View Full Version : Getting Weighed (your RV, that is)

04-20-2007, 04:26 PM
As the latest newsletter mentioned, we will be weighing RV's before, during & after the rally. If you're interested in getting weighed after you check in & before you get set up in your site, please let us know by email or phone which day you are arriving & an approximate arrival time.

We're in Branson now so if you're arriving *really* early, we can accomodate you now. :lol:

Stacey Frank
Weigh-It, Portable RV Scales

04-20-2007, 09:39 PM
If you have not had your DT Suite weighed, Stacey does an excellent job of it. Tire pressure is checked, both on the TV and 5er.

In the case of RVs and tow vehicles, ignorance is [/b]NOT bliss!

There is a Landmark here at Butterfield RV Resort in Benson AZ with pretty serious damage on BOTH sides from blowouts!!

04-22-2007, 10:28 AM
Thanks for the kind words, John. We try to provide a service that people need. In a lot of cases, it's *after* the tires fail that people are looking for answers. We find many times the answer is: tire air pressure and weight.

04-26-2007, 06:54 AM
I'm a new owner of a 2004 K3.
Yesterday on "my first pull" I headed to the CAT scale.
The trailer is EMPTY, nothing but a a full load sail-boat fuel,
it tipped the scales at 11,860 lbs on axles, and 14,240 total.

I ran my GY G614's at 95psi, and in the 85* heat of the day @ 62-65mph they climbed to 104psi.

I think I'm going to need more tire....like those H-rated 17.5 units.


04-26-2007, 07:33 AM
I don't know what a K3 is, but the pressure increase of your tires is about right. I would start them at 110 psi though. I have a pressure pro system which continuously monitors the tire pressure. I start my 17.5 tires at 125 psi and after a few miles they are at 142 to 144 psi.

04-26-2007, 09:17 AM
I agree with Dave, I have been told by several guys in the know on these tires that you better keep the pressure at 110# as recommended by the manufacturer, regardless of the load, or you are increasing your chances of a failure.

I currently have a tire at the Good Year store to replace one of mine, which is showing something that may be the beginning of a slight tread separation from the carcass. They are not sure if that is what it is but are going to replace it.

I have maintained 110# for the most part and have maybe 5k miles on the tires.

Texas Tire Terminal has a 17.5" tire and steel wheel ($175 for tire - $125 for wheel) available which will work on the existing hubs on the Dexter axles which our MS has with the 9/16" studs; thus no need to change out hubs and/or studs (depending on whether you have 7000# or 8000# axles) which is required if changing to the Alcoa wheel since they are hub piloted and require 5/8" studs.

Granted you would then need to purchase a nice stainless steel wheel cover, but they are readily available and still makes your cash outlay near $1,000 less than Alcoa wheels with Good Year tires. Based on earlier research which I did and passed along on this forum.

http://www.herculestire.com/hercules/pdfsCommercial/07_herc_s208_s209.pdf the S-209 215/75R17.5 H rated 16 ply


04-28-2007, 07:19 PM
Sorry about my typo in my earlier post.
I have a 2004 TK3, not a K3. :lol:

Anyway, this tire inflation topic is getting perplexing.
The GY tire inflation guide says I should be"OK" with the load I was running, to have only 75psi.

Others say from experience with their PRESSURE PROS that 110psi is what is required all the time.

What should a guy do????


04-28-2007, 09:36 PM
Diesel Gypsy:

This tire thing has bitten a few of us multiple times and as per suggestions from a number of tire dealers I've talked to (spending entirely *pun* too much time in their shops) and most recently Tire Tech over on the Escapee's forum they've all mentioned the same thing: lower pressures means more sidewall flexing, more sidewall flexing means more heat, more heat means likelyhood of tread separation is increased.

Now the hard part is to discipline ourselves to run at or closer to the sidewall stated cold inflation figures and also compensate for hotter ambient temp days by running slower and stopping more frequently.

I get the feeling that simply running at the max cold pressure and blazing down the highway with one of our tires overloaded (easily done on the kitchen side) will simply lessen the chance of tread separation but increase the chance of blowout from overpressure. JMHO.

My next step in the fight to lessen the odds is to have my trailer weighed by Stacy at the upcoming rally to determine my exact individual tire weights while carrying our typical winter snowbird load of "stuff".

04-29-2007, 08:25 AM
There is another reason to run the trailer tires at full cold pressure. It helps keep the sidewalls stiff for tight cornering situations where the tires get significant side loads and scuffing.

04-29-2007, 08:51 AM
I sort of agree with you about the tire flexing and OK on getting the unit weighed at the rally. OK now what will you do after you find out what the weight on each tire is ? Will you use the tire manufacturers load inflation tables to determine the cold inflation pressures? Or pump em up to 110 pounds because thats the max load carrying capacity as printed on the tire?

I have been running Michelin XPS load range "E" tires on my Dodge dually and an 1989, 40 ft LondonAire with no problems. I have been inflating those tires to what Michelin recommends in their load inflation tables. I have been getting around 80,000 miles out of a set on my Pickup. Don't know about mileage on the trailer tires as I haven't kept track on that. One is dated in the middle of 2000 and the other three are dated early 2004.

I recently sold the LondonAire and bought an 04 MS 36TK3 with GY 614 "G" rated tires on it. Had the MS weighed on a set of Cat scales and again by a DOT officer who weighed each tire with a set of portable scales. Looking at the GY load inflation tables, the tires should be inflated to 90 pounds on the dinette side and 95 pounds on the kitchen side. This is what I have inflated them to. I will be going from Pensacola to the SKP, LOW up in Bowling green Ky next month. So I guess we will see what happens on that trip with those inflations.

So what am I driving at with this long post? I'm trying to say I think the manufacturers know what the proper inflation pressures are, for what weights are being carried by each tire. I have followed them with good results on the Michelin tires and am hoping for the same with the GoodYears.

Would appreciate your views.
Best regards

04-29-2007, 09:56 AM

I tentatively agree with everything you have said BUT, your LondonAire & truck experience using inflation tables was gathered with Michilin's and your 40' LondonAire probably had triple axles? If so, your load was spread over 6 tires, not four.

It isn't my intent to denigrate a product but my previous experience has been gathered using tires of one manufacturer (other than Michilin) and following it's load/inflation tables. My previous trailer weighed under it's GVWR of 13,780 by a full 1,000lbs, ran 2 - 6000# Dexter axles and came equipped with 16" - E tires and over the course of 2 years of usage with those tires, I had 3 incidents of tire shredding & blowouts. I subsequently (upon recommendation from a tire dealer) changed to tires with a less agressive tread pattern from Hancook with same rating and in 2 more years of same distance/roads/loading/inflation had no further problems.

Since our purchase of our M/S 38 and while admittedly using the inflation tables to air up my 17.5's to a safe-for-weighed-load of 115psi using the mfgr's inflation tables and allowing for a margin at that, I have shed the entire tread from one that remained inflated at the 115psi and a tire from the opposite side has developed extreme cupping of tread. The alignment of my suspension has been checked at Trailair's service facitlity.

When the trailer was at Trailair's factory I again attempted to have the tires balanced only to be told "again" that 2 of them would not balance satisfactorily (out of round) and guess which 2 I've had problems with. I have since replaced the badly cupped tire (it resembled the shape of a Canadian Nickle) and upon attempting to get some good faith adjustment from THAT mfgr, was simply told, "nope, your tires were mfgr'd in '05'!"

I have checked the wheel balance while sans tire and it is fine.

I have used an I/R gun since early 03 and have used Pressure-Pro monitoring system since early '06'. Travelling interstates at 65 mph is our practice and it is my belief; all things being equal, these tires should be able to withstand usage under the conditions I view as normal and within parameters of design.

I have purchased one more of them $402.00 Tx included Canadian, :shock: and will post later (after I go outside to check) the weight it took to balance it.

04-29-2007, 10:37 AM
As tire pressures have become as controversial as gun control, global warming and paper vs plastic, I hesitate to get into these discussions. I am not a tire expert. My “experts” are Michelin and Goodyear Field Service Manager-- RV specialists, & RVSEF (Recreation Vehicle Safety Education Foundation). They all work with RV tires and tire safety on a daily basis, unlike the local tire store. We are all adults here.... you believe who you want to believe.

At the big rallies (FMCA, Good Sam, Escapades, etc) there is usually a tire manufacturer rep, an RV specialist, who will give you a good education on how RV tires are made, the specs and the special circumstances that come into play for this segment of the tire industry. For those that don't “do” rallies, if you ever find yourself near one, do your best to sneak into a tire rep's seminar.

Those of you worried about over inflating a tire: yes it is possible, but blow outs from over inflation are rare. The tire is designed to have a cold max pressure and a 'working' pressure. The air pressure is supposed to increase as it rolls along the highway. The usual consequence of over inflating a tire, *not* beyond its cold max pressure, is uneven wear of the tire tread, but that only comes into play if the tire is more than 15 psi over the recommended load rated pressure.

Michelin, Goodyear and RVSEF all recommend trailer tires should be inflated to the max cold side wall pressure, as long as the rim is also rated to that max pressure. Under inflated pressures allow the side wall flexing that generates heat, a known killer of tires. Some people lower their tire pressures for the comfort of their fine china & other delicates they have packed in their trailer. You may want to rethink the loading & packing of your trailer. A blown tire causing thousands of dollars in damage, not to mention the danger of being injured or killed while disabled on the side of the highway, out weighs the softness of the trailer ride. At least in my book. Over 700 people are killed annually due to accidents while their vehicle is broken down on the side of the road.

If you know for sure the weights being carried by each tire, do the math and figure how close to the rated tire capacity your tires are. A G rated tire that has a max load of 3750lbs at 110 psi will be running at 95% of its max capacity carrying a load of 3550lbs. That means that tire is running close to its max, 100% of the time, sitting or rolling. It has been my experience that anything working at, or close to 100%, is subject to early failures. All tires on the same axle need to be inflated to the same psi.

You can find Goodyear RV tire inflation charts at www.goodyear.com.

You can find the weights of 49 Mobile Suites at the Yahoo site http://autos.groups.yahoo.com/group/mobilesuites/ under Files.

You can find “Guaranteed Tire Failure” by John Anderson, founder of A Weigh We Go, now the RVSEF, at http://www.rv-news.com/mar2000/feature2.htm

I have the most frequently weighed 5th wheel trailer in history & my tires are always at 110 psi. If I had the 17.5 in tires, they would be inflated at 125 psi. You make your choices & you choose your consequences.

Despite doing everything according to the "experts", tires still fail. I don't want to see anyone on the side of the road with a tire issue & wish everyone safe travels.

04-29-2007, 12:13 PM
bstark said
"I tentatively agree with everything you have said BUT, your LondonAire & truck experience using inflation tables was gathered with Michilin's and your 40' LondonAire probably had triple axles? If so, your load was spread over 6 tires, not four. "
No Sir ! My Londonaire was a 37RL and measured just over 40 feet. It had MorRyde 8K independant suspension axles with 4 tires.

I have compared the normal loaded weights of the LondonAire with the normally loaded weight of the MS. The MS weighs in at a total loaded weight of 15780 lbs. That happens to be 920 pounds more than the Londonaire with about the same clothes, food, toys, water and propane on board. The MS weighs in with 3380 on the pin and 6200 lbs on each of the two axles. Thats 420 lbs more pin weight plus 250 lbs across each axle than the LondonAire had. So my weights on the MS trailer tires are comparable to the Michelins.

So where does this put me? With a conclusion that the manufacturers load inflation tables might just be the way to follow in inflating my G614 tires.

Question? What has the cold inflation pressures been on most of the 614 failures ?
Best Regards

04-29-2007, 03:31 PM
Two groups of RVers.....The guys who CLAIM they check their tire pressure daily! Or, the other group...I always check mine at the beginning of the summer season before we leave home! I seldom see the first group here in our RV Resort, so I guess most are in the second group :cry: .

Tire pressure is like a religion with me. I check the pressures before we leave an RV park in the morning. Results....2 blow outs and 1 tread separation on GY G159 Load Range G tires. Tires were maintained at 110psi cold. Probably overloaded, and maybe getting old. Last blowout was in June 06 on a 2000 Avion. AND I had a GY G159 245/70R 19.5 on my International blowout, which was a front tire. Just checked for pressure 1 hour prior to blowout. I replaced the GYs on the truck with Michelin XZR, inflated to 100 psi. I keep the ES tires at 125, and even check them periodically while sitting here at the RV Resort.

04-29-2007, 04:48 PM
Tire person told me that you should be 5-7# lower than maximum tire pressure listed on tire i.e. tire rating 110# Goodyear Unisteel LT235/85R16, Load Rated G, MS 2007 SB3
Try to check each time we leave park or stop. Truck driving job just made a habit of doing it.

04-29-2007, 06:15 PM
Two groups of RVers.....The guys who CLAIM they check their tire pressure daily! Or, the other group...I always check mine at the beginning of the summer season before we leave home! I seldom see the first group here in our RV Resort, so I guess most are in the second group :cry: .

I just ran a quick check on 120 5th wheel weighs and found these numbers. 45 units had the correct air pressures, or were within 5 psi of required, 64 units had underinflated air pressures on at least 1 wheel, more than 5psi, 11 units were overloaded for the max tire load. Just thought you would like to see that your correct on the 2 groups. Those that check, and those that say they check.

04-29-2007, 06:25 PM
Ob: Sorry, I assumed when you described your trailer as a 40' er that it was a 40' model. My previous 36' was actually longer than the 38, we presently own.

I stand by my statements regarding the Michilins and the good fortune you've had using the load tables provided by them. I would hesitate however, to recommend you do the same with this OTHER brand. I have had bad experience so far using their load tables on two different trailers and two different models of their tires while enjoying 2 years of trouble free driving with the Hancooks on the previous trailer.

As Stacy has pointed out and I believe his experience and exposure through his "Weigh It" business gives him greater insight on this particular subject, I will be inflating to max 125 psi and keeping my fingers crossed!

P.S. On edit I checked the weights required to balance the new tire and it took 6 oz devided each side of the rim (front and back side) to acquire balance. I have no idea if this is out of norms.

04-30-2007, 09:04 AM
I check the cold pressure on the rig tires, both vehicles, each day before we head out. It's not hard at all and it's part of the normal get going routine just like checking the oil. I also have more than one tire gauge and will check the first couple of tires on both gauges to make sure they are reading the same or withing a couple pounds. If one gauge starts reading 5 or more off I toss it and get another. They do get wear and can change.

When I was a commercial vehicle inspector I had many truckers tell me they checked tire pressure by "thumping" the tires and can tell if they were inflated properly. My gauge said differently. They couldn't tell a full pressure "thump" from one 20 PSI under on a large tire.

My trailer tires are set at max pressure, 125 PSI on the 17.5" Goodyear's. The tow vehicle tires are set by axle load. Since the front axle on the tow vehicle is so heavy those tires are also at max pressure of 110 PSI. The drive tires have a much lighter load even when the trailer is hooked up by actual scale weight. I set them to the load pressure from the manufacturer chart plus 5 PSI. That means the rears are set at 75 PSI and they are wearing evenly across the tread. The tires on the trailer are also showing even wear.

The tires I had on the old rig were G159's which were discontinued and one of them blew. Two others showed failure wear on the tread when they developed a spot across the tread that wore the tread down to almost nothing. A good indicator of a tread about to separate from the tire. All 5 of the tires were replaced by Goodyear for the G614's