the dreaded tire topic...

brulaz wrote:
Thanks John.

Don't recall having seen a CAT scale set up with such a wide flush open area next to the scales. But will keep my eyes open.

EDIT: hmmmm, a bottle jack with gauge may be the way to go ...
Bottle jacks with gauge port
or
Youtube video

Yes, those will work you just have to get a gage in the correct pressure range and figure out the piston diameter. Boy, they have a U tube for everything now a days....

Here are the basic steps, need a hard surface that is flat. Level the camper. Drive up on 4, 2 x 8's or wider


Now set the force jack under the axle seat, use a feeler gage or sheet of paper to "just" be there. You do not want to lift and you do not want to be very much low. I used a 0.001" feeler. Lock the jack


Now jack up the camper at that wheel by the frame and pull the 1 2 x 8.




I also used a bottle jack, easier to control


Very slowly lower the jack to lower the camper onto the force jack. Read the gage




Then jack camper back up, slide 2 x 8 under tire, release force jack and move out from under the axle seat, slowly lower camper back down. Move to the next wheel.

When your done, you need to measure from the jack point at the axle seat to the center of the tire. Then calculate the reduction of force out at the wheel. (summat moments about a point) If you need
help with this let me know.


A link to a bigger image so you can read it.
Larger size

Things that will affect the force.

• Air in the jack, make sure there is none in the hydraulics.
  
• A non solid surface. If the jack base compresses into the ground it changes the load as the entire trailer will shift some and the equalizer can shift a little load.
  
• The gage itself, ideally you are mid range of the pressure gage for best accuracy.
  A rubber equalizer. These "settle". So when you jack up the camper, the rubber uncompresses. When you lower it down, the rubber starts compressing and takes time to settle into it's loaded position. As the rubber is compressing, the spring load if shifting some to the other wheel location. I finally had to measure with a caliper 3 decimal places where the settle in width across the equalizer was to get a repeatable reading. Drove me nuts until I figure this out. And you have to wait a fair amount of time too.

I did not dream this method up, but I did enhance it. Member EX Rocket Scientist dreamed it up with his Sherline tongue weight scale.

Good luck

John

Thanks John.

Don't recall having seen a CAT scale set up with such a wide flush open area next to the scales. But will keep my eyes open.

EDIT: hmmmm, a bottle jack with gauge may be the way to go ...
Bottle jacks with gauge port
or
Youtube video

brulaz wrote:

JBarca wrote:

Start by weighing each wheel location.
Upgrade load range as needed to be 20% or more reserve capacity above the heaviest tire.

Was thinking the same thing a while back and looked for portable single wheel scales online. Very nice but very pricy. Have been religiously going to CAT Scales over the years but they have all been single axle, not single wheel. And our local landfill scale is similar.

So how/where do you weigh a single wheel?

I know of 4 ways. 2 I have used.

1. Find a buddy who has a race car and ask him if he/she can bring their scales over some day. Often race cars use the portable scales. The buddy who has them that I know is several states away...

2. If you have a force jack, this is a jack with a fancy pressure gage that reads out directly in pounds. There is a method where you put the camper up on 2 x 8's, then one wheel at a time jack up the camper by the frame, remove the 2 x 8 and let the axle seat down on the force jack which is just under the axle seat, the gage reads out in pounds. Then do some math to get the weight at the wheel to compensate for the axle seat to wheel distance. I have done this, there is some error in it if you have a rubber equalizer. This method can be off ~ 50 to 75#, but I can do it in my yard. If you want more on this let me know.

3. The method that most can do if they have a CAT scale near them setup like this.


You need at least a 3 segment semi scale. This pic is from me explaining WD setting but you can see the segments.


Now for your first reading. Make sure you have the WD bars on if this is a TT and loaded with water or what ever your max is. You start by splitting the front and rear axle. Pull up enough to get 1 axle on each scale. The scales split is between the 2 axles. Take a weight reading. Now pull off and go around again.

Sorry don't have the camper on it but you can get the drift from this pic. There is to be nothing else on either of the 2 scales.


Now you know the total load the front and rear axle are under. Just not individual wheel weights yet.

Now pull on and leave 1 set of tires off the scale. The scale setup has to allow this. I use to weigh at Flying J and they had guard rails next to the scale. Could not do this. Then a year or so ago they upgraded to CAT scales and the new flush pad next to the scale came.


Now you have the right side wheel individual weights. To get the left side you have 2 options, go around again and pull off the other side. OR subtract the front right individual weight from the front total axle to get the front left. And do the same for the rear axle.

Ideally you go inside and talk to the scale manager first so they know what you are doing and OK it. There is 20 to 50# of error in this as the scales are calibrated and meant to weigh 80,000# semi's and 50# to them is noise.

The 4th method. If you can find this organization, they do just this. RESEF http://rvsafety.com/ I myself have never been to one, would like to some day. I know some folks who had this done to their rig at a rally.

Hope this helps

John

JBarca wrote:

Start by weighing each wheel location.
Upgrade load range as needed to be 20% or more reserve capacity above the heaviest tire.

Was thinking the same thing a while back and looked for portable single wheel scales online. Very nice but very pricy. Have been religiously going to CAT Scales over the years but they have all been single axle, not single wheel. And our local landfill scale is similar.

So how/where do you weigh a single wheel?

JJBIRISH wrote:

fla-gypsy wrote:

JJBIRISH wrote:

JJBIRISH and I seem to have similar opinions and had the same bad experience with Duro tires. Unfortunately jumping to a LT tire was not an option for me like a lot of folks. I have taken my improvements as far as possible with Maxxis 225/75R15E's. Fresh, new, 2013's went on this morning. I am fortunate that the manufacturer of my cheapo, base line Keystone Hornet TT spec'd it with running gear exceeding the total GVWR of my TT and I now have wheels, tires and axles with the same rating. With my tongue weight added in I now have a minimum 15% reserve margin and it is all I can do.

I fully understand your pain… fortunately I have the room for the upgrade if I need to, but I am comfortable with the Maxxis I am using for the time being…

I believe you will be happy with your Maxxis selection to, mine have held up extremely well… they are 5 years old (boy it’s hard to believe how fast the time goes by) now and in great shape, and yes mine came with sufficient running gear to…

The set of M8008 D's that came off were 6+ years old and served me very well. It made the selection very easy.

I've been towing with a 1965 Chevy Van since 1988, using 14" car tires. Way back (1990) I always used Goodyear Arrivas, which was a heck of a tire. I still have one I use for a spare, it shows no sign whatsoever of cracking at all, still looks new. The closest thing to it I found at Les Schwab, a 50,000 mile Classic Steel Belted Radial with plenty of capacity to handle our 3600 lb van and 4300 lb Wilderness TT. Never had a blowout in all my years of towing. I have to agree with JJBirish, tires are being made very cheaply these days so they blow out if people are towing too fast or not keeping them inflated properly, or running over curbs, or leaving them out in the sun, etc. I've been towing for 25 years, and I can't remember ever worrying so much about what tires are best, what date they were built or how many years they will last before falling apart. Shoot, when I started we still used bias ply for trailers and the big debate was whether or not radials would be better. Kinda wish China hadn't discovered that capitalism works better and makes 'em lots more money than communism.

16in Bridgestone Duravis R250 Rge E - steel casing, nice sidewall protection. They are carrying about 75%- 80% of their load rating and barely get warm at 70F ambient temp cruising at 65mph.

FastEagle wrote:

JBarca wrote:


The sad part is, running gear upgrades do not show up in too many camper brochures. You can not sell it, if it is not offered. Some are finally coming with rubber equalizers, shocks and I even saw self adjusting brakes but they are far and in-between. I have yet to see an adjustable axle seat even though they have been around a long time. And they still keep using these light duty hangers and frame attachments.

Just maybe RV trailers are built to the specs required by their weight and usage factors. The engineering analysis for RV trailers does not require a background for self propelled vehicles. Engineers for the RV trailer industry come from the same schools as those designing cars and trucks.

Take a look at pages 27 - 30 in the reference. Looks to me like that's a pretty good explanation of a simple system to support an RV trailer.

Click Here

FE

Hi FE,

Thanks, that is one nice camper. Boy, thats a beauty. Mobile Suites I would put in the high end RV trailer. And in that type of quality, upgrades come as standard.

From the catalog you posted. Things that caught my eye.

First the tires, using their words

Mobile Suites wrote:
Heavy-duty 17.5" Goodyear® tires provide
increased load capacity while staying cool on
long hauls. We use truck tires, not RV tires, to
ensure better performance and peace of mind

Note the truck tires note.

They have oil bath bearings.
They have greaseable suspension bushings with grease fittings.
Kodiak disk brakes
15 in. wide stacked structural tubing frame. That is a big difference.
Extra frame cross members to not twist the frame rails.
8,000# axles. I cannot find the GVWR specs but assuming a triple axle is still at or under 25K. I would think over 25K may push the need of a CDL.
They use Mor ryde IS suspension. A totally different league than most TT's

When you used the words "simple system to support an RV trailer" what is on that Mobile Suits 5er is not what is on the majority of TT's.

I have great faith that the RV engineer can build a quality TT RV frame and running gear system and it will not cost that much more then what the average TT build when purchased at the OEM level. This all comes down to $$ and who is making it. That is fine, offer it to the customer, tell them the advantages of why and they might just buy it. Or will it open up all the questions of why don't they just include them?

JBarca wrote:


The sad part is, running gear upgrades do not show up in too many camper brochures. You can not sell it, if it is not offered. Some are finally coming with rubber equalizers, shocks and I even saw self adjusting brakes but they are far and in-between. I have yet to see an adjustable axle seat even though they have been around a long time. And they still keep using these light duty hangers and frame attachments.

Just maybe RV trailers are built to the specs required by their weight and usage factors. The engineering analysis for RV trailers does not require a background for self propelled vehicles. Engineers for the RV trailer industry come from the same schools as those designing cars and trucks.

Take a look at pages 27 - 30 in the reference. Looks to me like that's a pretty good explanation of a simple system to support an RV trailer.

Click Here

FE

JJBIRISH wrote:


While switching to the LT tire can be a good move, it just isn’t possible for some, and it is costly for all…
Even though I agree with John, and tireman on the reporting and think it is important to do so… it is so wrong in so many ways that it takes changing tire types to be or even just to feel safe and comfortable…

Reporting won’t bring the needed change… the only thing that will cause meaningful change is US… if we don’t demand better, if we don’t make it a deal breaker, if we don’t start to insist, you will never get nor could you ever expect better…

Yet I talked to my dealer and another local dealer yesterday, and both say they are never even asked about what type of tires they have and they both say unequivocally they have never ever had anyone demand LT tires as a condition of sale, or even a upgrade to a LT tire…

So IMHO there is plenty of blame to go around for the cause of the problem but we are the blame for the lack of a cure… we have done precious little to pressure the tire or the trailer industries, and when buying replacements our first question is how much…

Hi JJ,

Yup I agree with ya. Proper running gear is not a sales point. Power awnings, interior conveniences, creature comforts etc are selling points.

While I hope it is not impossible...I doubt many new camper sales or PDI's even talk about running gear, not alone tires. During the PDI where you ever told the brakes on the camper are manual adjust, to make sure you have proper TW and balance as you load the camper, the fact that the camper did not come with very much grease in the bearings and make sure you come in soon for an service appointment, make sure you weigh the axles when you load the camper so you do not overload these axles we put on, the list goes on.

If I ever do buy a new camper, I do not know yet what I'm going to run up-against but unless the gas economy goes totally off the charts, the camper size will be in the same league I am now. There will be a discussion about running gear and LT tires. The list of brands I'm even considering is small due to the TT quality and I'll wait for it to be built if need be. And yes, I know I have to pay something more. I might be a minority, but it will happen. There is nothing left much original in my running gear. OK the springs are still the same....

The sad part is, running gear upgrades do not show up in too many camper brochures. You can not sell it, if it is not offered. Some are finally coming with rubber equalizers, shocks and I even saw self adjusting brakes but they are far and in-between. I have yet to see an adjustable axle seat even though they have been around a long time. And they still keep using these light duty hangers and frame attachments.

As far as NHTSA, they get very few complaints. For us towing campers, tires are a big deal when a failure happens to us. I know compared to the auto industry we are a spec of the problems they have to deal with. If no one is complaining, what are they going to focus on? Many of the reports that are filed, lack correct information. I was ignorant too. Until my tire failure I did not even know how or where to file a complaint or that I should. I really wish government doesn't have to force regulation to make a quality trailer tire.

I agree "WE" the folks who use campers are the ones that have to help the cause. The 1st part is helping to spread the understanding. Like this post.

Bigcitypopo now has a little better understanding, hey that's progress. One camper at a time.