Air Ride Suspension

[bob b]

I received my Dunlop kit last week & I'll fit it tomorrow. Upon leafing through the enclosed literature I discover that, as I'm fitting it myself, I don't have the manufacturers (Dunlop) guarantee.

The enclosed warranty form requires the place and date of installation and also the company stamp and signature of the installer. As its hardly 'rocket science' to fit the things, I think its a bit of a cheek.

[Patricia]

Had Air-Rides fitted some years ago by Simonspeed and they are great. I keep them inflated to about 40 which seems right for this m/home (Cheyenne 635). They make a great difference to stability.

 

I have only read this thread very quickly but notice that no-one has mentioned insurance or guarantee inplications of the other methods. I know Simonspeed assured us that there would be no complications in this respect.

[bob b]

I'm just hoping to get a more comfortable ride. I get the most dreadful 'jarring' when the leaf springs meet the bump stops.

[Keithl]

bob b - 2010-08-02 9:35 PM

 

I received my Dunlop kit last week & I'll fit it tomorrow. Upon leafing through the enclosed literature I discover that, as I'm fitting it myself, I don't have the manufacturers (Dunlop) guarantee.

The enclosed warranty form requires the place and date of installation and also the company stamp and signature of the installer. As its hardly 'rocket science' to fit the things, I think its a bit of a cheek.

 

Bob,

 

You can get the Dunlop warranty simply by completing and signing the declaration in your own name and then sending it back to Dunlop.

I phoned them and got an email address to send it back to as I found that easier.

 

I fitted the Dunlop system (from Marcle leisure) to our Merc based AT a few weeks ago and have just done over 800 miles and the difference is unbelievable. I am currently running at 40 psi (2.75 bar) and this has lifted the rear, measured at the rear wheelarch, by 1 inch.

I think the second most noticeable thing, after the improved resistance to buffeting, is the fact that the back end does not bottom out anywhere near as much as before. In fact I think it would be extremely difficult to get it to bottom out at all now.

 

If anyone is in any doubt about getting a system fitted then all I can say from my experience is I do not think you will regret it!

 

Keith.

[Keithl]

Patricia - 2010-08-02 10:05 PM

I have only read this thread very quickly but notice that no-one has mentioned insurance or guarantee inplications of the other methods. I know Simonspeed assured us that there would be no complications in this respect.

 

I've just read Patricia's note on insurance and can confirm that I contacted our insurers before ordering a system and they quoted to me in writing that there would not be any alteration to the premium and now after fitting I have it, again in writing, that they are aware of the modification to the suspension with no implications to the policy.

 

I would strongly suggest anyone else fitting a system does the same.

 

Keith.

[bob b]

Hi Keith,

            Is the e mail address info@dunlopsystems.nl ? Otherwise the form has to be posted to Holland.

I have fitted the kit and agree it does make a difference to the ride and handling. I had to re-route the waste pipework from the shower as it interfered with one of the units. Apart from that,  fitting the kit was really quite straightforward.

[Keithl]

Bob,

 

PM sent.

 

Keith.

[dwaviation]

Just to jump in at the end. I have just replaced both rear springs due to one of them cracking around the rear hangar (£200 each....) and we fitted Dunlop Airride at the same time. Wow! what a difference. We would bottom out all the time before and send everything at the back crashing all over the place. Now it's like being on a luxury yacht with stabilisers deployed - Fantastic!

[Brian Kirby]

You don't say what you van is but, if the rear was bottoming that badly, are you sure the rear axle isn't in overload?

[rapidoman]

we spent several years suffering bumpy and bad handling on rough roads as well as bottoming out on a brand new van, at th time dealer and manufacturer said it was normal (?) eventualy fitted airide WHAT a difference much more comfortable and better handling, also added advantage of being able to raise it if needed to go on ferries or help leveling. have since changed van now have alko chassis which seems to be far superior to fiats own *-)

[dwaviation]

Brian Kirby - 2010-08-07 12:03 AM

 

You don't say what you van is but, if the rear was bottoming that badly, are you sure the rear axle isn't in overload?

 

My van is a little Autoquest 115 (stop giggling at the back) and from new my springs were nearly touching the stops so it didn't take much to make things go 'crash'. Rear axle limit was never exceeded and when loaded the van was level front to rear - since the new springs have been fitted we are most definitely 'tail up'... our Airride is set to 0.5bar (minimum setting)

[Brian Kirby]

The 2020 version has an MAM of 3,000kg (front axle 1,600, rear axle 1,650), and its an end kitchen (an so much of the weight) design with the entrance door behind the rear wheels, so a longish rear overhang, making it quite sensitive to rear loading.

Maybe the spring was a dud but, if the van wasn't new when you got it, from what you say about the condition of the old rear springs compared to the new ones, they do seem to have had a rather hard earlier life.

I think I'd be inclined to experiment with a bit more pressure in the air rides to see how that works out.  One thing I have noticed is that as the air ride units take more of the load, the rear suspension becomes smoother over minor road irregularities.  Not potholes, but those dropped manholes and drain covers, poor patches, etc, that litter our roads down here.  I think this is because as the the air units are inflated they gradually lift the rear of the van, relaxing the springs a bit, and so taking more of the load themselves.  Being inherently softer, they then seem to absorb these smaller vertical axle movements with less "thump" than the springs alone can achieve.  At least, that's my theory!  :-)

[Keithl]

Brian,

 

I'll agree with your theory on the air springs absorbing the bumps better and they certainly do seem to make for a better ride.

 

As for only running at 0.5 bar then this is the minimum pressure to prevent them from getting damaged and will offer very little, if any, assistance.

 

The Dunlop instructions say that "the air helper springs will support approximately 30 lbs of load for each psi of inflation (per pair). For example 50 psi of inflation will support 1000 lbs per pair". (Yes I do know the figures don't quite add up).

Using this calculation then 0.5 bar (approx 7 psi) will only be supporting around 200 lbs (or less than 100 kg in modern measurement). This is a mere fraction of your rear axle load and hence will in reality be doing nothing! I suggest you try increasing the pressure to 30 or maybe 40 psi and see what the difference is. Note that the maximum permitted pressure in these systems is normally 100 psi so do not be afraid of running at 30 to 40 psi.

 

Keith.

[dwaviation]

Thanks for the advice chaps, I'll pump them up a bit, problem is I don't want to lift the rear end up too high... It already looks faintly ridiculous! Truth is I only fitted the airride to upgrade the rear axle to 1750kgs! I guess the new springs are coping admirably on their own.