Derek Uzzell Posted November 7, 2018 Share Posted November 7, 2018 Robbo - 2018-11-07 3:28 PM ...I'm a bit confused with regard to Derek's recent post referring to a permissible rear axle load of 2200kg. You state that your permissible rear axle load is 2000kg as per your original Dethleff plate... My mistake - I misread the rear-axle datum in Steve’s posting as 2200kg, not “axle 2 2000kg”. It’s still the case though that, if the axle 1 (ie the front-axle) now has a lmaximum load-limit of 1850kg, 100kg has been ‘lost' from the 1950kg shown on the Dethleffs data-plate. Link to comment Share on other sites More sharing options...
Sssnake Posted November 7, 2018 Author Share Posted November 7, 2018 Derek, The new VIN from JR Consultancy records exactly the identical weights for front and rear axles and MPTLM as Fiat’s original so I don’t believe that I need to keep Schtum about anything? Fiat - axle 1 1850 axle 2 2000 MPTLM 3850 Dethleffs - axle 1 1950 axle 2 2000 MPTLM 3499 Link to comment Share on other sites More sharing options...
Derek Uzzell Posted November 8, 2018 Share Posted November 8, 2018 Steve In your earlier postings you said that your motorhome’s VIN-plates provided the following details Fiat MTPLM - 3650kg Axle 1 (front axle) 1850kg Axle 2 (rear axle) 2000kg Dethleffs MTPLM - 3499kg Axle 1 (front axle) 1950kg Axle 2 (rear axle) 2000kg As I understand it, what you now have is JR Consultancy MTPLM - 3850kg Axle 1 (front axle) 1850kg Axle 2 (rear axle) 2000kg and, if that’s correct, then the Dethleffs Axle 1 (front axle) maximum of 1950kg has reduced by 100kg to 1850kg and the vehicle’s MTPLM has increased from the Dethleff’s figure of 3499kg to 3850kg. Fiat does not offer a Ducato ‘light’ camping-car chassis with a MTPLM above 3650kg, although a motorhome manufacturer may offer an above-3650kg MTPLM for a motohome built on that chassis. You don’t NEED to keep quiet about your motorhome’s increased MTPLM, but Fiat won’t authorise that increase. If there were a problem with, say, your motorhome’s braking system while the vehicle is under warranty, Fiat MIGHT argue that an unauthorised increase in the MTPLM was a contributory factor. (This is a very hypothetical scenario, but if you think that Fiat would authorise increasing the weight-related values on their VIN-plate, you’d be best to confirm that with them...) When uprating a motorhome’s weight maxima has been discussed here in the past, it’s been regularly emphasised that merely increasing the vehicle’s MTPLM may not address a potential overloading problem, for (as Robbo highlights) it’s often difficult to transfer weight from the most heavily loaded axle to the more lightly loaded axle so that the increased MTPLM can be usefully exploited. Your original objective was to increase your motorhome’s MTPLM of 3500kg "without paying a company like SV Tech and do it myself” and the MTPLM increase to 3850kg has been achieved at a cost of £180 using the services of JR Consultancy. But this exercise has not increased the original rear-axle maximum of 2000kg and that’s where the potential overloading risk lies. With hindsight you might have been better exploring the SVTech route, as I suspect that they would have offered you an increase in the rear-axle weight-maximum as well as an uprated MTPLM. SVTech’s normal policy in such an instance is to advise a requirement for tyres with an appropriate load-index to cope with the raised rear-axle weight-maximum (Your motorhome already has such tyres) plus the fitting of a ’semi-air’ kit to beef up the rear springing. Was a rear-axle weight-maximum increase discussed with JR Consultancy? Link to comment Share on other sites More sharing options...
Robbo Posted November 8, 2018 Share Posted November 8, 2018 I belong to a MH owners club. We regularly receive requests for advice concerning upgrade from 3500kg MAM to allow full utilisation of the MH garage. Some owners enquire retrospectively, having already used the paper upgrade method from 3500kg to 3850kg MAM. The latter group are always dissatisfied with the resulting overall usable loading capacity. Not surprising really, because the fresh water tank, waste tank and most of the heavy items (fridge, kitchen storage cupboards) are close to or behind the rear axle. And of course, the permissable axle loads stay the same as the 3500kg MAM chassis. Their problems are compounded by the fact that their vans are based on the AL-CO chassis which costs £2k+ to increase the load capacity of the rear axle using semi-air suspension. Returning to the thread, it's worth mentioning that J R Consultancy was only mentioned by Derek for the paper upgrade from 3500kg to 3650kg. For this basic upgrade, they would have undoubtedly been cheaper than SV Tech. It would be interesting to learn whether J R Consultancy offered Steve an enhancement to the rear axle load as mentioned by Derek in his latest post. Link to comment Share on other sites More sharing options...
Steve928 Posted November 9, 2018 Share Posted November 9, 2018 Derek Uzzell - 2018-11-08 9:15 AM With hindsight you might have been better exploring the SVTech route, as I suspect that they would have offered you an increase in the rear-axle weight-maximum as well as an uprated MTPLM. SVTech’s normal policy in such an instance is to advise a requirement for tyres with an appropriate load-index to cope with the raised rear-axle weight-maximum (Your motorhome already has such tyres) plus the fitting of a ’semi-air’ kit to beef up the rear springing. Was a rear-axle weight-maximum increase discussed with JR Consultancy? Just for information, JR has authorised an upgrade of the light chassis (albeit the Al-Ko version) to 4100kg for several Bailey owners, by fitting 112 load-rated rear tyres and semi-air suspension on the rear only. The axle maxima are then 1850 front and 2240 rear. Someone such as yourself, Derek, will quickly spot the 10kg discrepancy between the axle maxima and the MTPLM, but this (nor running tyres at 100% of their load capacity) doesn't seem to bother either JR or DVLA and these upgrades have been approved and plated as such.. Personally I think that for anything other than the routine paper upgrades SV Tech are the more competent engineering authority. Link to comment Share on other sites More sharing options...
Derek Uzzell Posted November 9, 2018 Share Posted November 9, 2018 As it was supplied with 16”-diameter steel wheels I’d expect the load-index of the tyres on Steve’s Dethleffs motorhome to be 116 (2500kg maximum axle-load) or 118 (2640 maximum axle-load) so an increase in the vehicle’s original (and current) rear-axle maximum loading of 2000k to (say) 2200kg would not be limited by the present tyres. The DVLA seems more interested in the MTPLM (presumably because it relates to VED) than axle-loading values, so it might be worth Steve talking to JR Consultancy to see whether - if he were to fit a semi-air kit to the rear axle - they could just issue him with a revised ‘sticker’ showing a higher rear-axle maximum. Can’t say I much like the idea of taking the MTPLM of a ‘light’ Ducato’s chassis to 4100kg. That weight is in ‘heavy’ chassis territory and ‘heavy’ chassis have bigger brakes. Link to comment Share on other sites More sharing options...
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