Up weighting - air anyone ? what did you have and whats the best bang for buck ? (1 Viewer)

[Hoovie]

.....
Springs. The light standard springs are hopeless on a heavy hector like autotrails and so need something for sure. My Bolero came with uprated springs to plated 3850 and stood up at the rear a lot, and nothing i ever loaded in that van ever even dropped it by an inch, as i say, the Bolero is a light van, the autotrail 634 is anything but, and sat down at the back even when empty. Hence this original post enquiry. I have a feeling this question will run and run.

Your comment on the Autotrail 634 sat down even when empty is interesting, as I would think your Apache 634 and my Cheyenne 635, both at 3500Kg would have near identical weight distribution.
But where as yours is flat on the springs, mine is anything but (as can be seen by the photo posted to illustrate) and pretty well echos your experience with the Bolero with its uprated springs, even when loaded close to capacity on the rear axle.
The springs were updated before my ownership - and replaced from the standard due to a breakage. And the previous owner decided to avoid a repeat by going for the VHD triple-spring (from Jones Springs, if interested?). I have not come across anyone who has the VHD springs fitted let alone airbag/spring uprate combo.

.... i do know for sure tyre pressures have a huge effect on handling and comfort. 80psi is waaay too hard no matter what anybody says. but depending on your vehicle and load i suggest to try 60 psi front and 70 psi rear and experiment - less than those will make your van a wallowing old hector unless you have a light load.
you need tyres that can carry a heavy load AND heavy sidewalls made for motorhomes as although commercial tyres can take the load, they will go oval soon as motorhomes stand still alot way before they wear out.

Pressures and "Motorhome" tyres are a tricky one.
As most know, If you run Michelin Aglis CP Camping Tyres, they only have one permitted rear pressure - 80PSI. Much higher than other tyres (including their other Aglis ones) would be specified at. The Aglis Camping tyre does have a different construction, so maybe that 80PSI stipulation IS required as a feature of safely running the tyre and trumps other desires? Something to consider as there must be a reason why they demand 80PSI on that tyre and not their others?
I recently did a check (using Tyresafe I think?) on pressures after my weight uprate and I am set at 67PSI rears and 56PSI fronts on my Michelin Aglis Tyres - however I am not running the CP Campers, but the C Cross-Climates due to wanting better all-season & colder temperature ability than the Summer focussed Campers.
I try to drive my Motorhome on a weekly basis however rather than being stored and stationary for months though.

AIRBAGS. i have tried a few pressures and again no hard and fast rule. but high pressure such as above 30psi will do little except turn it into a boneshaker and brutal over bumps and level crossings ect. and will have the same effect as hard pressured tyres., I have yet to concisely prove springs or air is better as there are no constants., and of course MANY opinions..

I think your above comment mirrors my experience to a fair degree. Because the Uprated Springs increased the gap from the bump stop position to the axle, by the time you have inflated the airbag enough for it to have any compression resistance (if that makes sense), the pressure it will be set is probably too high to provide that compliance and control that the airbag is meant to provide.
The airbag clearly can have some advantages over an uprated spring, being adjustable. My previous camper was a 4.6t Minibus I converted, with the suspension fitted accordingly as standard. When the van was stripped out ready to start the conversion, the ride was incredibly bouncy due to so little weight at the rear.


I would not recommend Airbags for anyone who already has VHD uprated springs simply as it does little as normally installed. I guess you could have some kind of block added to the Airbag so that it starts to take effect at a lower pressure? That could have a good effect thinking about it, but could well change other characteristics and not a project to be undertaken lightly.
I spoke to VB Suspension about the combination of Uprated Springs and their Air Assist system before I installed it and they couldn't really comment as had no experience of using the two togethr either.

I would need to drive a similar motorhome to mine, but fitted with Airbags and standard spring to know the answer vis-a-vis Airbags vs VHD Springs (maybe we need to try a drive in each others motorhomes? )

If I needed to get extra assistance at the rear and had to chose between Air Assist or Uprated Springs, I would go Air Assist if I was also wanting to get a weight uprate - so that decision based on getting the right paperwork more than anything else.
If I didn't need a weight uprate, I think it is much less clear-cut. Springs are the more agricultural but cheaper and more reliable solution for sure, but the techie in me likes the idea of adjustable rear air suspension (which is why I was disappointed at the end result on my own van).

So a lot of words to say "no, I don't know either"

 

[roadwarrior]

OK, SO .. a few points , the bump stops that came with our autotral isnt a bump stop, its actually supposed to play a part and its quite normal to see the spring sitting on the "bumpstop" and its job is to partially take some of the load.
The 80psi on our mh tyres is a MAXIMUM and definately not a recommended or heaven forbid a compulsary pressure - i repeat it is the very MAXIMUM the tyre is capable of withstanding, and remember.... 80psi cold could be 85psi hot.
I say again - depending on your load and personal preferances ie hard or comfortable. the fronts can be from 60psi -70 and rears 65 -75 - in my 634 i run 60/70psi - less will make it roll more but comfortable over bumps - more will make a more firm ride - its your choice.
In many ways we seem to be on our own unlike say cars, which have infinate information on every subject. But we are left to guess with motorhomes in many areas such as this. Hoovie, I think your situation was a prime example of the mushroom situation with motorhomes ( kept in the dark and fed.....) there is no way you should have had to get air assist with those springs you have. There should have been documentation with those springs to prove weight capabilities .
It rather puts me in mind of my first - and elderly autotrail - i went down to a spring manufacturer in coleshill nr birmingham and i did the same - i bought a duel uprated spring set and the result was startling to say the least - it stood so high it was embarrassing - and i asked them to remove one of the leaves . It was a long time ago now but i cant imagine what its capability would have been. assuming your riding high then yes i think the air bags in your case will never see use or need. Did you say you have a 634 like me ? I think like you im curious for comparison - i feel a meet coming on ..

 

[Hoovie]

ref the 80PSI ... as far as Michelin is concerned, it is not just a recommendation but a requirement. Not saying I agree with it, but that IS the stance from Michelin.
"Bumpstop" ... just using the shorthand term

I would agree about should not have had to be forced down the road of Air Assist, but that was the situation. In the same way I spoke to VB Suspension about the situation, I also discussed with Jones Springs (the makers) on this subject and they said (just like with the official specs on the Air Assist) there were 3500 rated only on that installation. So nothing I could do. But I do do my research
It is a bit like Rock & Roll beds fitted on many VW Camper Conversions... the cost of the approvals is so high, the companies producing the products are either not in the position or do not have enough reason to get officially certified on the various combinations even though they would almost certainly pass without a problem. A shame.

I have a 635. There is a Cheyenne 634 and the difference I think is layout? weights, etc are the same. I'll be in the Midlands for a week for so from next weekend

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[roadwarrior]

annoying i have too much on for a week or so, where are you normally ? im sure a micromeet is doable and a test route .... i think sitting as a passenger would be as good if not better as we would be free to observe without worrying about bending someones pride and joy as we concentrate on bumps and rolls and the ultimate ride

 

[Howard B]

ref the 80PSI ... as far as Michelin is concerned, it is not just a recommendation but a requirement. Not saying I agree with it, but that IS the stance from Michelin.
"Bumpstop" ... just using the shorthand term

Michelin Tech support recommended I run at 80PSi rear and 65PSI front for my Adria Twin.
I needed to fit 16" wheels as well as air assist to uprate to 3850kg.

 

[Hoovie]

annoying i have too much on for a week or so, where are you normally ? im sure a micromeet is doable and a test route .... i think sitting as a passenger would be as good if not better as we would be free to observe without worrying about bending someones pride and joy as we concentrate on bumps and rolls and the ultimate ride

I was thinking evaluate as Passenger is better as well
I'm based in Scotland but next few weeks in Malvern (Busfest), then Stratford (Overland Show) and then Berkshire via probably Somerset before heading home via Yorkshire.

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[Hoovie]

Michelin Tech support recommended I run at 80PSi rear and 65PSI front for my Adria Twin.
I needed to fit 16" wheels as well as air assist to uprate to 3850kg.

The 225/70/15 inch tyres with a 112 load rating are good for the 3850Kg uprate.
(that is the route I took and even though I bought new Wheels when I changed Tyres, I went for 15" ones rather than changing to 16" to get a fatter profile).

 

[Howard B]

The 225/70/15 inch tyres with a 112 load rating are good for the 3850Kg uprate.
(that is the route I took and even though I bought new Wheels when I changed Tyres, I went for 15" ones rather than changing to 16" to get a fatter profile).

I couldn't find anyone local willing to put the 225 tyres on the 15” rims . Plus it only cost me £300 to fit 16” fiat wheels with almost new tyres which was cheaper than going with the wider 15” tyres.

 

[Hoovie]

I couldn't find anyone local willing to put the 225 tyres on the 15” rims . Plus it only cost me £300 to fit 16” fiat wheels with almost new tyres which was cheaper than going with the wider 15” tyres.

ah - maybe the wheel width of the standard steel 15" wheels are a bit narrow? I got 15" alloys when I changed which would be wider.

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[Lenny HB]

I changed to 225 on 15" standard Fiat steel rims on the last van, no problems.

 

[roadwarrior]

I was thinking evaluate as Passenger is better as well
I'm based in Scotland but next few weeks in Malvern (Busfest), then Stratford (Overland Show) and then Berkshire via probably Somerset before heading home via Yorkshire.

I will try sort something before you bugger off back up north then