scotchjock Posted August 21, 2007 Share Posted August 21, 2007 I was thinking about adding a sat dish, tow bar, and air assistance to the suspension on my 2007 Hymer T686SL. While on holiday I saw a public weighbridge, thought better just check. Oh! oh! 160kg overweight with very few personal items on board. On checking the unladen weight I realised that upgrade items i.e. wind out awning, TV, high gain aerial, bigger fridge/freezer with oven, microwave, were all part of the payload. Solution: uprate to 3850kg with air suspension to replace existing leaf springs. This will allow rear overhang to be raised when boarding ferries etc. Link to comment Share on other sites More sharing options...
BGD Posted August 21, 2007 Share Posted August 21, 2007 Hi Jock - I may not get this quite right (others here are far more experienced in such matters), but I don't think that legally you can do that. (Doesn't mean you can't of course, but you could get trouble if the Police weigh you). I think the max loading on an axle is exactly what it says...the maximum weight that you can have on that axle. It doesn't matter if you uprate the springs, that doesn't increase the plated maximum permissable axle weight. Do others agree, of have I misunderstood the regulations on this? Cheers, Bruce. Link to comment Share on other sites More sharing options...
scotchjock Posted August 21, 2007 Author Share Posted August 21, 2007 The vehicle will be replated to show new max GVW by the specialist company carring out the upgrade Link to comment Share on other sites More sharing options...
Guest JudgeMental Posted August 21, 2007 Share Posted August 21, 2007 The weight can be upgraded if chassis has the capacity. but I think Bruce is correct as nothing can be done regards rear axle - did you weigh your rear axle? if yes, and no spare capacity I believe you are wasting your time. Derek! where are you when we need you! :-D edit: just reread your post. have heard of upgrade with air suspension being possible on some chassis. but axle capacity is still critical IMO... better off buying correct vehicle for your needs in the first place. *-) Link to comment Share on other sites More sharing options...
scotchjock Posted August 21, 2007 Author Share Posted August 21, 2007 The vehicle in question is a Renault Master which is available as 3500 or 3900kg. Renault supply full air suspension on the 3900kg version on the same chassis. As a novice motorhomer, I thought that 390kg payload would suit our needs as a couple. What I was not aware of was the extras were taking up payload. The fact that I saved £10,000 by importing goes some way to compensating for my mistake. To clarify on air suspension: Air assisted suspension retains the existing springs therefore increases vehicle weight. Full air suspension replaces the springs and is lighter, giving a more stable ride. Link to comment Share on other sites More sharing options...
Mel B Posted August 21, 2007 Share Posted August 21, 2007 I understand about the leaf springs weight being deducted and replaced by the full air suspension so that it is not additional to the leaf springs. But what is your actual rear axle weight and also what is the maximum permissible rear axle weight? It is still necessary to make sure you are not over it the maximum rear axle weight, even if the whole vehicle is under the MTPLM. I think that makes sense. Link to comment Share on other sites More sharing options...
robin Posted August 21, 2007 Share Posted August 21, 2007 scotchjock - 2007-08-21 4:31 PM The vehicle in question is a Renault Master which is available as 3500 or 3900kg. Renault supply full air suspension on the 3900kg version on the same chassis. As a novice motorhomer, I thought that 390kg payload would suit our needs as a couple. What I was not aware of was the extras were taking up payload. The fact that I saved £10,000 by importing goes some way to compensating for my mistake. To clarify on air suspension: Air assisted suspension retains the existing springs therefore increases vehicle weight. Full air suspension replaces the springs and is lighter, giving a more stable ride. I have a Renault Master plated at 3500k - As I understand it,(?) there are no modifications required to have it replated to 3900k. The Master is supplied with the same tyre size and other suspension gubbins whether plated at 3500 or 3900. The max axles weights on my 'van are quoted as 1850k front, and 2050k rear which spookily adds up to 3900k - if you plate your 'van up to 3900 you will have to load it pretty carefully if you are running near the limit to avoid overloading any axle. As I said, this is my understanding, which is quite likely to be wrong. I also do not know how the air-springs change things - I would be surprised if they increase the allowable rear axle load - as you say I would have thought that they just improve the ride and handling. I hope that the experts on this can clarify. Link to comment Share on other sites More sharing options...
scotchjock Posted August 21, 2007 Author Share Posted August 21, 2007 I am awaiting replies from Renault UK and TVAC with final details on upgrading GVW. I will post info when I get it Link to comment Share on other sites More sharing options...
scotchjock Posted August 26, 2007 Author Share Posted August 26, 2007 Spoke to helpful person at TVAC who said after checking that the current Renault Master can be replated to 3900kg without any modification other than changing the loading plate. I'm still waiting for Renault UK to clarify further Link to comment Share on other sites More sharing options...
Guest JudgeMental Posted August 26, 2007 Share Posted August 26, 2007 That looks OK as long as happy with restrictions and extra cost of being over 3500kg while traveling abroad. When looking for a van, I found most low roof models came in around 2900-3000kg including driver etc.. Leaving a reasonable 500-600 kg payload. take of 150kg for extras this still leaves 350-450kg. we manage to stay just about legal with four of us and a hightop van. Just a bit puzzled by your hymer... Link to comment Share on other sites More sharing options...
Brian Kirby Posted August 26, 2007 Share Posted August 26, 2007 scotchjock - 2007-08-26 8:32 AM Spoke to helpful person at TVAC who said after checking that the current Renault Master can be replated to 3900kg without any modification other than changing the loading plate. I'm still waiting for Renault UK to clarify further RoyWhat you have to watch, as others have said, is the load limit for the individual axles of the Renault. You should, ideally, re-weigh the laden van, noting the front, and especially the rear, axle loads separately. If either axle is already close to (or even above) its plated limit, no amount of re-plating of the van, or adding of air suspension, will help. If you have reasonable spare capacity on both axles, and are very careful how you load the van to stay within the individual axle, and new MAM, limits re-plating should be fine. Air suspension may well assist ride, but if you feel it is needed, I'd suspect you are already near, or above, the plated limit for one of the axles. The payload you are left with is, in reality, pretty well unworkably small. Travelling without water on board - at 1Kg per litre - may be a better solution, but do remember to empty the waste tank at every available opportunity! Link to comment Share on other sites More sharing options...
Derek Uzzell Posted August 27, 2007 Share Posted August 27, 2007 Hymer's 2007 UK brochure advertises a £338 upgrade for the T-SL 686 from 3500kg to 3850kg. This price suggests that the upgrade may be an 'administrative' one rather than there being any technical difference between 3.5t and 3.85t variants, but it would be worth checking this with Hymer(UK). Frankly, for a 3500kg 7.19m motorhome with a brochure-quoted payload of 380kg in basic form, few people would be comfortable operating the vehicle legally at the lower chassis weight limit. Full air rear-suspension is rarely offered on motorhomes and it's not a Hymer option on this model. Even if it's an option on the base-vehicle chassis (as it is with the Master), if it's not shown as an option in a motorhome catalogue there's a strong possibilty it will be impractical to retro-fit it once the motorhome has been completed, as the converter will have made no allowance for it when designing and implementing the conversion. From what I can glean from motorcaravan brochures, the Master seems to have a relatively low rear-axle maximum weight limit even when its maximum overall weight is at 3850kg. As Brian Kirby suggests, it would be wise to check loaded axle-weights. Link to comment Share on other sites More sharing options...
scotchjock Posted August 27, 2007 Author Share Posted August 27, 2007 Thanks guys for your helpful input. The axle limits are 1850kg front, 2050kg rear. My latest weigh in gave 1560kg front and 1860 rear. This was removing one gas bottle, cutting fresh water from 120l to about 50l, and cutting back on uneccesary items that 'her indoors' had accumulated over the last 6 months. Link to comment Share on other sites More sharing options...
Mel B Posted September 15, 2007 Share Posted September 15, 2007 Scotchjock, pleased you're 'underweight'! Solves a lot of problems!!! Message for Mel E On a previous posting you said that you have an excel sheet that helps to calculate the axle loadings when carrying bits and pieces behind the rear axle with a vehicle that has a long overhang. Any chance of a copy please my sweet - I've sent you a PM.:-> Mel B :-D Link to comment Share on other sites More sharing options...
W3526602 Posted September 16, 2007 Share Posted September 16, 2007 Hi, I'm confused by reading the forgoing. I would have assumed that the plated axle weight was a function of stability,(or road tax) and that the axle itself would be capable of carrying much more without bending 8-) From that, stiffening the springs and uprating the brakes should improve the load that can be carried safely. Conversely, softening the springs will decrease the safe payload. And a vehicle that is too light for its springs will tend to bounce round corners. The previous mails seem to indicate that rear axles are not strong enough to support more than their plated weigh, no matter what springs are fitted. Answer? Fit an axle from the heavier vehicle? Thats assuming the chassis is the same, of course. 602 Link to comment Share on other sites More sharing options...
Mel B Posted September 16, 2007 Share Posted September 16, 2007 Its not necessarily that the axle can't take the weight, its that it has been rated at that weight for licencing etc purposes. Our van is plated as 3500kg overall but it will in fact go up to 3850kg if we choose to have it replated as the basic chassis is already built to withstand this type of load, however, some van's chassis may not be able to take more than the plated weight. Don't forget that the brakes and everything else also has to be able to take the extra load. Link to comment Share on other sites More sharing options...
Pentland Posted September 18, 2007 Share Posted September 18, 2007 As you know i had all this trouble with my motorbike in the back...... They checked with Fiat UK and they said along with Rimor if the Airide kit was fitted then the van can leaglly be replated to show a heavier payload on the rear axel. 3850 kg i think it is, they replated the van and the DVLA changed my log book. I now have a super smooth ride, with no wheel arch rubbing had rear axel re- weighed loaded and it was under the specified max weight and the whole van was 120kg under the 3850kg max. If i am wrong about this which everyone keeps saying your still illegal max weights on the rear etc, well i took it back to the dealer and between themselves and Fiat in Portsmouth thats how the fixed my problem? I know i'm driving it but if something happened and i'm in trouble i'll sue them! There my dealer, they should know what there doing, ? Link to comment Share on other sites More sharing options...
scotchjock Posted October 23, 2007 Author Share Posted October 23, 2007 In conclusion, I now have my Hymer/Renault Master re-plated to 3900kg. SV-Tech issued me with a new certificate, and plate to cover the existing one on the side of the vehicle (Cost £200 + Vat). The next step was to apply for a replacement tax disc, enclosing the old disc, insurance certificate, plating certificate and registration document showing the new GVW, to local DVLA office. The local office issued a replacement disc by return of post (or apply in person). DVLA Swansea returned the plating certificate with the amended registration document and refund of over paid tax. Incidently, the new rate has gone down to £165 per year, and the class is now private heavy goods. I realise that care is still needed with axle weights, but with both water tanks, fuel tank, batteries and gas bottles forward of centre, my last weighbridge readings were well under and I still have almost 150kg of spare payload with all tanks full, two bodies, and two dogs on board. Thanks again for all previous comments and advice, I am well pleased with the end result. Link to comment Share on other sites More sharing options...
Hughmer Posted October 23, 2007 Share Posted October 23, 2007 Welcome to the slow lane. Don't forget that you are now subject to +3,500kg UK national speed limits which are 50 mph on single carriageways, - 60 on dual, - and 70 on motorways. Be very aware that when you're abroad you are now a lorry! So when you see a "no lorry overtaking" sign. it means you (or rather us...) The Germs are particularly hot about this. Link to comment Share on other sites More sharing options...
scotchjock Posted October 23, 2007 Author Share Posted October 23, 2007 The speed limits for my vehicle are as they were before the uprate. The unladen weight was in excess of 3040kg. Link to comment Share on other sites More sharing options...
enodreven Posted October 23, 2007 Share Posted October 23, 2007 Hi, I thought I had read somewhere that for vehicles over 3500 or 3850kg they had to be fitted with ABS does anyone know if that is the case ?? Link to comment Share on other sites More sharing options...
Papa Smurf Posted October 23, 2007 Share Posted October 23, 2007 I just hope you have the correct licence to be able to drive a van replated to more than 3.5 tonnes Link to comment Share on other sites More sharing options...
trooper Posted October 24, 2007 Share Posted October 24, 2007 HI Enodrevan, Yes all vehicles manufactured after a certain date over 3500 have to be fitted with ABS I think you will find, Cheers Link to comment Share on other sites More sharing options...
Hughmer Posted October 24, 2007 Share Posted October 24, 2007 scotchjock - 2007-10-23 6:49 PM The speed limits for my vehicle are as they were before the uprate. The unladen weight was in excess of 3040kg. I don't think so. Perhaps Mel Eastbourne is around. He knows the certain facts I'm sure. But as I understand it, - it's not unladen weight, - but max authorised mass or MAM, (it used to be called Gross vehicle weight) that is the figure to work with. Your MAM is over 3,500kg so I think you have to go with those rules. Link to comment Share on other sites More sharing options...
Guest JudgeMental Posted October 24, 2007 Share Posted October 24, 2007 Hughmer - 2007-10-24 7:44 PM scotchjock - 2007-10-23 6:49 PM The speed limits for my vehicle are as they were before the uprate. The unladen weight was in excess of 3040kg. I don't think so. Perhaps Mel Eastbourne is around. He knows the certain facts I'm sure. But as I understand it, - it's not unladen weight, - but max authorised mass or MAM, (it used to be called Gross vehicle weight) that is the figure to work with. Your MAM is over 3,500kg so I think you have to go with those rules. Yes I think hughmer you are correct and Gross weight/plated max is the figure that counts. If you can manage within 3500kg life is far easier - particularly when traveling abroad. Link to comment Share on other sites More sharing options...
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