Correct method of nose-weight measurement?
Hi, I am brand new to towing and going away for the first time next week.
I am trying to come up to speed PDQ, but I am having trouble with nose-weight.
Of the 3 nose-weight considerations the car is the lowest, it is C-class 220 - W204 model - 2 door Coupe, so it is "low slung" relative to the caravan. The manual says 75Kg, but Practical Caravan says 75g to 100kg.
The first time I measured the caravan nose weight (on level ground), by putting the scale under the hitch socket and lowered the jockey wheel until the scale stop moving and it was above the 100kg, so I moved some stuff to the boot and and some to the back of the caravan (as a counterweight), this brought it down to 87kg, but it means I cant really carry anything else and we have not even tried packing our clothes or food or anything. Despite this I have been out for a couple of practice tows on local roads I know well.
After thinking about it for a couple of days, I have convinced myself I must be measuring it incorrectly because by just lowering the jockey wheel as far as it will go, the hitch is actually quite a lot lower than the height of the tow-ball on the car. So today, with out changing the contents or re-distributing the weight, I brought the car up close enough to the caravan to place a spirit level on the top of the tow-ball and the tow hitch. I then lowered the jockey wheel until the Spirit level was level. I am hoping this means that I am measuring the actual nose-weight that will be exerted on the car. The measure was less than 50kg, which I am guessing is too light.
My questions are :-
Am I now correctly measuring nose-weight?
If so, should I keep the weight at 50kg or is it better to have the heavier 75kg?
Will a heavier nose-weight help dampen/suppress the bouncing effect on my rear suspension because it makes me feel sea-sick?
Many thanks to all who are able to reply.
Comments
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If your car manual says max weight on the tow bar is 75kg then that is the max nose weight you can have. You are not measuring the caravan nose weight correctly. The caravan should be almost level when you check the nose weigh. So the easiest way to do this without a specialist nose weight gauge (which a lot of people have - look at the Milenco one) is to get a piece of wood (a hammer handle might do!) to allow the caravan to be almost level and put this under the hitch socket on the caravan and on the scales. You should aim to get it to as nearer 75kgs as possible. Remember must be with the caravan loaded ready to go. It is trial and error but you will get there.
To ease the up and down motion try to load the caravan with little of weight at the front or rear. Rule, heavy stuff low down and over the axle, light stuff at the ends. My outfit has a 100kg limit and I run it at 95kg+ with the awning, cable, aquaroll etc in the car. This subject is covered in detail in the Club handbook.
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So - i need to get the hitch of the caraven at the imaginary height of being attached to the towbar?
So, lower the jocky wheel until the hitch is at that height?
See what the weight is on the bathroom scales I'm using?And if I'm wrong, why is this so complicated???? I'm not completely stupid, i have 2 degrees!
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You need three degrees to make it in the charts.
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But are they in levelling a caravan! Do what you say, measure the height of the tow ball, no need to imagine it, then place your hammer handle or piece of wood into the tow hitch on the caravan, other end on the scales and lower the jockey wheel until all weight on the scales. Then adjust the loading in the caravan to get the correct nose weight. 75 kg nose weight is very light, mine is 100kgs, and I usually tow at 95kgs. You may have to almost empty the front storage; is the spare wheel there - out, cable there - out, ground sheet - out. Anything to reduce weight at the front of the caravan. Gas bottles could be a problem! You have to careful not to put too much at the rear in order to avoid the pitching effect. Once you have hacked it you will be ok for the future.
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when was the last time you saw them though?
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I have a W4 noseweight gauge, it is hopelessly inaccurate, so to calibrate it I stood it on my very accurate bathroom scales when I first bought it and put an indelible mark on the W4 at my desired 85Kg. 85Kg being well within both the caravan and the cars noseweight limits.
To then use it, I place it on a block of wood, so it sits at the height it would sit when coupled up to my car. On my first trip out I adjusted things within the caravan to hit the mark exactly, on subsequent trips I have simply loaded up as I did for my first trip and found it within 5Kg, so near enough. Now I only check it occasionally, or if I make some changes to what I am carrying.
Food goes in both left and right cupboard, clothes are about the same every time - All that can usually vary is where on the floor the awning goes and that sits over the axle.
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Yes, the noseweight as measured with the hitch at the height it would be, when coupled up to the car. When coupled up, my towball drops down about 1/2" so I allow for that.
The reason why you measure the weight with the hitch at tow ball height, is that if the hitch is lowered the caravan's noseweight will increase quite rapidly. Raise the hitch in the air and the noseweight becomes much lighter.
It also needs to be measured at the actual hitch - the socket where the tow ball goes, not at the jockey wheel. Measured at the jockey wheel, it would be somewhat less than the actual noseweight, because you will be measuring nearer the pivot point / the tyres.
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I am not sure that I understand why the weight at the hitch would change that much as it is raised or lowered. Surely a few inches up or down wouldn't make much difference to the weight at the hitch.
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Well, it certainly does, believe me.
Simple way to prove that point to yourself, is to weigh the nose weight on a set of bathroom scales with the nose close to the ground, then again with the nose as high as you can get it.
The pivot point is the tyres, with the bulk of the caravan above them. As the nose is raised, the weight of the bulk transfers to the rear of the pivot point and the nose becomes lighter.
By simply moving the really heavy items to the rear of my caravan, I can simply heave my caravan's nose up in the air manually, without resorting to jacks and have it sit nose up on it's rear corner steadies. The higher I lift it, the lighter it becomes. That trick is handy for any work I might need to do under the floor at the front of my caravan.
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While moving my twin axle 1800 kg caravan with the motor mover it is not uncommon to have the jockey wheel lift completely off the ground when passing over a slight inclination. This is with a static level nose weight of about 95kg.
From this I infer that the same happens when towing, and also in the opposite sense that the nose weight increases, all with a relatively small slope.
I would advise the OP to sort out the "low slung" problem as his outfit will never tow satisfactorily rigged as a downhill racer.
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I came across a couple that was in that predicament about 5 years back. I asked if they wanted help and they did. They were surprised when I said my arthritis precludes my helping you to lift but, with your permission I shall stand in your rear bathroom close to the wall (I am pretty lightweight ). They no longer struggled.
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The dynamics will apply similarly to all tow cars, and to all trailers, so the manufacturers will, I trust, do their calculations of the maximum loadings that can be withstood on a frequent basis and express the result as a figure that can be easily measured by users.
This will be nowhere near the maximum "fail" loading for the arrangement. I recall a demonstration of the tow point strength of the Discovery 3 when it was introduced where one was hoisted by crane using the front tow point, and a lifting beam was attached to the rear tow point which supported another three Discoverys. At close to three tons in those days that was over eight tons at least on the rear tow point! Land Rover rate it for use at up to 150 kg.
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Over the years I have had the jockey wheel clamp slip down the jockey wheel a few times and yes, the easy lift fix is to ask someone to simply stand in the bathroom at the rear.
I park up in my drive, without lowering the corner steadies. On occasion, two of us have gone in and two of us go in the bathroom - I have had the caravan tilt over, nose up. Something to be aware of.
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On a recent expedition the girl friend was doing the first bit of moving the caravan from it's nose-in position to get off a pitch while I positioned the Land Rover. The jockey wheel inadvertently fell into a bottomless rabbit hole, from which the motor mover was powerless to extract it.
She was concerned that she had done something really terrible when I sent her to stand in the rear washroom, but all became clear as the mover could then do what it is supposed to.
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I would worry about balancing the caravan by putting 'stuff' at the back to lighten the nose weight. Physics, and 'moment of inertia' means that a given weight will have more effect the further from the pivot, (in this case the hitch). Weight at the back is more liable to provoke side to side snaking. That is quite frightening, and not many cars have the quick power availability to pull out of it. Just my 1€ worth.
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I would worry too. No one was suggesting moving weight to the rear for actually towing the caravan, just to transfer weight temporarily to the rear, to make the nose liftable in the event the jockey wheel slipped in the clamp, or there was some other issue.
My loading of the rear end is limited to my plastic step and the Waterhog, which both travel on the floor of our shower, plus a small sealed container of drinking water - just in case.
My awning and folding chairs sit on the floor, directly over the axle. TV towards the rear of the seating at the front. Anything of any weight, is removed from the high lockers, all tinned food transferred to the floor of lockers and no containers are allowed to be partially filled with liquid. To set the nose weight, I simply move the awning back or forward along the 'corridor'.
Long ago, I was a passenger in a car towing a caravan down a hill, where the caravan began snaking and eventually turned over, lifting the rear of the car up in the air via the tow ball. Fun it was not, but it made me extremely wary of what can happen if you do get things wrong.
Pre-the Alko built in damping, I always used one of the spring types and would (on an empty road) deliberately provoke a snake, where I knew I could easily get out of it.
I scoffed originally scoffed at how effective the Alko might be for years, until I bought a caravan fitted with one. I don't scoff any more - Having spent quite a few years towing with one and deliberately trying to provoke a snake, I have never managed even a slight one. I even took my fully loaded outfit on a test track, towing at 90 with absolutely no issues.
Prior to the Alko I would always feel the sideways push when over taking, or being over taken by large slab fronted vehicles and have to grip the steering tight to respond to them. I no longer even know they are there, except by seeing them in my mirrors.
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The other thing you have to be careful about is the overall weight of the loaded caravan. You need to find a weighbridge to do this. I used to get my nose weight right by simply loading my heavy items towards the rear of the van. I was staggered to se how overweight the caravan became. The payload on many caravans is pitifully low.
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As said above - You should never load weight towards the rear, or at least further back than the axle, it causes instability.
If your nose weight is too high, simply transfer heavy items from the nose, but no further back than the axle - though I suspect mine is particularly easy to get right. My heaviest single item is the mover, which takes up a fair bit of my payload, then the awning, which leaves me with around 100Kg for everything else. The caravan though, is plated for less than it's maximum load, so I could get it uprated if I so chose.
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