Weighing - RV-Dreams Community Forum

Cattntitans · RV-Dreams Community Member

Weighing

carolinakids · RV-Dreams Family Member

www.rvsafety.com/weighing/weighing-schedule

RonC · RV-Dreams Family Member

The ideal way is to get it done by people who do that all the time with special weighing pads. They are often found at various rallies around the country. The "do it yourself method" is to go to a regular CAT scale, found at many truck stops, and after weighing the whole rig, pull the trailer forward until the front axle of the trailer is on the weigh pad of the one that the trucks rear wheels were on and the back trailer axle remains on the trailer pad (this is called splitting the axles). After this is done, back the rig up and maneuver the trailer so that the tailer axles are again split, but one side of the trailer's axles are OFF the weighing pads. In this way you'll have the front trailer axle total weight, the rear trailer axle total weight (obtained when you first "split the axles"). Now subtract the one side weight of each axle (from when you spit them with one set of side tires off the weigh pads). This will give you (with a little math) the front truck axle weight, the rear truck axle weight, the front trailer total axle weight, the rear trailer total axle weight, and after the math, you'll have each trailer tires individual weights.

This requires some skill to put one side of the trailer wheels off the pads and be split at the same time ... so if you aren't adept at maneuvering the trailer in tight spaces best not to try this. I have done it and while it yields the individual wheel weights, it will require that you pay for three weighs ... the first "regular" weighing, the first split axle weighing and finally the split axle weighing with one set of trailer tires off the side of the weighing pads. Have a spotter, and if this exceeds your comfort level of trailer/truck control don't do it. Probably should go inside first to tell the scale operator what you are intending to do, as he/she will need to co-operate with you to get this done. Sometimes, best to weigh the whole thing, then pull forward to split the axles ... then pull off the scales to allow others to move on, then pull back on the scale to obtain the final split axle with one side of the trailer off the weigh pads to get your final numbers.

Good luck.

-- Edited by RonC on Thursday 9th of February 2017 05:10:04 PM

-- Edited by RonC on Thursday 9th of February 2017 08:21:05 PM

Second Chance · RV-Dreams Family Member

RonC wrote:
The ideal way is to get it done by people who do that all the time with special weighing pads. They are often found at various rallies around the country. The "do it yourself method" is to go to a regular CAT scale, found at many truck stops, and after weighing the whole rig, pull the trailer forward until the front axle of the trailer is on the weigh pad of the one that the trucks rear wheels were on and the back trailer axle remains on the trailer pad (this is called splitting the axles). After this is done, back the rig up and maneuver the trailer so that the tailer axles are again split, but one side of the trailer's axles are OFF the weighing pads. In this way you'll have the front trailer axle total weight, the rear trailer axle total weight (obtained when you first "split the axles"). Now subtract the one side weight of each axle (from when you spit them with one set of side tires off the weigh pads). This will give you (with a little math) the front truck axle weight, the rear truck axle weight, the front trailer total axle weight, the rear trailer total axle weight, and after the math, you'll have each trailer tires individual weights.

This requires some skill to put one side of the trailer wheels off the pads and be split at the same time ... so if you aren't adept at maneuvering the trailer in tight spaces best not to try this. I have done it and while it yields the individual wheel weights, it will require that you pay for three weighs ... the first "regular" weighing, the first split axle weighing and finally the split axle weighing with one set of trailer tires off the side of the weighing pads. Have a spotter, and if this exceeds your comfort level of trailer/truck control don't do it. Probably should go inside first to tell the scale operator what you are intending to do, as he/she will need to co-operate with you to get this done. Sometimes, best to weigh the whole thing, then pull forward to split the axles ... then pull off the scales to allow others to move on, then pull back on the scale to obtain the final split axle with one side of the trailer off the weigh pads to get your final numbers.

Good luck.

-- Edited by RonC on Thursday 9th of February 2017 05:10:04 PM

-- Edited by RonC on Thursday 9th of February 2017 08:21:05 PM

Ron - you're right. The easiest way is to utilize one of the services at the rallies or the Escapees SmartWeigh programs. As to the methods you describe... I just pulled through a CAT scale yesterday and there was signage prohibiting such practices.

Rob

Cattntitans · RV-Dreams Community Member

Thanks you all for your posts. We will probably try to make the Crossville TN rally in May to weigh. We take possession of our 2016 Montana High Country on Monday. So excited!!!

Neil and Connie · RV-Dreams Family Member

In addition to the other suggestions…if you're ever in Texas the Escapees home office does wheel by wheel. As to the method of multiple weighings on a CAT scale with wheels off of the pad…I'm sure that's possible on some scale setups as I've seen it talked about numerous times. However…we've had our rig on 4 different CAT scales over the years for various reasons and none of the 4 we used would have allowed that as there some posts on the side that prevented it…I've also looked at probably another dozen or so to see if it would even be possible and have found no scale we could have done the trick with. You could do an axle by axle weighing pretty easily by positioning the trailer front to rear…but side to side means you have to find a scale that allows you to do that.

Axle by axle is better than nothing though…but you gotta figure the drivers side (or whichever has the kitchen on it) is usually heavier. We've only had one wheel by wheel weighing…and our drivers side totaled 8900 and passenger side 7225. When we weighed ourselves via CAT again after getting our new truck I came up with 17,500 on the axles vs the 16,100 on wheel by wheel back in 2013. We were mostly dry of water the first time and mostly full the second time…so I just used the same distribution percentages as back in 2013 and estimated our wheel weights from that…so that I could verify the right tire pressure number and that we weren't overloading any tire or axle. We aren't…but as I said that's with full water and mostly full waste tanks and we would never actually travel in that condition. Normal for us is 30 or so gallons of fresh and we almost always dump before traveling unless we're doing a series of daily drives with overnight stops…and even then we dump every 2 or 3 days maximum so never over 1/3 to 1/2 full on waste tanks.

RonC · RV-Dreams Family Member

Rob, I have never seen any instructions or restrictions signs at the scales I have used. Only "enter" and "do not enter". The usual lack of instructions makes the use of the scales to weigh your RV pretty mysterious unless you get an explanation from someone or are a "just go for it" type. 😜 What was the verbiage on the sign that prohibited "such practices"? Split axle weights is very common in the trucking world, and only you know if one side is off the weight pads. Just curious.

Bill and Linda · RV-Dreams Family Member

I completely agree that weighing on a CAT scale is better than not knowing anything. We've done it several times to check pin weight. However, I've seen demonstrated how inaccurate weights can be if the trailer and wheels are exactly level with each other both side to side and between wheels on he same side, etc. Don't want to go into a lot of detail but just to say if one can get wheel by wheel done, correctly, by people who know what they are doing, the results will be much more accurate.

Recall, if one has 7K axles the single side rating, which is the one that actually matters, is 3,500lbs. It doesn't take a lot of error to be way off when the number is only 3,500 if you follow me. So I'm just providing a perspective. CAT scales are accurate but are designed to deal with axle weights in the 20K DOT limit per axle range. It is not that they are inaccurate it is that it is really difficult to get an accurate individual wheel weight when the numbers are in 3,500 or 4,000lb limit range for 7K or 8K axles. Naturally, YMMV

Bill

RonC · RV-Dreams Family Member

Bill,

Good point re:accuracy of the scales. Like torque wrench's and air pressure gauges, scales are designed to be "most accurate" at the sweet spot of the anticipated weights (usually in the middle of the range) ... when you get to the far ends of the operating range (either way) the accuracy degrades. Probably no more than 1 or 2%, so 1% of 3500 lbs is only 35 lbs, so the accuracy is reasonable but not perfect.

-- Edited by RonC on Saturday 11th of February 2017 12:34:18 PM

Bill and Linda · RV-Dreams Family Member

RonC wrote:
Bill,

Good point re:accuracy of the scales. Like torque wrench's and air pressure gauges, scales are designed to be "most accurate" at the sweet spot of the anticipated weights (usually in the middle of the range) ... when you get to the far ends of the operating range (either way) the accuracy degrades. Probably no more than 1 or 2%, so 1% of 3500 lbs is only 35 lbs, so the accuracy is reasonable but not perfect.

-- Edited by RonC on Saturday 11th of February 2017 12:34:18 PM

Ron, let me clarify. I'm not really talking about the accuracy of the CAT scales themselves at the lower end of their range. I have no specific information or claim about that factor one way or another. What I am saying is if the wheels are not level, that is any one tire physically higher than another, the weight numbers will be off as the "higher" wheel will be taking more weight then the lower one.

To expand - we have a three axle trailer. When we had H & L weight it back when they did that I got a "nice" but, "oh dear," look because, having only 4 scales they needed to put leveling blocks under our third axle to make sure the wheels were level with the two front axles. After taking those two front axle tire weights they had to move the leveling blocks to the front axle and move the scales to the rear axle keeping a set of scales still under the middle axle. The difference in height of a wheel with and without a scale under it could cause a measurable inaccuracy in the individual wheel weights. H & L were well trained in the proper way to weigh trailers, trucks and MH's etc.

So all of this is the reason I say, while I have used CAT scales and believe they are a fair "indicator," putting a rig half-on or off a scale is probably not the best way to get the most accurate measurement for our RVing purposes. But still, much better than hoping all is OK.

Again, just trying to shed a bit more light on this for those reading along.

Bill

Second Chance · RV-Dreams Family Member

RonC wrote:
Rob, I have never seen any instructions or restrictions signs at the scales I have used. Only "enter" and "do not enter". The usual lack of instructions makes the use of the scales to weigh your RV pretty mysterious unless you get an explanation from someone or are a "just go for it" type. 😜 What was the verbiage on the sign that prohibited "such practices"? Split axle weights is very common in the trucking world, and only you know if one side is off the weight pads. Just curious.

Ron,

It was the bollards close on the port and starboard sides that prevented getting wheels off the scale pads laterally. I don't remember the exact terminology on the sign (just before the call button), but in included the word "prohibited" and indicated they wanted you to use the three scale pads as intended.

We've had the fiver weighed at Rainbow's End in Livingston, so we know the wheel-by-wheel weights and that the street side is almost 1,000# heavier than the curb side - and we don't/can't change that load distribution much. With the MOR/ryde suspension and load range G tires, we don't worry about that part of it much these days, anyway. What we did have to worry about was pin weight. We were at the limit on the rear axle of our 2500HD. This week, I was pulling the F-350 DRW across the scales to get base weights to know where we now stand. With full fuel, the hitch, a box in the bed with the stuff it's going to carry, and two occupants, we now have 5,080# leftover payload for the pin and 21,100# remaining on the GCVWR (though I would never want to do that!). Unless we trade fivers or change our living/packing habits, I may not be spending too much at the scales for a while...

Rob

Howard · Host

There are just a few teams that weigh wheel-by-wheel. RV Safety & Education Foundation is the best and they often have teams at the largest RV rallies across the country. If they don't have scheduling conflicts, we have them at our RV-Dreams Rallies. Next best is the Escapees SmartWeigh program. Escapees has permanent locations in TX, SD, & FL and they weigh at their Escapees Escapade Rallies and some other smaller Escapee Rallies. They will have a team at our 2017 Spring Rally in Sevierville, TN in May to weigh.

There are a few other wheel-by-wheel services out there, but I'm not familiar with their training, processes, and procedures, so I can't comment on them.

As far as the CAT scales, that option is certainly better than nothing, and they can give you accurate axle and total weights. However, they DO NOT allow you to weigh wheel-by-wheel by splitting your rig down the middle with one side on the scales and the other side off. On the CAT Scale "How To Weigh" web page, they say this:

MOTORHOME WITH TOW CAR

When weighing your motorhome and tow car, the motorhome must be completely on the scale and it is best if you position the steer axle (front wheels) of the motorhome on platform 1, and the drive axle or rear axle of the motorhome on platform 2. The tow car will normally show up on platform 3.Please note: Our scales can give you axle weights and a total gross weight, however, they cannot weigh each corner of the vehicle. We cannot provide individual wheel weights and, to prevent damage to your vehicle as well as our scales, do not allow that type of weighing.

The How to Weigh web page provides descriptions on how to weigh each type of RV combination in addition to the commercial trucks. And in all descriptions for RVs they indicate ".... must be completely on the scale ....".

Thanks for your interest in safety! :)

SamK · RV-Dreams Community Member

If you are in OH, consider Weber Son & Service Repair Inc. for your RV weighing needs. They are very popular.

Danny and Cheryl · RV-Dreams Family Member

All Cat scales are Certified Scales, they will go to court with you if you get an overweight ticket. Am I missing something? What difference does the side to side weight matter, there isn't anything much you can change.

Howard · Host

Danny and Cheryl wrote:
All Cat scales are Certified Scales, they will go to court with you if you get an overweight ticket. Am I missing something? What difference does the side to side weight matter, there isn't anything much you can change.

You can easily be overloaded on one end of the axle or on individual tires/wheels. And yes, there are many things you can do to distribute or remove weight. The biggest advantage of wheel-by-wheel weighing is knowing if you have tires that are overloaded or under-inflated for the load they are carrying. Wheel-by-wheel weighing lets you know how much weight each tire position is carrying so that you may 1) reduce load, 2) redistribute weight, 3) inflate to proper tire pressure for the load being carried (but no more than sidewall maximum), or 4) upgrade tires/wheels to higher load range to accommodate the load.

Though it is recommended to run tire pressures at maximum sidewall pressure on towables, the only way to know the correct tire pressures on RVs is to 1) know the load the tire is carrying and 2) use the load/inflation tables for the tires from the tire manufacturer.

Check out Goodyear RV Tire website - "Weighing Your RV" and this is from the Michelin RV Tire website:

Axles & Tire Pressure

Michelin displays tire loads per axle end in the load and inflation tables. We recommend weighing each axle end separately and using the heaviest end weight to determine the axle's cold inflation tire pressure. For control of your RV, make sure tire pressures are the same across an axle, while NEVER exceeding the maximum air pressure limit stamped on the wheels.

We have the advantage of having been involved in the RV weighing process for four years and know the statistics and potential issues with overloaded RVs and overloaded tires, axles, tow vehicles, etc.

Hdrider · RV-Dreams Family Member

There is a permanent Smart Weigh at the Escapee park in Congress Arizona also, in fact we will be getting our coach done here this coming Thursday. They also measure height at the same time.

Bill and Linda · RV-Dreams Family Member

Danny and Cheryl wrote:
All Cat scales are Certified Scales, they will go to court with you if you get an overweight ticket. Am I missing something? What difference does the side to side weight matter, there isn't anything much you can change.

In this tread, and many others on this forum, it has been explained the axle ratings of say 7K or 8K are actually limited by the single side weights. 3,500lb for a 7,000lbs axle and 4,000lbs for an 8K axle. If one exceeds those individual side numbers the "axle," per DOT rules, is overweight because of the weakest component rating. This per MOR/ryde when I asked them about this and other related suspension questions and ratings. This "lowest rating" number is based on the lowest rating of any single component in the suspension system.

As an example, my tires are rated at 4,805lbs - the hubs are rated at 4,000lbs but the suspension, being a 7,000lb per axle suspension, is rated at 3,500lbs per side. Therefore while my total axle capacity might be 21,000lbs as I have 3 axles, each individual axle "side" must not exceed 3,500lbs. That can't be measured on a CAT scale.

CAT scales are accurate but they can't measure individual wheel weights as Howard's quote from the CAT website states. The "we'll defend you in court part" concerns semis and the 20,000 lbs max per axle law along with other wheel spacing weight issues not applicable to almost any RV.

I hope that explains it. The fact one "can't change anything," other than off-load some weight or increase axle ratings by replacement, doesn't negate the fact that if something is overloaded it could break and cause a dangerous situation. I've seen an axle side fail. It isn't pretty and can be very dangerous - and expensive.

carolinakids · RV-Dreams Family Member

We went to the RVSEF website Howard and Linda gave us at Severville and found a couple in St. Cloud, Fl. we are visiting them Sunday for a weighing of the RV. They work fulltime so they only weigh on Sat. And Sun. Also took advantage of the free camping.net site and found some Florida Water Management land and got permits to camp on them. Do a little boondocking on the way back up Florida. Got to remember to fill fuel tank of truck and dump all waste and water.

RonC · RV-Dreams Family Member

Second Chance wrote:
RonC wrote:
Rob, I have never seen any instructions or restrictions signs at the scales I have used. Only "enter" and "do not enter". The usual lack of instructions makes the use of the scales to weigh your RV pretty mysterious unless you get an explanation from someone or are a "just go for it" type. 😜 What was the verbiage on the sign that prohibited "such practices"? Split axle weights is very common in the trucking world, and only you know if one side is off the weight pads. Just curious.
Ron,
It was the bollards close on the port and starboard sides that prevented getting wheels off the scale pads laterally. I don't remember the exact terminology on the sign (just before the call button), but in included the word "prohibited" and indicated they wanted you to use the three scale pads as intended.
We've had the fiver weighed at Rainbow's End in Livingston, so we know the wheel-by-wheel weights and that the street side is almost 1,000# heavier than the curb side - and we don't/can't change that load distribution much. With the MOR/ryde suspension and load range G tires, we don't worry about that part of it much these days, anyway. What we did have to worry about was pin weight. We were at the limit on the rear axle of our 2500HD. This week, I was pulling the F-350 DRW across the scales to get base weights to know where we now stand. With full fuel, the hitch, a box in the bed with the stuff it's going to carry, and two occupants, we now have 5,080# leftover payload for the pin and 21,100# remaining on the GCVWR (though I would never want to do that!). Unless we trade fivers or change our living/packing habits, I may not be spending too much at the scales for a while...

Rob

Rob,

You are right about the bollards ... that is the only thing that makes getting the wheels off to one side difficult, and they are what make this maneuver challenging. When I did it, I had a SRW truck. Now that I (like you) have upgraded to a DRW truck, I'm not sure if I could do it again. I do remember that in order to clear the truck by the bollard, I had to fold the drivers side mirror and only cleared it by inches. The next time I get it weighed, I'll probably use a professional service.

-- Edited by RonC on Tuesday 14th of February 2017 12:36:21 PM

carolinakids · RV-Dreams Family Member

On our way back to North Carolina from Miami and so we looked up weight crews and found a couple outside Orlando at St. Cloud, Fl. Scheduled an appointment and stopped by and 15 mins we were done and back on the road. Very nice couple and helpful in explaining the numbers. Got all green numbers so we are happy. This being our second time weighing and with a newer and bigger RV, I can see where theres a lot of folks out there over on there weight. We are close in maximum weight capacity and have a 35 ft. unit with a F-350 DRW. Now I see why when we first meet Howard and Linda and they asked if we had weighed why they stressed so much on the weight numbers. Its scary in seeing my weight with a 35 ft. unit and some other RV'ers hauling 40 plus and the same truck we have or the Dodges or GM products.

Another thought is the truck hauling over tonnage. I hauled tonnage all my working career. I know what over tonnage was like with the trains. I can only imagine what my truck is feeling with some nut like me trying to maintain highway speeds. I sure thank Howard for stressing the importance in knowing what we weigh. Thank again our RV'ing friends.