ST orLT tires?? - Page 2 - Montana Owners Club

HamRad · 10-29-2009, 05:43 AM

Quote:

quote:Originally posted by richfaa

becoming educated on all the aspects of weight concerning the truck and camper gives one a bunch of things to become concerned about that you were not concerned about before such as tire load ratings for one. Gives a new meaning to the saying " ignorance is bliss" Just a few weeks ago I was blissfully careening around the country with not a worry in the world...then..I got weighed. [:O]

Rich,
You are so right! I was so much happier before I read about all the possible things that need to be checked before one drags the Monty out on the road! Guess I'll just have to stop reading!

Let's hear it for "ignorance"! Just kidding of course. The information we've gained here is absolutely invaluable and has saved us from some potential terrible consequences.

Keep the information coming!

Thanks,
Dennis

8e3k0 · 10-29-2009, 09:04 AM

We are running good quality LT tires that are "E" rated on our 3400RL right from the time the unit was new in May of 09. We removed the Good Year Marathons ST tires after about 2500 miles and this included the trip from the factory to the North West. Quite interesting that ST tires will state "for trailer use only" and not to exceed 65 mph. The LT tires are for trucks and SUVs and can have speed ratings of 90 mph which to me supports a higher quality that does not allow any heat to develope with load and speed over time as long as air pressure specs are attained to. We must remember that LT tires have to meet a more rigid safety spec than ST tires as human safety comes into play. Our LTs on our Monty run cool and very similar to the TVs tires. To me that's important as heat over time distorts, rubber, nylon, metal and this is where tires will fail if not constructed well and maintained properly. My vote is for LT tires even if they are a few lbs under the rating of ST tires.

richfaa · 10-29-2009, 09:57 AM

We are on our 2nd set of LT tires having destroyed our first set in our U bolt disaster. By our TPMS we observed that the LT tires ran a bit hotter than the St's determined by the higher pressure readings on the LT's.....not a lot..but higher just the same//

wersqu · 10-29-2009, 10:07 AM

Ours came with LT tires on it and replaced at the 5 year mark with LT's again. Never had a problem yet.....knock on wood.

ols1932 · 10-29-2009, 12:12 PM

My advice without any quibbling is to go with what the experts are saying.

Orv

rgreynolds · 10-31-2009, 08:01 AM

We've been full-timing in our new '08 3400RL now for 18 months. I've gone through all 5 of the Goodyear Marathon tires that came on it. They were rated E and are a 10 ply tire. Found out that the "ST" stands for "Special Trailer" and is suppose to stand up to those tight turns you make with a 5th wheel where it twists the inside tires. Four of the tires all had belt separation and the one I'm using as a spare has a side bulge. My neighbor in this campground has "G" rated Goodyear tires on his 5th wheel. He's a full timer and his tires are 10 years old and look like they'll go forever. A lot more expensive that the E rated tire, but overall, it may be worth it. Bob

richfaa · 10-31-2009, 09:41 AM

The primary consideration is the tire weight load factor. There are quality E rated tires with the proper load factor. With 7K axles theoretically one needs a tire with a load factor of 3500lbs. The key word is "quality". ST tires normally have a higher load factor than Lt's but the present quality is suspect. We are running a good brand E rated tire but are over the tire weight load factor. Our next set of tires will be a quality brand with the proper load factor.... I agree with Orv "My advice without any quibbling is to go with what the experts are saying.'

Orv

blarkman · 10-31-2009, 10:15 AM

What got me started on this post was when I read Richfa's post on having each wheel weighed and the difference between the ST and the LT tire capicity. If there is 500# difference per wheel this come out to 2000# or one ton load less. Does this mean that if you have 7000 axles and go to LT tire you have to reduce what you can carry. AS the two axles would be 14000 and now the LT tires would be 12000. Does this make sense?
bob

Tom S. · 10-31-2009, 10:55 AM

Yes it does make sense and your question is why it is important to have your trailer weighed when it's loaded. Ideally, weighing by the wheel, next best would be weighing by the axle, and last (but better than nothing) weighing the total trailer. I need to note that it should be weighed when hooked up to the tow vehicle. Once you've done that, you can answer your own question. If it weighs too much for the axles, you either need to lighten it or replace the axles. Same thing applies for the tires. In other words, both the axles and the tires (separate of each other) must meet the real world weight of your trailer if you want to be safe. Do not assume that because so and so's trailer weighed XXXX lbs that yours does too.

richfaa · 11-01-2009, 07:56 AM

Weighing can be a eye opener... The General LT 235/85R16C load range E tires that we had to put on after our U bolt failure are rated at 3086 lbs at 83psi or 6172 per axle or axle load of 12,344lbs... This is from the RVSEF weighing record from the fall rally
Right tires front 3125 rear 3175 Left tires front 3200 rear 3425 axles front 6325 rear 6600.. or total axle load of 12,925lbs Not a pretty picture.. That is WITH the IS suspension giving us a 7K axle rating...BUT.. we are OVER in all tire ratings. Those were he only reading in the red for the RVSEF weigh in taking into account the 7K axle rating of the IS suspension. (all bets are off as far as Keystone is concerned)

At the risk of being called the weight police which I always have been..get your rig weighed properly..At least you will know for sure where you stand. If over in any area the decision on what to do is still yours.. Remember there ARE quality LT E rated tres with the proper load ratings.

Tom S. · 11-01-2009, 08:37 AM

Rich, refresh my memory - did you have disc brakes installed with your I.S.?

richfaa · 11-01-2009, 09:21 AM

No.. We will do that next year at the rally..Got to save up the bucks..

exav8tr · 11-01-2009, 10:26 AM

Quote:

quote:Originally posted by Tom S.

Rich, refresh my memory - did you have disc brakes installed with your I.S.?

Tom, I had the full install including the Kodiak Disc brakes and 8 lug Dexter Nevr Lube hubs with 9/16in lugs. Love the system...

Phil

Tom S. · 11-01-2009, 10:47 AM

Thanks Phil. Did you happen to watch them do it? The only thing I'm not sure about is the hydraulic system. It's getting too late in the year here in the frozen north to do the conversion, but I'll be thinking about it all winter.

exav8tr · 11-01-2009, 01:40 PM

I didn't watch but they installed a Carlisle Hydrastar hydraulic brake actuator in the front compartment near the battery. The only problem was that the Carlisle would not operate off of my built-in IBC so they installed a Prodigy. Something about difference in voltage. This was discussed with me ahead of time and I was OK with the Prodigy as that was what I was used to.

You may also like: