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Old 09-27-2017, 11:21 PM   #21
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There are several good reasons to go with 17.5 or 19.5. However, if you select a load range where the minimum psi is for weight well over your actual carried load ... don't be surprised if they introduce undesirable handling characteristics
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Old 09-27-2017, 11:37 PM   #22
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80 psi is what I am running now so they won't be any harder than the 16" tires. Generally handling will improve because there will be significantly less side wall flex on the 17.5 tires.

On my Freightliner straight trucks I went to a higher load range on my last tire change and it made the truck handle much better. A lot less tire squat when loaded also.
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Old 09-28-2017, 01:04 AM   #23
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I feel like just about the only down side is replacement tires are more expensive....well that and the previously mentioned potentially small hand holes. Duallyvalves I suppose make that a non-issue
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Old 09-28-2017, 11:22 AM   #24
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I am hoping the tire life negates the extra per tire price. Nowadays with tire install price about 1/3 of the total cost, longer life tires pay off fast.
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Old 09-28-2017, 11:38 AM   #25
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I am hoping the tire life negates the extra per tire price. Nowadays with tire install price about 1/3 of the total cost, longer life tires pay off fast.


From what I could tell on these forums the actual lifespan of the tire is more determined on date of service rather than wweardue to the degradation of the rubber due yo cracking/rot. Does this change it all with a commercial tire?
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Old 09-28-2017, 01:13 PM   #26
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I can answer this one....based on fairly recent experience standing on the shoulder if I-95, in April of this year

very similar MH with the overloaded rear axle
OEM michelins are date code 0113 and 0213
Yes, getting close to the age of concern, but not quite there....

I don't know off hand the mileage on them, but suffice it to say they barely have the mold marks worn off them

I have religiously kept up the tire pressures based on weight + a healthy margin, and use a TPMS

Anyway
Outer tire curb side went boom, caused a fair bit of body damage.....and it could have easily been much worse. i was lucky on that front.

Yes, generally RV and boat tires age out before wearing out since they are typically low mileage use items....
but when they are overloaded things change a bit.

In my case I'd bet an aggravating variable on top of load is the few curb kisses that tire had seen through its short life. Didn't happen much or often, but I'll admit to turning a bit too close a time or two. Nothing more than slow speed kisses a couple times, nothing severe.

Also, mine has a rear bed slide on that side of the coach, likely making that side even heavier....
Regardless, in my case the tires are clearly a weak link
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Old 09-28-2017, 01:32 PM   #27
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thanks- i have a 28z so a little less overhang but close...
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Old 09-28-2017, 02:24 PM   #28
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A good tire should last 8-10 yrs. That is the issue with the LT rated 16" stock tires, everything I here is they give out after only 2-3-4 years. That is why the investment of the 17.5 seems totally worth it. Plus the danger and the damage of a blow out is greatly reduced. With my business I buy a lot of tires and I always go with the highest rating possible.
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Old 09-28-2017, 02:47 PM   #29
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thanks for the insight.... I have to replace my tires every 5 years anyway (insurance requirements) so it shouldn't be a big problem.
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Old 09-28-2017, 03:55 PM   #30
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Blw2, can I ask which side you had the blown tire? From what I heard the one that usually goes is the back on the passenger side. I guess its from the heat of the exhaust running right there.
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Old 09-28-2017, 09:42 PM   #31
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thanks for the insight.... I have to replace my tires every 5 years anyway (insurance requirements) so it shouldn't be a big problem.


Curious, what insurance requires new tires every 5 years? It's wise, but new to me.
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Old 09-29-2017, 12:25 AM   #32
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Commercial. Rent it when I don't use it.
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Old 09-29-2017, 03:29 AM   #33
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LT tires, when properly loaded and operated, can last over 10 years and 80,000 miles. My Michelins did -- not that it's a good idea to keep them that long.

If tires only last 2 to 4 years with low miles, there has to be other serious issues that should be addressed.
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Old 09-29-2017, 09:07 PM   #34
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LT tires, when properly loaded and operated, can last over 10 years and 80,000 miles. My Michelins did -- not that it's a good idea to keep them that long.

If tires only last 2 to 4 years with low miles, there has to be other serious issues that should be addressed.
Key to that statement is properly loaded. That is the whole problem with LT tires on rv"s is that the tires are overloaded and overheated all the time. Its not like on a pickup truck that you go to the home improvement store twice a year and put a bunch of weight in and drive 5 miles to your house. This is like loading your pickup with stone and driving across the country, several times. LT tires on a pickup have to carry 5-7000 lbs. On an RV they are carrying 15,000 lbs. Big difference. All class A's and super C's come with commercial tires for that reason. Its actually a shame that they still equip class C's with LT tires in the first place.

It's not something you even consider when you are purchasing though, who is really thinking about tires when buying one. Not until you get it home, park it in the garage and see that your tires are squatting before you even put anything of your own in it.
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Old 09-29-2017, 09:48 PM   #35
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There's only a few choices when increasing LR for the recent Ford E chassis... Rickson's happens to provide a wheel offset and bolt pattern in the 17.5 format. Some other truck chassis have a 19.5 wheel by other providers however Rickson was the best or only SRW truck and E chassis provider last times I looked and purchased from them. I'm just glad they exist and provide a consumer type option.

Few people post about real life experiences of making this type of "improvement" to their rigs. I've done it in the past and seriously considered it for the Axis I recently had.

My recommendation is to select a LR based on real carried weight matched to at least near the mfg's minimum psi to weights charted. In other words; best results are when the published scale represents something near the actual weight. A mismatch example is a 2klb tire load on a tire with a lowest psi rating of say 75 @ 3klb+ load. Personally I experienced this combination multiple times where it presented a propensity to have less than desirable handling characteristics on some surfaces (quite unnerving to encounter).

And don't forget as we increase LR and reduce the sidewall we end up with a tire just that much closer to a wagon wheel. So while reducing tire sway and roll is great, it is also a compromise to smoothest ride.
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Old 09-29-2017, 10:02 PM   #36
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Blw2, can I ask which side you had the blown tire? From what I heard the one that usually goes is the back on the passenger side. I guess its from the heat of the exhaust running right there.
Sure.
It was the passenger/curb side outer tire
The tail pipe is on that side but i really don't think that's a significant variable.
It throws off some heat sure, but it's behind the tire and so if anything might be closer to the inner one before it makes the turn out to the side....
I run TPMS and have never noticed a consistently higher temperature on that side.

As a side note....The tail pipe was a big part of the damage from the blowout through. the tread wrapped it and bent it all up under the coach. that was a pain in the neck to fix...literally and figuratively. I nearly had to take it to a muffler shop but in the end was able to get it straightened out enough. I did have to order a new hanger too.
Regardless, as I was wrestling with that, I was thanking the good Lord that it wasn't on the other side, where the sewer pipes are!

My read on it, in what I think is order of importance
1) That corner is very likely heavier than the other side(I hope to get corner weights one day to confirm)
2) axle is slightly overloaded
3) As I mentioned before, I can remember maybe 3 or 4 times when I turned too short and ran up on a curb (cursing myself in the process, that's how I know it wasn't often or very hard) Still, that has to be hard on a tire I would think. Likely wouldn't matter so much on a lightly loaded car tire, but on a tire already overloaded.... Also related to this, it seems that on the shoulder side of roads, there are often more little pot holes and things that wouldn't seem like much but might serve to fatigue an overloaded tire....
4) storage conditions. I don't have the most ideal storage conditions for a tire, parking in an unpaved storage lot. I bought covers for my new tires to at least keep some of the UV off....
5) age, they were getting close to that magic age range of "5 to x years"
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Old 09-29-2017, 11:21 PM   #37
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Quote:
Originally Posted by TyCreek View Post
There's only a few choices when increasing LR for the recent Ford E chassis... Rickson's happens to provide a wheel offset and bolt pattern in the 17.5 format. Some other truck chassis have a 19.5 wheel by other providers however Rickson was the best or only SRW truck and E chassis provider last times I looked and purchased from them. I'm just glad they exist and provide a consumer type option.

Few people post about real life experiences of making this type of "improvement" to their rigs. I've done it in the past and seriously considered it for the Axis I recently had.

My recommendation is to select a LR based on real carried weight matched to at least near the mfg's minimum psi to weights charted. In other words; best results are when the published scale represents something near the actual weight. A mismatch example is a 2klb tire load on a tire with a lowest psi rating of say 75 @ 3klb+ load. Personally I experienced this combination multiple times where it presented a propensity to have less than desirable handling characteristics on some surfaces (quite unnerving to encounter).

And don't forget as we increase LR and reduce the sidewall we end up with a tire just that much closer to a wagon wheel. So while reducing tire sway and roll is great, it is also a compromise to smoothest ride.
I agree about 163% Less sidewall will mean sacrificing some ride comfort, for other consideration... Know what you're buying, and why you're buying it.
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Old 09-30-2017, 10:49 AM   #38
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I don't think 1" difference is 163%, I think you meant 16%. Still will have a lot more sidewall than most new cars today. The 17.5 tires are still a 75 series sidewall, most cars today are closer to 35-45.
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Old 10-02-2017, 10:42 PM   #39
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Finally got my wheels and tires today. I was going to paint them but decided to just put them on instead. I will look at them for a while, I can always mask them off and paint the outsides.

We took it out for a 10 mile drive afterwards and all seemed well. The ride seems about the same as before, if anything we thought it may seem a little better.

Here are some before and after pictures.
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Old 10-02-2017, 10:47 PM   #40
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And the front.
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