On my caravan the spare wheel was NOT an extra, it came supplied with the van, but it was not counted in the MRO, weight. So another 21 kg including the carrier.Thanks
The spare wheel isn’t an extra
This really is a nightmare for you.
Strange as in most cases the general MIRO is as it comes out of the factory? You learn something new every day. Ours includes battery and wastemaster as we have an onboard tank and it was built after 2011.
Only the manufacturer can confirm whether the spare wheel is included or not. On another forum someone recently posted that the manufacturer had documented an unladen weight of his caravan that was over 200kg heavier than the quoted MIRO. That is probably rather exceptional, but it does demonstrate that one cannot rely on a published MIRO value. MIRO is not the ex-works weight.
I can't comment on the accuracy of your particular device, nor how it operates in reality, but the methodolgy is correct.
By coincidence in the late 80s I was approached by a transport company to design a weigh pad. This was not my day job I should mention. The principle I chose to do was the same as the Reich device. A pad which weighs each wheel seperately then totals them to produce the final result. It never got off the drawing board as they kept changing their minds and wanted to be able to have this measure the weight when the vehicle was driving over it at motorway speeds...... a weighbridge too far at the time
So again without having any hands on with the Reich device it seems to me that it measures the load on each wheel and totals them as it goes along. Which is the correct way to do it.
As an exercise you can try the principle with your bathroom scales if you have them.
First measure your weight when you stand on them with both feet.
Get a book the same thickness as the scales.
Put one foot on the scales and one on the book - record the weight. Should be roughly half the first measurement.
Face the other way i.e change the foot on the scales - record the weight.
Add the two together and it should be roughly what you got with both feet on the scales. I say roughly because your center of gravity may shift a little and you most likely will not keep absolutely still.
An observation on the use of the Reich for twin-axle caravans - the device itself has thickness, up to 45mm according to the internet - so the measured wheel will be higher than the other wheel on that side which will distort the readings and equally distort the reading when the other wheel is weighted.
So you need to arrange planks either side of the device so that the other wheel is at the same height as the wheel being measured - to be really pedantic you need the same thickness planks on the other side to prevent the tilt of the caravan affecting the reading.
So you need to arrange planks either side of the device so that the other wheel is at the same height as the wheel being measured - to be really pedantic you need the same thickness planks on the other side to prevent the tilt of the caravan affecting the reading.
I am fairly sure that the Reich scale takes that into account as it did similar with the nose weight gauge.
How can it take it into account - every caravan would be different.
45mm isn't going to shift the Centre of Gravity that much to make a difference worth considering.
Lifting one wheel by 45mm will increase the weight on that wheel and reduce the weight on the other wheel that side - caravan springs are very high rate, in terms of kg per mm, because the movement range between no load and full load is relatively small, much smaller than a car - that 45 mm is around half the total movement so could have a major effect on the meaasurement.
Only if the CofG moves and if the wheel is lifted by 45mm the CofG will move much less than this. The springs don't matter as they cannot alter the overall weight.
CoG doesn't need to move - the weight is transferred to the wheel being weighed, increasing it's apparent load - and the weight is then transferred to the other wheel when that is weighed, increasing it's apparent load.
The overall weight doesn't change, it can't - but the wheel load is measured separately with weight transfer in between.
It's faulty logic to weigh one wheel at a time unless the other wheel is blocked up to the same height.
Sorry to disagree but you can't shift weight without moving the CofG.
Conversely if you redistribute the weight the CofG will move accordingly.
Conversely if you redistribute the weight the CofG will move accordingly.
You can shift wheel load on a twin axle from one to the other without altering the CoG.
For example, assume the spring rates are 10 kg per mm and that the front wheel is on a 20mm block while the rear wheel is in a 20mm hole so the caravan is level across the axles - the load on the front wheel will increase by 20 x 10 = 200 kg and the load on the rear wheel will decrease by the same - any measurement of the front wheel will be 200 kg more than normal - if you then change the configuration so the rear is higher while it's being measured it will equally read too high - thus adding the two figures together will overstate the total weight on that side of the caravan.
The only way to use the Reich accurately is to make up planks to match the height of the Reich measuring pad.
I think my assumed spring rates and wheel deflection are of similar order to Saxo Appeal's testing and that his computed weight is over-stated significantly.
Saxo, after reading reviews on Caravan talk and on Amazon, on the Reich unit it looks like it is a 50 / 50 result for the CWC. As you are within your return envelope, and not happy with it, send it back.
Load your van with all the normal things you would take away, pots pans, chemicals, TV, etc. then weigh the van.
That is "YOUR " MRO. Then you know how much payload you have left, and can add clothes toiletries etc.
That is what I done a couple of years ago.
My postings #96 and #106. Refer I wouldn't buy a new one.
Load your van with all the normal things you would take away, pots pans, chemicals, TV, etc. then weigh the van.
That is "YOUR " MRO. Then you know how much payload you have left, and can add clothes toiletries etc.
That is what I done a couple of years ago.
My postings #96 and #106. Refer I wouldn't buy a new one.
Yeh thinking the same mate,
I’ve actually just been enquiring with some more public weigh bridge business near me
So due to the above, the calculation is much higher than it seems due to the spring pushing down on the Reich with more force then what it would be due to compression, think I’m reading that correct.
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That's Reich confirming what I was trying to suggest - it'll be interesting to see what it brings your weights down to.
If I’m returning the Reich, which is a very high chance, and which will be before we are at the caravan again to weigh…
I may just revert to the old fashion way and take to the weigh bridge again
I surrender 😉 This needs discussing over a beer. I'm used to pushing electrons around not springs.
But I can't resist a final thought. You can only compress a spring by increasing the force on it. No weight change on the static caravan, no compression.
I reserve the right to be wrong. However, I'm still sceptical that a 45mm lift on one wheel would give the discrepancy the OP is seeing.
A twin axle caravans has two springs each side - so very possible for the force on one to increase while the force on the other decreases by the same amount - the inaccuracy occurs when you're only weighing one axle at a time and then switching the forces around before weighing the second axle.
If the overall height is 45mm the load cell (the bit the wheel sits on) appears to be around half that. I'm confident that raising one wheel (on a twin) will increase the load on that wheel but I have no idea by how much. I'd speculate that it will vary from caravan to caravan depending on chassis, suspension and weight.
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