Joe Camper]

Dave if u went up 15 at night on flat ground that's not a good look when u r driving during a hot day in the mountians. I think the increases I saw were up I-65 flat straight road during the heat of the day, and I had a 40 ftr that was not a heavy bus.

[travelite]

My bad Joe, I think I misunderstood your question. I thought you were asking what the warm-up temp and pressure increases would be at an ambient of 90 degs with all else remaining the same. But, I think what you're asking is what do folks typically see in pressure and temp increases during their usual trip through various conditions.

See, I had a Wanderlodge and it earned its name! I spent countless hours fine tuning the ride and handling. You name it; I did it, and tire pressures were very much a part of my experiments. In order get a good understanding of what truly was happening with pressures, so that I could run on the hairy edge of manufacturer's pressure recommendations, I needed to know what the warm-up increases were under controlled conditions. With this understanding I wasn't shy about bleeding air out of hot tires. I knew how much pressures were expected to drop as ambient temps went down and I knew how much they were expected to rise as I crested Eisenhower Pass. I found if I could maintain my hot pressures at 105 psi my Wanderlodge ride was much closer to the bus I thought I bought. After 10 years of this I said, "Get me a Prevost"! LOL!

BTW, I didn't see 15, I saw 10.

[Joe Camper]

Yup. I had the smaller 12 22.5 and only had to put 100psi in the steers.

I often wondered about the conversions with the 315 80s that need 110 psi cold for the given steer weight and just how high those pressures go in the heat of the day...... gotta be north of 125 and that's a stiff tire.

If u r one who fits this description keep those speeds down in the heat for sure.

[TheGadgetGuru]

I have a question for those with tire pressure sensors with temp sensing in on them along with pressure.

What kind of temp increases and just what is the temp at 70mph when it's 90 + outside?

Hi Joe,

I'll be reunited with my coach after the holiday and I'll be happy to check that temperature for you. However, the Prevost TPMS is placed at an angle where it's not that easy to read the small numbers while driving as it's prone to glare. So, if I can do it safely, I'll try to remember to do it for you.

[GoneCrazy]

Gil,
Not sure on the actual cost for them now. I had Mine lumped in with a lot of other work. But I would guess around 2500-3000. Please post a Picture or two of Your TPMS Monitor ? And how do those internal sensors mount ? What is the cost of that setup ? I got My Tyron's at Jeff's place / ETLC . He is a dealer for them now. After watching the Tyron video's a few times , It looked like a No Brainer to Me.

[Gil_J]

Thanks Rocky,

I went with TST's commercial vehicle system. It's suppose to be more robust than the RV system. I should say, I went with a hybrid system. They sent me the display unit for the RV that has a rechargeable battery instead of only being hard wired. They were so easy to work with. When I ordered the system they wanted to delay my order for 2 weeks because they had a few sensors in the last run that the battery seal would leak in heavy rain. When I said I was about to start a trip they sent me the suspect sensors and then followed up with sending me a complete new set when they were available. I mounted the repeater in a bathroom closet and haven't ever had a communications problem.

I'm doing a 365 front tire upgrade now and wanted the valve stem mounted internal sensors. These were discontinued because the number of SKUs would have been too great and some people where trying to make the available ones fit where they weren't intended. Although not on their web site yet, they went to internal band mounted sensors. They didn't develop their own band they used the one that is sometimes used on Corvette wheels. I'm not a fan of the banded sensors, so I stuck with the external sensors. BTW, the external sensors required a 1/2" longer valve stem on the new wheels.

Here's a link to the system I have. BTW, TST was just acquired by an air products company that focuses solely on the trucking industry. That should say something about their product in a commercial trucking environment. This system was also much less expensive when compared to the Pulse.
https://tsttruck.com/product/4-tire-pressure-monitoring-system/

I did some research on the Tyron system and am just not sold on there value yet. I can't find any OEM that uses or recommends them. The only fleet I read used them was a police department that later removed them. I also read a couple of stories where the bands came off in the wheels. I'm not suggesting they aren't a good safety investment, just that I'm not yet convinced.

[GoneCrazy]

Gil,
I have read that insurance companies give a cheaper rate with the Tyron bands installed. I have not asked My agent for a discount yet. I just read that a few minutes ago. Marathon now installs them on their new coach's. As a pricey option I am sure. There are a few issues that I can see might be a problem with them. 1) The tire has to be balanced. I used Centramatics. 2) Tire maintenance on the road. Tyron safety band removal kit is about 150.00 , And any dealer that installs them. Should insist that this kit stay with the coach in case of emergency tire maintenance is required. It has tools and instructions to remove and re-install the bands.
I did read about one gent that had a band come loose inside of His tire. I do not think that is a common occurrence. But a case of human error by the installer. Just like anything else. Tyron will replace Your Alcoa wheel if it is damaged from a flat with the band installed. Like You said , I hope I never have to test them !
Safe travels..........