Losing my fillings...

chenderson1965

Free Member
Joined
Aug 3, 2019
Posts
327
Likes collected
274
Location
Nottingham
Funster No
62,953
MH
N+B Arto 79R A Class
Exp
10 years with hires, Newbie owner
We love our Arto (79R 2012, Ducato 3L). It does pretty much everything we needed to do.

The one thing we love about it a little less is the very firm suspension. It’s absolutely fine on smooth roads but as soon as the road surface deteriorates, the suspension feels bone jarringly firm. Apart from the vibration, we also get a fair amount of rattling and creaking – which all makes the experience of driving much less relaxing.

We’ve been through and done all the obvious things like anti-slip matting and eliminating everything that might rattle because it’s loose. My question is whether there’s anything we can do to take the edge off the firmness of the suspension.

We have the tyres pumped to manufacturers recommended pressures - 80 psi on the front and 56 on the (tag axle) rears. I guess we could try it with slightly lower tyre pressures but I’m reluctant to go against what the handbook says.

Does anybody have any other ideas?

I’m even wondering whether it might be worth investigating an upgrade to air suspension. Does anyone know an approximate cost for this or who might be good installers (we are based in Nottingham)?

Thanks a lot

Chris
 
Play with the tyre pressures.
 
80 psi on the front sounds far too high, 60 to 65 psi to would be more normal.

Our van had a very hard ride we had full air suspension fitted probably your best option to improve the ride.
 
Ditto what Andy say's 80psi does sound a tad high for the front, certainly would be for a coach built. I know your's is an A class for which I havle very little knowledge especially the tyre pressures. Again not sure if it's feasible for an A class (I assume it's more than 3850kgs) but have you considered air assist on the rear axle

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80 psi on the front sounds far too high, 60 to 65 psi to would be more normal.

Our van had a very hard ride we had full air suspension fitted probably your best option to improve the ride.
Thanks. Sounds like some research to do on axle weights and tyre pressures first before thinking about writing a big cheque.

do you mind me asking how much your air suspension conversion cost?
 
Check Tyresafe website for pressures. I dropped mine to 4.3 bar instead of the Fiat recommended 5.5. Made a huge difference.
 
Manufacturer of Moho and tyres probably says 80psi all round so unless they can confirm in writing otherwise you may need to stick at that. Simple solution is not to drive very far in the UK and use good quality roads throughout Europe 😂😂
 
Thanks. Sounds like some research to do on axle weights and tyre pressures first before thinking about writing a big cheque.

do you mind me asking how much your air suspension conversion cost?
I have the Goldschmidt Full Air (V B wasn't suitable for my van) I paid £7,150 had it fitted in Belgium UK agents Travelworld wanted £8,700. VB is only £6,600.
 
Two opposing thoughts not mentioned. Are you running fully loaded and your suspension is reaching its limits alternately, is your suspension carrying enough load to activate it effectively.
Air suspension on two vans I have owned made the ride a little harder but better.

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We have had 4 tag vans 55 in the rear and 65 in the front found it worked for us 👍
 
I set 60 all round in our E510 and it's really nice now. Reduced from 80 odd ! The tyres do not get warm and the harshness is virtually gone. We have AirRide as well set at 35psi.
 
Try 70 all round, you will notice the difference
Why go up on the rears? it's a tandem axle so thought it wouldn't need to be too high.

I do think we need weights and tyre details but my first reaction would certainly be too high on the front, I don't even run 80 psi on ours at 2500kg on the front axle,

M

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Hmmm. So I contacted Michelin (via LiveChat) and got this reply. (They did not ask for axle weights)

The recommended tyre pressure for the rear (single) axle of a motorhome running on the MICHELIN Agilis Camping is 80 PSI (5,5bar) and for twin axle 69PSI (4,75bar)
This is due to the construction of the tyre with 2 casing plies enabling the use of higher pressures.
The front tyres however can be adjusted down to a pressure of 65 PSI for a more comfortable ride and optimum performance.

I also took my axle weights/trye details and put them into the calculator on Motorhome Tyresafe and it produced results of 59psi front and 44 rear.

Looks like they can come down to at least 65 Front (Michelin recommendation) and leave the rears at 55 (N+B recommendation). I'll try that and maybe even experiment with 5 psi less than that in both (Tyresafe recommendation) if still not happy.
 
I’m sure an adult will be along soon. But 80psi on the front is far higher than I would run.
me too crazy pressure i run at 65psi and still have my fillings
 
Only a PVC but contacted Bridgestone with actual axle weights in travelling trim - 53psi front & rear - was surprised the recommendation was so low but had it confirmed via another source.
80psi must be bone shatteringly harsh.
 
In our 4.8 ton Arto we have 51psi front and 76 psi rear
These pressures are based on our actual axle weights and Continentals suggested pressures for Vanco Camper tyres

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Thanks. 2000kg front and 1500 rear (twin axle).
Are those the actual weights measured on a weighbridge? I suspect they are the max weights which isn't really relevant if you take it to the weighbridge fully loaded for touring. :)
 
Thanks. 2000kg front and 1500 rear (twin axle).
Are those the actual weights measured on a weighbridge? I suspect they are the max weights which isn't really relevant if you take it to the weighbridge fully loaded for touring. :)
Notwithstanding John's comments, if the weight's quoted are actual weights...

Chenderson.jpg


64psi for the fronts, 38psi for the rear set - not a million miles away from your Tyresafe figures - but lightyears from what you're running now.

Next question... what is the load index of your Michelin's.

And in answer to your original question - tyre choice might be a more cost effective option than rushing to fit extra toys...

It's obvious that from a few authoritative sources & personal experiences, lowering the pressures might solve your issues - so it makes sense to try that first.
 
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Are those the actual weights measured on a weighbridge? I suspect they are the max weights which isn't really relevant if you take it to the weighbridge fully loaded for touring. :)
No. Those are the plated maximum figures - which were what the other calculator I used asked for. I haven’t been to a weighbridge yet so don’t have actuals.
 
No. Those are the plated maximum figures - which were what the other calculator I used asked for. I haven’t been to a weighbridge yet so don’t have actuals.
Assuming you aren't overweight (the MH not you!) then you should be safe using those figures but potentially you might be able to go lower still but only if you switch to Continental tyres as they are the only manufacturer I think who gives very specific recommendations based on axle weight.

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Our Rienza runs on Continentals. 65 psi rear, 55 psi front. It is a firm ride but not unbearable and it handles well for its size.
Whilst training on a Renault recovery vehicle my instructor said I am glad it’s a Renault not an Iveco. You need to invest in chewing gum to keep you’re teeth apart on the Iveco. The Renault had air suspension not leaf springs as per the Iveco.
 
Assuming you aren't overweight (the MH not you!) then you should be safe using those figures but potentially you might be able to go lower still but only if you switch to Continental tyres as they are the only manufacturer I think who gives very specific recommendations based on axle weight.
Took some research to find the guy - but Bridgestone also gave me specific recommendations
 
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Notwithstanding John's comments, if the weight's quoted are actual weights...

View attachment 423726

64psi for the fronts, 38psi for the rear set - not a million miles away from your Tyresafe figures - but lightyears from what you're running now.

Next question... what is the load index of your Michelin's.

And in answer to your original question - tyre choice might be a more cost effective option than rushing to fit extra toys...

It's obvious that from a few authoritative sources & personal experiences, lowering the pressures might solve your issues - so it makes sense to try that first.
Thanks. Not sure which number that is but they are Agilis 225/75 R16 116Q.
 
My Aclass 4t with Continental 4 seasons, front 52psi rear 69psi (Mercedes rear wheel drive) as recommended by continental
 
Thanks. Not sure which number that is but they are Agilis 225/75 R16 116Q.
Looks like the load rating is 116 - so the spreadsheet is accurate.
Can be tweaked if you get actual weights.

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