Ground clearance gains with semi air suspension (1 Viewer)

[Lucky]

Ground clearance is already marginal when accessing my existing drive with a motorhome and my next mh has a longer overhang which will make matters worse.

Rather than hiring somebody else's mh and trying it for size () or bringing in a digger to change my drive, I wonder if semi air suspension might be a solution.

I appreciate we might be talking guestimates but among those that have fitted semi air, how much higher can you raise your rear end?

 

[Conal]

I am also interested in any knowledgeable comments. I am having a tow bar fitted to my 7.9m Autotrail Delaware and worry about grounding on undulating ground or ferry ramps.

 

[Pappy]

I had semi air fitted recently to increase my gross weight. It hasn't made a lot of difference to height at the back, about an inch from original to max air. That is on an AL-KO chassis with torsion bars.

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[Conal]

Pappy, I thought semi-air was adjustable so that it could be raised when needed but at normal height when driving.

 

[Pappy]

Pappy, I thought semi-air was adjustable so that it could be raised when needed but at normal height when driving.

It is but the maximum I can get is about an inch.

 

[ontheroadagain]

I took some measurements when I fitted semi air last year.
With no air - height to wheel arch was 730mm - height to lowest point at rear was 340mm
With 2 Bar pressure - height to wheel arch was 760mm - height to lowest point at rear was 375mm
With 4 Bar pressure - height to wheel arch was 770mm - height to lowest point at rear was 390mm
I currently run ours at 2 Bar.
Hope this is of some help.

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[berni109]

Adjustable between min and max pressure - yes - but which is unlikely to give much lift at the rear(couple of inches) although with a long overhang the effect will be magnified. You will likely need to find one with a permanently attached compressor or else it's going to be a bit of a phaf raising and lowering the pressure.

 

[Conal]

berni109 Thanks, I will check once the tow bar is on in June but I think I will need the kind you suggest. Also thanks to Pappy for ”raising” the issue

 

[Speve]

Had an Autotrail Tracker FB with rear air (Dunlop) max I was able to get was an extra 50mm

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[Landy Andy]

7.2m motorhome. Air assist raises my rear (tow bar) 4inches.

 

[Conal]

Landy Andy can you tell you sold/supplied/fitted this?

 

[Speve]

7.2m motorhome. Air assist raises my rear (tow bar) 4inches.

Is that with full air though our full air on the Hymer will raise a lot more than just rear air assist as you can drop the front and raise the back.

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[Guigsy]

On our van was on the light chassis. Even with nothing in it, it ran quite low and was always touching the bump-stops. I guess the panel van suspension wasn't designed for permanently carrying half a house! Adding semi-air lifted it up a few cm even with nothing in the bellows. Pumping it up gave about 5cm more lift at the wheel arches. Over a long tail, you'd get more.

 

[Landy Andy]

Just rear air assist, and fitted by me.

 

[Speve]

Just rear air assist, and fitted by me

Yes you have a long overhang at the back I can see it will give that bit extra from the axle height

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[Blue Knight]

I took some measurements when I fitted semi air last year.
With no air - height to wheel arch was 730mm - height to lowest point at rear was 340mm
With 2 Bar pressure - height to wheel arch was 760mm - height to lowest point at rear was 375mm
With 4 Bar pressure - height to wheel arch was 770mm - height to lowest point at rear was 390mm
I currently run ours at 2 Bar.
Hope this is of some help.

Those are very useful figures for Lucky but for Conal specifically he won't achieve such good ground clearances because his van is much heavier.

Conal I would expect you to achieve c.30mm extra at the axle-point if you're operating on or close to your maximum chassis weight.

 

[Conal]

Blue Knight we travel quite heavy so over 4t. 30mm - 3cm isn’t much but, as has been mentioned, the important clearance is at the back, about 2m further back from the axle.

 

[IRHP]

I get about 50mm at the rear when I pump mine up to about 6 bar. Max limit is 7 bar. Haven't tried them at that pressure. I have quite a big overhang

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[Bailey58]

I get about 50mm at the rear when I pump mine up to about 6 bar. Max limit is 7 bar. Haven't tried them at that pressure. I have quite a big overhang

Is that you or the van?

 

[Ninjabob]

I had semi air fitted recently to increase my gross weight. It hasn't made a lot of difference to height at the back, about an inch from original to max air. That is on an AL-KO chassis with torsion bars.

VB Comfort Semi Air on the rear of my Bailey (ALKO low chassis with torsion bars) no real increase in height - just correct height when loaded.

 

[HugoBNB]

It depends on your load. At about 3.2 bar on our Ducato chassis it is about 50mm. I will measure it properly next week when I am up and post again.

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[IanF]

7.6 Savannah and can lift rear to access steep ferry ramps by approx 100 mm

 

[IRHP]

Is that you or the van?

Both

 

[huck999]

Just fitted air assist at rear of our Trend. With a tow bar, we often grounded on slopes. Now we can raise the rear about 8" which is more than enough. Once clear, we drop it back down and leave about 2bar in the bellows.

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[Aerialmark]

Im having it fitted by Rhino installs on Wednesday (VB rear air with pump and gauges ) I don't particularly have a sagging back end but i am aware that there is a lot of weight over the rear axle with the water tanks and also our 2 electric bikes which weigh in at at about 21Kg each without battery. I hope it just helps with all round stability and to combat the wallowing I feel sometimes when being passed by something a little bigger than me or a white van in hyperdrive !

 

[Speve]

Im having it fitted by Rhino installs on Wednesday (VB rear air with pump and gauges ) I don't particularly have a sagging back end but i am aware that there is a lot of weight over the rear axle with the water tanks and also our 2 electric bikes which weigh in at at about 21Kg each without battery. I hope it just helps with all round stability and to combat the wallowing I feel sometimes when being passed by something a little bigger than me or a white van in hyperdrive !

You won’t regret having it fitted

 

[Lucky]

Just fitted air assist at rear of our Trend. With a tow bar, we often grounded on slopes. Now we can raise the rear about 8" which is more than enough. Once clear, we drop it back down and leave about 2bar in the bellows.

Which brand of air assist did you opt for?

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[huck999]

Hi lucky - it was one of these - <Broken link removed>.
Easy fit.