LONG post (but hopefully useful!) about how to get the tongue weight right!

Discussion in 'Tow Vehicles, Hitch & Towing' started by nickap, Sep 24, 2021.

  1. nickap

    nickap Member

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    Sep 17, 2017
    This is a very long post - sorry! - but hopefully contains some useful information for other people like myself who are relatively new to campers and towing. I had not had too much trouble with the PUP we had until recently, as it was quite light and easy to tow. We recently moved to a 17' hybrid camper though, which is much heavier and taller, and while it's well below the weight that my Subaru SUV is rated to pull, it's essential to get the weights right - otherwise the towing experience can be at best stressful, and at worst, extremely dangerous. Read on for the full story ...

    I had made a rough calculation of the correct tongue weight for my hybrid camper by taking the dry weight of the camper (as listed in the specs), then adding what I estimated to be the weight of the propane, batteries, and all the gear I had packed inside the camper - then I calculated the tongue weight so that it would be 10%-15% of this estimated total camper weight. In theory this should have worked fine. However, I was then having some issues with sway from my camper, which felt to me like it might be at risk of fishtailing. This happens when the tongue weight of the trailer is too light, so I adjusted the camper load to add more weight to the tongue. This didn't help a whole lot though ... When I later got to accurately weigh the trailer and got the 'real' tongue weight, I discovered that the trailer was in fact quite a bit lighter than I had calculated - the dry weight spec I had relied on was definitely not correct! - and as a result the tongue weight was not too low; in fact it was way too HIGH, close to the maximum for the tow vehicle. As a result the back of the TV was pressed down, the front axle was light, and the result was poor handling, which I misinterpreted as a result of too low tongue weight. Overall my miscalculations were putting a lot of unnecessary strain on my TV and creating a dangerous towing situation.

    So, it's clear that it's really important to confirm that your weights are what you think they are. The best way to do this is to use a commercial CAT scale, the kind that is used to weigh trucks. I've always avoided using a commercial CAT scale, because I was nervous about looking like an idiot because I had never used one, and didn't really know how they work - I envisioned a whole row of big trucks lined up with the drivers laughing as I sweated and messed things up. In fact, using a CAT scale to weigh your TV and camper is incredibly easy. Here's what you do:

    1. Go to https://catscale.com/ and figure out where the nearest CAT scale is to you. If you're obsessive like I am, you can then go to Google maps, put in the location of the scale (probably at a truck stop off a highway) and then switch to satellite view - you can then see exactly where the scale is located so you know where to drive when you are ready to weigh.

    2. Download the Weigh My Truck app. This is a free app that is available for Android and iPhone.

    3. Go to https://weighmytruck.com/ and create an account, which includes providing a credit card number - there is no charge though until you actually weigh your vehicle(s).

    4. Drive to the CAT scale location. When I was at my local one, there was nobody there; no line, and nobody watching.

    5. Pull forward so that the front axle of your TV is on the first of the three plates of the scale, the rear axle is on the second plate, and the axle of the camper is on the third plate.

    6. Start up the Weigh My Truck app and log in to your account. Most likely the app will then automatically figure out which scale you are using based on your GPS location. If not, you can enter the number posted on the scale. The app will prompt you to enter some trailer information, like trailer number - you can basically enter anything for this, I just used 12345. Then the app connects wirelessly to the scale and after a few seconds, you see the weights of all three axles. This information is also automatically sent to your email address, so you have it for future reference. The charge for using the scale one time is around $13; if you come back and use it again the same day, it's just $3 more.

    What I did was I first loaded up my TV with all the gear I was planning on carrying in it, and then weighed that on its own. Then I went home, hitched up the camper, then drove back to the CAT scale and weighed both the TV and camper together. That allowed me to calculate the true tongue weight, based on the difference between the TV weight alone and the TV weight with the camper connected.

    Having the real camper weight and the accurate tongue weight allowed me to easily see if the tongue weight was correct based on the camper weight. What I found was that my TV was overloaded, my camper was way below its maximum cargo capacity, and the tongue weight was too high. So I took some of the gear from the TV and placed it toward the rear of the camper. That brought the tongue weight down to just about 13% of the total camper weight, and the camper overall was a little heavier and more stable on the road. The next trip I went on, the towing experience was night and day compared to how it had been before - all the feeling of instability was gone - and despite extremely windy conditions on much of the return trip, with strong side wind gusts hitting my 10 foot high camper every few seconds, I was never in any danger of losing control - the whole setup was extremely stable.

    (post continued below)
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  2. nickap

    nickap Member

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    Sep 17, 2017

    Using a CAT scale is a great way to figure out your overall camper and TV weights, but it's not convenient to do this for every camping trip, and it's really useful to be able to easily get the tongue weight when you need it. I've tried a few different ways to do this, some very expensive, and I wanted to share what worked for me and what didn't.

    Weight Safe hitch with built-in scale - e.g. https://www.amazon.com/Weigh-Safe-Fixed-Height-Mount/dp/B07J5YMLD1

    I paid $99 for one of these, because it seemed like a perfect easy solution - just connect the trailer, look at the scale, and you're all set. The trouble though is that these scales are really designed for measuring tongue weights in the thousands of pounds, and they have a margin of error of more than 50 pounds. So basically your actual tongue weight could be 50 pounds higher or lower than what is showing on the scale. That's so inaccurate that it's basically useless for weighing tongue weight of a light camper like a popup or small hybrid.

    Curt Betterweigh - https://www.amazon.com/CURT-51701-BetterWeigh-Smartphones-Distribution/dp/B081FTQCYN

    I blew another $100 on one of these, which calculates weight based on how the vehicle moves when weight as adde to the tongue. I found it was no more accurate than the Weigh Safe scale.

    Bathroom scale

    One low budget option is to use a bathroom scale. For my hybrid camper, I wanted to find one that could handle up to 500lb - I got one that was a digital scale rated up to 600lb. The trouble was, if I set it under the tongue (with a length of 2x4 acting as a support), then raised the tongue jack so the weight was transferred to the scale, the weight on the scale would increase gradually as the tongue jack lifted. The digital scale was designed to measure the weight as someone steps on the scale - so it takes the measurement something like 2-3 seconds after it first detects weight being applied. By this time the whole tongue weight hadn't been transferred to the scale because the tongue jack was still lifting - so the weight measured was way lower than it should have been.

    I then got a cheap mechanical scale which didn't have the problem of detecting the weight too soon - however, it could only handle up to 300lb. You can still weigh tongue weights of up to 600lb using this kind of scale, by using the method described here: http://hildstrom.com/projects/tonguescale/index.html. This worked, and gave the most accurate measurement so far. However, it was a pain to set up each time I wanted to take a measurement, plus I didn't really fully trust the accuracy of the cheap scale.

    Crane scale

    I had never even heard of a crane scale until I came across a post buried deep in a forum thread about towing. This post recommended using one of these over all the methods described above. I looked up crane scales on Amazon, and was amazed to find that they are really inexpensive - I got this one: https://www.amazon.com/gp/product/B01FP085C4, which was only $27. The post suggested using two stacks of concrete cinder blacks with a 4x4 between them, to hang the scale off of so that it could be suspended above the trailer tongue. I found a much easier solution though; I have an aluminum saw horse that can hold up to 1000lb, and by attaching the scale to a couple of pieces of 2x4 which were then placed across the top of the saw horse (to distribute the weight) I was able to easily attach it to the trailer tongue (I did need to raise up the sawhorse a little, so I placed the legs on some spare pieces of 2x4 that I had lying around - see photo below.) This worked perfectly - and when I measured the tongue weight with the crane scale, it was within 5 pounds of the weight I got using the CAT scale. So this is a clear winner, for accuracy, but also for ease of use - I rarely use the saw horse, so I've left it set up with the scale attached, and I can get it out of my garage and set it up in seconds. (If you don't have a saw horse like I did, you can get one like mine from Home Depot for a little under $40 - so the total cost is still well under the price of either the Weigh Safe or Curt Betterweigh scales.)

    So, this was a very long post - my apologies - but hopefully it contained some useful information that might help others like myself who are relatively new to the towing world, and maybe will save them some money by ruling out some expensive weighing methods that really don't work well!

    The winner:
    Last edited: Sep 24, 2021
    TSQ, DM27 and Sjm9911 like this.
  3. Sjm9911

    Sjm9911 Well-Known Member

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    May 31, 2018
    At least its fixed and you figured it out. It was a long journey.

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