# Hymer 644G-should I worry about weight restrictions?



## 104305 (May 6, 2007)

Recently whilst at a motorhome show sheltering from the rain I got into conversation with a chappie who point blank refused to entertain any motorhome with a garage space and a fixed transverse bed above it. I asked why and he said that the garage was a total waste of space due to its miserly inability to carry any weight due to the payload restrictions once the van is loaded with its normal "stuff". Whats the point he said of having a garage when you cant hardly load anything in it! Mmmmm! I thought have I been wrong all these years, perhaps breaking the law even. My garage is filled to the brim with all manner of motorhome paraphenalia when we go for an extended stay plus the Smart car on the trailer behind. Ive never considered the weight in a big way except for once putting it on a weigh bridge prior to travelling to Italy. Ive always considered the Hymer 644G well within the limitations to carry all my motorhoming needs. His mention also of French police stopping carefree British motorhomers for a weight check, fining them and informing other French police to stop them on their journey to repeat the fines gave me some cause for concern. Is this really what happens? Should I even be towing my Smart car all be it on a Briam James Smart car trailer? Am I over loaded to the hilt? So all you experts out there what do I really need to do, and do I really have to worry to much. Should I go on the weigh bridge prior to every time I go abroad especially when travelling thru France? What are the figures I need to check on that plate with weights and dimensions on. What numbers do I need to subtract to get the max permissible payload and what figure should I look for when on the weighbridge. Oh and is the car and trailer also considered part of the payload. One more thing this chappie also said that with the Hymer 644G anything over its max and I should be using some sort of HGV licence, this really got me thinking!!


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## eribiste (May 1, 2005)

On the right hand side of your bus, near the front wheel, you should find the 'rating' plate that gives you the Maximum Authorised Mass, almost certainly 3500 kg, unless yours is uprated. you will also find a maximum for axle 1, the front axle and a maximum for axle 2, the rear axle. If it's a tag axle job, there will be a figure for axle 3 as well. You will find that if you add axle 1 to axle 2 the figure will exceed the Gross Vehicle Weight. This doesn't mean you can exceed the MAM! Your vehicle must not exceed the MAM under any circumstances. 
The axle weights are the maximum loads for each axle. The procedure on a Ministry weighbridge is to drive very slowly over the weighing doo-hickey. This gives the man with the white coat each axle weight and the total weight of the test vehicle.

Let's say that your bus has an axle 1 rating of 1200 kg and an axle 2 of 2650 kg. If, on test, you get 1000 on the front and 2650 on the rear, neither axle is overloaded but your GVW is over by 150kg.

You dump some stuff. Now you get 1100 on the front and 2300 on the rear. No problem, everything is in the green.

Then you put your 100 kg scooter on a rack with a bit of an overhang and try again. 2780 on the rear, 700 on the front. You're in the GVW, but your rear axle is now overloaded. No scootering for you!

The trailer is a seperate issue, except that the trailer will be designed to give about 70 kg or so load on the tow bar hitch, and this obviously sticks out at the rear a bit, increasing the leverage over the rear axle.

I hope this helps a bit, or does it cause even more confusion?


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## davesport (Nov 12, 2006)

Have a look at my post here for my findings on a similar van.

D.


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## davesport (Nov 12, 2006)

Have a look at my post here for my findings on a similar van.

D.


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## JockandRita (Jun 1, 2005)

longdistancerunner said:


> Oh and is the car and trailer also considered part of the payload. One more thing this chappie also said that with the Hymer 644G anything over its max and I should be using some sort of HGV licence, this really got me thinking!!


Hi there LDR,

Good advice given by those above.

Your car and trailer come into what they call the "Gross Train Weight", (GTW) this is the maximum weight of the MH and any trailer it is towing, (including A frames).
For example, our MAM is 4,500kg and our GTW is 5,200kg. This only leaves a maximum towing weight of 700kg, however, if we don't load up to our MAM, that would allow an increase of the towing weight, so long as it did not exceed any of the axle weights, nor the GTW.

SVTECH informed us that we could replate our Hymer Tag to 5,000kg without any modifications at all, however, this action would not increase the GTW. That stays at 5200kg. 

Re the wrong advice given to you on needing an HGV licence. If you have passed your car driving test before Jan 97, and are not restricted by any reportable medical condition, you will have a category C1 on your licence. This permits you to drive a vehicle up to a MAM of 7,500kg, towing a trailer not exceeding 750kg, a total weight of 8,250kg. >>See here for licence categories<<, then scroll down to C1.
If you passed your car driving test after Jan 97, and not taken an additional test, you are restricted to a MAM of 3,500kg.

HTH,

Jock.


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## CaptainBligh (Jan 18, 2008)

Hi Longdistancerunner,

I've had my Hymer B644 replated by SV Tech to 3950kg but the axle weights remained the same.

Happy Travelling Captain Bligh :brave:


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## JeanLuc (Jan 13, 2007)

Your B644 looks about the same vintage as my B630, so I will refer to documents that I have (a Hymer UK catalogue and the generic Hymer instruction manual).

The B644 was built on a Ducato 18 (heavy) chassis with a MAM of 3,900 kg as standard, unless the original purchaser asked for it to be down-plated to 3,500 kg. Your plate will confirm (mine is just in front of the rear UK-offside wheel). The MIRO (which includes 75 kg person, full fuel, water and gas, and EHU lead) is stated as 3,180 kg; but the catalogue states this is an approximate value to allow for manufacturing tolerances.
However, that is for the basic vehicle. If yours has a 2.8 JTD, rather than the standard 2.3 engine, this adds 35 kg to the MIRO, and an awning (3.5 metre) adds another 32 kg. A tow-bar will 'cost' you another 25-30 kg. You may have other options fitted such as a second leisure battery, sat dish, L-shaped lounge instead of dinette (24 kg) etc. You will have to take these into account.

So, from the above, your MIRO could well be around 3,300 kg, leaving a usable pay-load of 600 kg (assuming your van was not down-plated to 3,500 kg).

The maximum possible loading for the garage is stated as 350 kg, but this is the limit that can be carried by the rear chassis extensions and structure that support the garage. The maximum rear axle loading will almost certainly reduce that figure in practice.

Weight distribution is the key issue and as you may have suspected, there is no real substitute for loading everything on-board and visiting a weigh-bridge. Then adjust the loading until you get within your axle limits. You will then have a pretty good idea of what can be carried and where, and how much tolerance you have for cases of wine on the return home!

Philip


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