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RE: 5th Wheel Tires
Thanks to all for the replies. I plan to have the trailer weighed. However, except for Goodyear "G" rated tires I have the largest, most durable LT radials on it. Time will tell if they hold up. The info was on the inside of the kitchen cabinet door. (Dry Wt. 10404, Hitch Wt. 1600 lbs., Dry axile wt.4402 lbs., GVWR 12720 lbs., Ld Capacity 2316 lbs. Lngth 32'7") This is all I have to go on. The label on the trailer side is long faded away. Finally, my axiles are 33" apart (on centers) the spacing between the tires has been reduced 1/2" to 1.5" spacing.I can no longer use my wheel locks when parked. Dave, Tucson, Az.
A set of ribs or R250s will serve you well! Chris
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Chris
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02/09/12 07:35pm |
Fifth-Wheels
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RE: Revived Trailer Tire Thread (formerly on the 5th Wheel Forum
Let me see if I understand correctly.
You say that an ST tire needs a 15% reserve and should not be loaded beyond 85% of sidewall capacity. Also, you indicate that the LT tire can be used at 100% of it's sidewall capacity.
If this is true, then a lot of manufacturers of RV's are doing their customers a disservice by putting underrated tires on their vehicles. One that comes to mind is JAYCO that still installs 16" load range "D" ST tires with a 3000# load capacity on rigs with 6K axles. Don't believe me? Go to your nearest dealer and take a look.
Keith
Or most Montana's with GAWR OF 6750 and tires rated to 3420. Do the math 90 full pounds of extra capacity per axle. Chris
The RV show at the Jacksonville, FL Equestrian Center opened today. It was also half price day for seniors so we drove out for a look see.
Here is one that confirms none of the major heavy fiver trailer manufacturer's give a hoot about reserve load capacity in their OE tire selection.
Here is a picture of a vehicle tire placard. It’s self explanatory.
Tire Placard
The nice clean tires were easy to read. Goodyear Marathons
rated at 3420# at 80 psi. Isn’t that just GREAT?
FastEagle
FastEagle how do we get consumers and manufacturers to wake up?
60 minutes seems to gotten Congress attention on insider trading! Anyone know someone on 60 minutes staff.
I can see it now Barry our new buddy on 60 minutes!!! Chris
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Chris
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02/09/12 07:24pm |
Tech Issues
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RE: Revived Trailer Tire Thread (formerly on the 5th Wheel Forum
OK . . . I think I've been a little slow the past few days. It's the K factor!.......So if I got that right . . . I can take it to the next level. The service conditions for trailers are not understood correctly so the K factor for ST tires is wrong.......
That is an argueable point. It could also be argued that far too many trailers overload the tire. The situation is terribly unclear.
.......The trend in the industry has been to go to bigger and bigger units with more gadgets in them. Perhaps the TRA needs to revisit the K factor......
or perhaps the trailer industry needs to size the tires to cover those differences. After all that's what car manufacturers do.
But, again, the situation is terribly unclear.
I have been saying for a number of years to not leave the dealers lot on inferior tires. No one else seems to be assuring that trailers have decent tires, so buyers should be looking at more than the glitter and bling.
However intended use plays into it. If you are going 10 miles to the lake and back once a year then minimal tires might be OK. If one wants to see America, then you need good tires for a safe and comfortable trip.
Chris
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Chris
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02/09/12 06:04pm |
Tech Issues
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RE: Revived Trailer Tire Thread (formerly on the 5th Wheel Forum
Dear Capriracer:
I'm interested in an apparently widely held presumption in this and other thread discussions that ST tires fail at a greater rate than LT tires (when installed on trailers).
You seem uniquely situated to provide actual statistics supportive (or not) of this belief.
Can you do so, and give links to any studies and/or statistical analyses regarding this correct/incorrect conclusion?
(All other things including proper/improper inflation being factored in, of course.)
Thanks!
First, tire failure rates, warranty data, and the like are closely guarded secrets for the tire manufacturer. So you won't find such statistics published anywhere. As you point out, I am in a positon where some of this data is known quite precisely - and unfortunately, I can't reveal it.
But every once in a while there's an opportunity to glimpse at what the real numbers are. For ST type tires, it's clear that these are used 100% on trailers. If we assume that the vast majority of these are on trailers that are near or over the load limits of the tires, then we have a series of conditions that define a usage.
The next part of the problem deals with LT tires - which MIGHT be built exactly the same way as ST tires - and at this point, I'm going to digress and talk about weight differences between comparable ST and LT tires.
If I start with the assumption that ST's and LT's are essentially the same, can I explain the differences in weight? (For the moment, I am excluding steel body ply LT tires and confining this to polyester plies / steel belt constructions).
I did a quick look between a Goodyear Marathon ST235/80R16 at 34# and a diameter of 30.7" and a tread depth of 10/32nds and a Goodyear Wrangler SRA in a slightly larger size LT235/85R16 at 43# (26% more) with a tread depth of 14/32nds (40% more), and an overal diameter of 31.7" (3% more) and I do an estimate of the difference in tread width (LT being 25% wider), I think it is easy to see that the actual differnce in the casing is pretty small.
So if I assume that LT tires are basically the same construction (and I've demonstarted this is a pretty good assumption), then the failure rates ought to be about the same.
But I am left with the fact that not only do I not know the population of LT tires used in trailer service, but I also don't know if LT's are used in EXACTLY the same way - after all, there is a difference in what sidewall says about the max load. Did that result in a change in loading?
But there are 2 factors that might be impacting this: The first is that LT tires would be built in the more modern factories on the more up to date equipment, utilizing the most up to date constructs.
The second is that once an end user has a tire failure on an ST tire, he would try to remedy that by throwing the kitchen sink at the problem. I'm pretty sure there aren't any A-B-A type of comparisons going on and I'm also pretty sure that there are mulitple changes made that cloud the issue.
The fact that there is so little overlap between ST tires and LT tires (size for size) further complicates the issue. For example, I was asked if replacing an ST235/80R16 with an LT245/75R16 was the right way to go - as this would be going the wrong direction if we take the published max loads at face value.
If I go back to the formula used to calculate the max loads - and make the assumption that the construction is basically the same and the only difference is the K factor that is accounting for difference in service conditions, then the LT245/75R16 has a larger (better) number. I point this out as a complicating factor in trying to sort out.
But I will tell you that I see an awful lot of LT tires used in trailer service with failures - and there is one more item that I can't reveal so you'll have to trust me on this - when aI do apples to apples comparisons, I don't see a difference.
But let me state it this way: I don't see that there is any harm in replacing ST tires with comparable sized LT tires, and there is likely a benefit. BUT there is nothing inherent in the design of ST tires that makes them so prone to failure. The apparent difference could easily disappear.
CapriRacer, if one goes to a tire store and handles a typical 35 pounder ST tire in the ST235/80R16E (you choose the flavor of the month) and then a LT235/85R16E (try a BFG Commercial TA) the statement that they are very similar seems to fade away. Then if one compares the R250 or Rib the difference is even greater yet!
The "what works group" is having pretty results with these three tires along with several others. Poster after poster shows up here claiming that tire failures ended with the replacement of ST tires with LT tires that can handle the load. The LT that seems to have gotten the bad rap was the Uniroyal HT/H that was used on many HHII that where to heavy for the tires on one or more wheel positions. The GY LT G614 also does not have a perfect rep. Again over weight seems to be the issue along with 2006-7 production issues!
It is important to know what weight is on each wheel position when replacing tires.
Chris
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Chris
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02/09/12 08:06am |
Tech Issues
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RE: Revived Trailer Tire Thread (formerly on the 5th Wheel Forum
CapriRacer,
There is a lot of credence placed on the fact that similar LT tires weigh much more than a like sized ST tire. Because of the extra weight the supporters beleive it has to be stronger and support more load capacity than advertised. I’ve tried on numerous occasions to logically explain how that happens but because I lack the credentials you possess my logical postings are sternly argued down.
The most popular argument comes from those that support the use of the LT235/85R16E tire with an all steel casing, extra sidewall materials for protection from curb scuffing, an extra steel belt and the ability to be retreaded. It’s a mileage tire and weighs 55.8#.
In the ST corner comes the ST235/85R16E. It tops the scales at 39.5# and has a shallower tread - it’s not a mileage tire or retreadable - it’s basic construction is a couple of steel belts with - maybe - some nylon caps and polyester sidewall cording. Surely the density of the rubber materials are much lower on the durometer scale than that of the retreadable mileage tire.
From the formal instruction I received on aircraft tires it was stressed that a tire’s strength is derived from it’s basic construction, not the tread or other frills.
I know others along with me would like to have your professional opinion.
FastEagle
Why don't you ask CapriRacer what he thinks about the all steel ply/belt 17.5 commercial tire that you have choosen to install in the spring. Maybe he can talk about the benifits of getting off of 16" rims and their short comings on larger trailers. Given that 215/75R17.5 tires in load range H or J are becoming the de facto super solution, it would be great to hear his cut on them. Is a there need to worry about the damage a failed steel carcass tire will do etc? Would one air them according to load tables? Seems like you have not been clear on history and future direction. Carpi Diem
Chris
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Chris
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02/09/12 06:02am |
Tech Issues
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RE: Revived Trailer Tire Thread (formerly on the 5th Wheel Forum
FE where is the Max load x,xxx at xx lbs. Tire in picture is "talking" about the wheel to mount it on, not its limits!
Most other ST rated above 3420 lbs require more than 80 lbs inflation. Just shows to go you that industry standards for ST tires do not exist or vary a lot. Chris
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Chris
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02/08/12 09:30pm |
Tech Issues
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RE: 5th Wheel Tires
My 5th wheel weight "wet" (fully loaded) is predicted to be 12,720 lbs. The hitch weight is 1600 pounds. The tires I had installed are the largest, strongest LT tires I could mount that were affordable. (3042 pounds each). Goodyear has the same size tire with a sidewall rating of G (3750 pounds each. $$$$$$$
So the 12,720 pounds includes the 1600 pin weight? And you 11,120 on the axles? Chris
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Chris
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02/08/12 09:20pm |
Fifth-Wheels
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RE: Revived Trailer Tire Thread (formerly on the 5th Wheel Forum
Capriracer, you talked about we consumers banding together to share info on what works! We have been trying to do that here for a good number of years! However tire threads often get closed when posters show up with a stack of documents and start saying "you can not do that"! And some flat do not like the brand/model that works better than any other. That leads to more back and forth that gets threads closed. SAD!
In reading your posts over the last week it does not seem to be as black and white as they claim!
So keep the info flowing.
Thanks - Chris
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Chris
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02/08/12 05:14pm |
Tech Issues
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RE: Revived Trailer Tire Thread (formerly on the 5th Wheel Forum
Yesterday while visiting a local RV trailer dealership to shop in their well stocked store we saw an attractive - full body paint - fiver on display and on our way back to our truck decided to check it out. Those of you that know my writings wont be surprised to know that my first stop was at the vehicle labeling information. Then I took a look at the installed tires.
Here is an example of what perspective RV trailer buyers (experienced or first time) will find on a new trailers labeling. After reading the tire and vehicle weight information depicted on the placards - referenced below I inspected the tires. They were in fact ST235/80R16E rated at 3520# at 80 psi. The 7Y manufacturers code indicates they are Kenda tires made in China.
This is a large trailer with enough extra storage compartments to carry well over the maximum load described on the labeling. It is more than a common occurrence to find similar UNDER RATED tires on just about any RV trailer manufacturers products. I’m not singling out a brand here, it just happened to be there.
Down the road the buyer has an above average chance of having serious tire problems with the configuration the manufactured has provided and the dealer has passed on.
There are a number of problems that will confront the new owner of such an equipped trailer. Not obvious but factual is compliance with the 7000# axle requirement. There are other ST tires with the exact size description that will only list 3420# of load capacity on their sidewalls. That could easily be overlooked by an inexperienced installer and surely by the vehicle owner. Carrying a rim/tire assembly from the above trailer into so-and-sos tire shop and asking for a LT tire replacement could result in getting a LT235/85R16E replacement - “it’s a LRE tire”.
Those are just a few examples that confront RV trailer owners seeking replacement tires for their failed OE tires.
Tire Placard Info
If this thread or any like it about tires for the RV trailer needs a direction to follow it really needs to present the reader with acceptable and safe solutions. It’s too late to point fingers when your setting on the side of the road with a couple of failed trailer tires. I’ve had a lot of experience doing just that and it’s not fun, but it will help keep you fit.
By the way, I still use ST tires. I could never determine any of my failures were caused by defective tires and once I got above 12% with my actual load capacity reserves my failures quit. I’ve been using the same name brand - from china - since 2006 and I’m on a second set.
FastEagle
If you would please unblock PM's, I would like to reply to this post offline. Chris
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Chris
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02/08/12 11:17am |
Tech Issues
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RE: Permanent rubber hose for LPG inside RV?
Flex copper pipe similar to my furnace at home. Chris
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Chris
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02/08/12 09:17am |
Tech Issues
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RE: Revived Trailer Tire Thread (formerly on the 5th Wheel Forum
So if you remember my comment about failure rates between ST's and LT's used in trailer service, what I am referring to is WHEN the constructions were similar back in the day. That is likely not the case today (I can't sure because I am only aware of what is happening in my backyard and other backyards exist that I can't look into.)
I think that last time Goodyear changed anything in the construction of the Marathon was in the late 90's during the silent recall when they added the Circle S behind the Marathon on the sidewall, as an indicator of the new construction.
These are a type of tire that has not kept up with their current use! Goodyear will do a run of them in a plant that has open capacity about once a year. That is why they have bounced production back and forth to and from china. Goodyear claimed it had nothing to do with quality!!
Taking a tire that was designed for utility trailers and running cross country on a heavy/tall 5th wheel seems like a mistake. Add trailer manufactures that are building to the max rating of the tire and we see the results here quite often. Few trailers weigh the same left to right, so even the max is exceeded on one side or the other. So we have a problem just weighting(pun intended "waiting") to happen!
Chris
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Chris
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02/08/12 08:43am |
Tech Issues
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RE: Revived Trailer Tire Thread (formerly on the 5th Wheel Forum
Well I looked at my new Bridgestone LT235/85R16 LRE Duravis R250's and the max load info, and they list max press. The Michelin LTX M/S on the truck just say max load. I have one Michelin XPS Rib still as a spare and I could look at it, however I think it says just max load. Is max pressure assumed in those that just say max load????
I would also note the the R250 has one Nylon ply that the Ribs do not have, so you can not call it an all steel ply tire like the Rib. Chris
http://i269.photobucket.com/albums/jj53/snoking1127/DSCF1394.jpg WIDTH=640
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Chris
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02/08/12 08:29am |
Tech Issues
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RE: trailer tire blowout damage. need repair info
If those are GY Marathon's file a claim with them. Another ST bits its owner! Chris
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Chris
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02/08/12 06:04am |
Fifth-Wheels
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RE: 5th Wheel Tires
A 13000 lb wet trailer ?? With 12168 lbs of capacity tires !!! Keep them pumped to the max sidewall pressure 24/7.
Its after the fact now but is the 13000 lb a estimate or actual scaled axle weight ??
Maybe he is including pin weight!!! Chris
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Chris
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02/08/12 06:02am |
Fifth-Wheels
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RE: Trailer Tire Rotation
I am not sure moving radials on a trailer from one side to the other and reversing the rotation is a good idea. On cars and trucks they usually move tires straight forward and cross the fronts to the rear. TRAILER tires that are not tested to LT standards are not the best tires in town so I would not mess with them!
In the early days of radial tires we always only left them on the same side of trucks and cars just swapping front to back, as there was a worry about the tires taking a set! Given that ST radial tires are more like the original radials than todays modern radial I would just leave them and get new ones every three years. Chris
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Chris
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02/07/12 09:20pm |
Tech Issues
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RE: Battery Monitor Shunt Installation Plus Battery Disconnect
I should have added that the inverter is 2000W and can draw up to 166A steady state, not that I push those limits. It also regularly charges at 100A so I need a heavy duty disconnect switch. Perhaps the Blue Sea in the above link.
Unfortunately the design of this rig does not allow the the charger/inverter to be close to the batteries. I estimate that the negative lead is 20' and the positive lead 30' so anything that I introduce in the circuit has to be the lowest possible resistance.
Shame on HR, longer runs should have been on AC side of inverter. Props to you for wanting to manage you batteries. Send me a PM with an email address and I will send you a nifty amp hour spread sheet that I created.
You should get a 500 amp disconnect switch. Chris
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Chris
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02/07/12 08:44pm |
Tech Issues
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RE: 5th Wheel Tires
Well you should watch them closely and think about replacing at year 6 to 8, depending how old they were when you installed them. I took mine off after 6.5 years and 40k+ miles. Sold them on CL for 200.00. 3 were 7.5 years old and one 8.5 according to the dot codes (that will not happen again). 8.5 year old one was starting to get small cracks.
Installed Bridgestone Duravis R250's for the next 6 to 8 years. BTW the Ribs hardly ever needed air added!
Chris
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Chris
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02/07/12 08:11pm |
Fifth-Wheels
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RE: 245/75/R16 or 235/85/R16?
Either are good. If you need the shorter 245's because of axle space, then get them. Otherwise 235's are great. Chris
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Chris
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02/07/12 06:17pm |
Fifth-Wheels
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RE: Revived Trailer Tire Thread (formerly on the 5th Wheel Forum
When you have time, maybe you can address the difference in testing standard between ST and LT tires. Also maybe write a little about the much lighter weight ST tires getting higher ratings than LT tires. Maybe the answers is the same for both questions? Chris
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Chris
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02/07/12 05:49pm |
Tech Issues
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RE: Revived Trailer Tire Thread (formerly on the 5th Wheel Forum
I thought the GY Marathon 10lb pressure increase was to exceed the 65mph limit, but not to exceed the max pressure on sidewall. That is that it is applied to pressure/load chart. ??? Chris
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Chris
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02/07/12 05:37pm |
Tech Issues
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