110 psi rim upgrade?

I'm replacing the 2004 tires (due to age) on our 36' 10" Challenger 5th wheel. I can get a good price on LT 235 85R 16 Multimile Solid Tracks made by Cooper. I can go from my current load range "E" to a "G" at about $20 more per tire. Problem is current rims are rated for 80 PSI and the "G" is 110 PSI rated. Keystone said "E" is sufficient. The specs stamped on current rim is "16x6K Trailer use only, Made in USA." They are 8 bolt. The person that wants to sell me the tires is an experienced Body/Collusion shop owner and not really in the tire business but knows what he's talking about. He's pretty sure I can stick with the old rims and a Keystone dealer stated the same. Still I'm afraid if somebody put 110 PSI in the tire I might have a problem or they could have. Is there a way to find what rim ratings mean or how to read them like on tires? Any ideas are appreciated. Thanks all.

Your friend may be just telling you what you want to hear just to sell you those tires. You said he was a body man....not a tire expert. I'd stay with a manufacturer rated tire and wheel combo and stay away from a 110 psi rated tire unless you want to upgrade your rims. Also with that much tire pres your trailer will ride a lot rougher.

The first question is whether you need LR G tires or not. If an "E" has sufficient load capacity, there is no point in changing to an F or G rated tire. In my opinion, "sufficient" load capacity is about 10% more than the maximum expected tire load. You need to know the trailer GVWR, or better yet, the individual axle weight ratings, to compute how much load the tire must carry.

If an F or G tire is warranted for the load, then the rim question comes into play. There should be a tire inflation table for those Coopers that tells how much pressure is needed for a given carrying capacity.  You don't have to inflate to the maximum psi on the sidewall unless you need the maximum load capacity, which seems unlikely on a G rated tire.  However, a G tire at at 80 psi may not carry any more weight than an E tire at 80 psi.  So it all comes back top the weight on the tire again. If you need the extra load capacity, you probably need ti upgrade the rims too. The question is, do you need the extra capacity?

The pressure rating on the rims is just what it says - the maximum safe psi the rims can handle. Some body could overinflate the E tires too, but the risk may be greater with a G tire because of the sidewall pressure may entice a novice tech to run the pressure up to 110 psi.

The bottom line is that you need to do some arithmetic with the trailer weight/GVWR and figure out if those G tires are going to do you any good or not.

Sorry for not getting back sooner. A friend of mine that is in Collision repair business and does tires has gotten me a good price on a Cordovan Solid Trac  commercial trailer tire  (I goofed and made a new post under 5th wheels--again sorry.) Anyway, he's checked with his friends and experts in the business and they highly recommended the tire. I can't afford Michelins or Bridgestones but can't afford to hurt or kill somebody either. Told them this and am assured even though the tire is made in China that it is safer than using E rated  tires. Somewhere I saw or was told that the Good Year Chinese tires were a design defect and was corrected. Not sure.  Now even Cooper is making tires in China. Seems there should be a forum just for tire issues and information.
Thanks for all the help
Marty

I wouldn't change to a G tire. As I understand it, the G tire will hold more air and is much sturdier than the E tire. That will mean a rougher ride for your 5th wheel. I know about rough rides. On my recent trip accross the US and up into Canada I tore up 2 of the brand new tires on my 2009 5er. In my opinion, the tires were cheap foreign made and I was glad to get rid of them. I had all 4 tires changed for 4 Goodyear Marathon tires, also load range E. The big difference I think was the Goodyears are 10 ply while the old ones were not. Well, the resulting ride across Trans Canada 1, a boring flat road, was my dinnette tipped over and my desk drawer opened twice. I can only assume that the ride was rougher with the 10 ply tires. As I only need about 11,000 lbs for the axles, and the tires are each rated for 3,400 lbs at 80 psi, I will run them at less pressure to soften the ride.....maybe at 75.

Bob

Thanks for the reply. I run about 80 psi in my current E rated tires. I'm going to try the 14 ply G's as I like the extra plies. Will still run around 80-90 psi. Don't like the idea of them being Chinese but have been assured this won't be a problem. Time will tell. I'm working on getting my wheel weights. Again thanks.

Price wins every time right??>>>Dan

In todays economy and if you don't have it-you don't have it situations you're probaby right.

Well, I was going to get "G" rated tires made in china and use my current rims. By the time I decided i would risk Chinese tires and my rims, they were out of stock all over the west. But it just so happened that the original Power King I wanted from MultiMile which was out of stock were back in stock.
So I now have a set of LT 235/85R16 10 ply load range "E" Radial Highway tires from TBC. I have a 2005 Challenger 5th wheel and found after we removed a tire that the rims are labeled inside for 110 PSI. Don't have a clue why it's hidden, except people like me would go buy a new 110 PSI rated rim if they were going to  a 14 ply tire. I'll try to post if they fail or wear bad.
Thanks for all the help.

Whoa!  Slow down and think a little.  Don't let people scare you out of thinking for yourself.  It's not about brands and prices.  It's about tire capability to carry the weight.  Take your rig to a scale and weigh it without the truck on the scale.  Then divide the total weight by the number of tires on the trailer.  When you know the load on each tire, go to the tire manufacturer's website and find the table that tells you how much air pressure you need in the tires to support the weight and wear properly.  This air pressure will likely be LESS than the maximum pressure stamped on the side of the tire.  If you fill the tire to the max pressure on the tire sidewall, the tires will likely wear unevenly and give you a stiff ride, causing things to fly around inside your rig. 

About tires and what to buy.  There are many tires that meet minimum specs for any load range.  This does not tell you what the best tire is.  To know that, you will want to know which of the tires you are considering is the heaviest.  A heavy E-range 16 inch tire will weigh as much as 55 to 60 lb.  A lightweight tire might weigh 38-40 lbs.  Much of this additional weight is in the sidewall of the tire.  A heavy tire will flex less than a light tire.  Less flexing means it runs cooler.  That means fewer blowouts.  All you need is one delaminated tread to come off a tire to find out how much destruction it can do to your rig.  Learning all this the hard way has convinced me that the most expensive heavy tire is likely the cheapest tire when you count the destruction that can happen when using cheap tires.  Sure, the higher-rated G tires will be heavier and tougher than an E rated tire, but the pressure you put in one would likely be very close to the same as in an E tire.  This is because the tire pressure required is dependent more on the weight the tire carries than on the type of tire.

Well, I've received lots of different advice on tires and unfortunately I can not afford the heavier tires and rims nor Michelin Ribs. I do feel safer with the month old "E" rated tires made in Ohio than I did with my old tires made in 2004. Of course Keystone who makes the trailer and put the info plates on it said the tire size recommended for my particular trailer are more than sufficient. I was looking at tires on new trailers of the same size and heavier in CW and the new ones have smaller "E" rated tires on them. I have weighed all my axles, truck by itself and 5th wheel by itself and calculate that I still have 2000 lbs to meet max weight, however I'm trying to shed weight.
I think that with all the tire issues with both motor homes and trailers, that there should be a category on the Forum for "Tire Issues" just like Tech or a sub category under Tech. This will always be a controversial subject and I thank all for their advice.

Well Marty, you are right on target with your assessment on tire selection and the controversy it creates on this and most other like forums.

Keystone has always had problems with tire selection for their RV trailers. They are so obviously driven by the bottom line ($). All of their fifth wheel trailers in your weight range (6000# axles) for production years 2005 and 2006 were fitted with the LT235/85R16 LRE tire. At a basic 3042# at 80 psi it barely meets the minimum requirements for the axles. Like the ST tire there were many failures so in 2007 Keystone upgraded to the ST235/80R16 LRE tire. At a basic 3420# at 80 psi it provided more load carrying capability but has a speed restriction that is critical to it?s performance.

What it all boils down to, for you, is the ability to stay with the recommended LT tire or go to the ST tire. All of which require the 80 psi capacity of your wheels.

My Keystone RV trailer is a 2003 issue. It came with ST235/80R16 LRD tires. Like yours, my trailer is 37? 10?. I blew three of those LRD USA made Marathons in less than a year. I know use LRE 3520# ST tires with no problems.

Keystone does not evolve well. The same 3520# tires I use on my 6000# axles are OEM on many 2010 Keystone 7000# axles.

Do you remember when you rented a U-Haul trailer and it was printed all over the trailer, MAX PSEED 45 MPH. Yeah, right!

FastEagle

http://keystone-challenger.com/?page=specs&year=2005

I do remember them and NEVER went over 45. Yeah right. I was young and foolish then. Now I'm old and foolish. Wonder if they still have those signs on them? Still about the tires, hopefully these tires will last me until 2016 unless I have to up grade before then. Then I'll go through this all over again and hope I get a safe tire.