Options for softening the rear suspension on an ALKO chassis?

[Miggs]

Seems all I have to do is drive over a grain of sand and I get a solid thump like there's little or no suspension travel. Noticed I've even managed to shake my rear reflectors off as their both missing lol! Already dropped tyre pressures from 80 to 60psi, - slight improvement.
Can't run to full air suspension...just too expensive. Sumo springs seem to be just for Ducato chassis.
Any other options? My dentist is making a killing out of me!

 

[1967bowesj]

What rear chassis have you got, alko or van base?

 

[Mr B]

Let the tyres down

 

[Figaro]

If you have Michelin agilis tyres they give a very harsh ride

 

[DJL220]

I have an Alko chassis with Michelin Agilis tyres. I found when I dropped the pressure from 5.5 bar to around 5.0 bar nothing changed. Fast forward to a new set of Michelin and new shocks = transformation! I think the old tyres had flat spots or something due to age and standing around. The shocks where not working either
Would be interested to see what options are out there for a softer ride though

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[Lenny HB]

Can't run to full air suspension...just too expensive.

You can get semi-air for 2k or full air just on the rear for 4k.
Before you do anything with the suspension if you have CP (camping) tyres, get rid of them and fit decent commercial van tyres. The difference in ride quality is amazing.
I changed mine for Toyo Observe Van.

 

[jongood]

You can get semi-air for 2k or full air just on the rear for 4k.
Before you do anything with the suspension if you have CP (camping) tyres, get rid of them and fit decent commercial van tyres. The difference in ride quality is amazing.
I changed mine for Toyo Observe Van.

yes its a shame Op has just fitted another set of Agilis. I don't think semi air would help soften the ride, you would need full air with the mod to the torsion bars.

 

[Hettie's Crew]

Seems all I have to do is drive over a grain of sand and I get a solid thump like there's little or no suspension travel. Noticed I've even managed to shake my rear reflectors off as their both missing lol! Already dropped tyre pressures from 80 to 60psi, - slight improvement.
Can't run to full air suspension...just too expensive. Sumo springs seem to be just for Ducato chassis.
Any other options? My dentist is making a killing out of me!

It depends where your rear suspension is now. We went from the standard Alko with CP tyres to air assistance with C rated, one size larger tyres and the difference was very noticeable, much better.
This uprated the axle from 2000kg to 2240kg but our axle was struggling as standard. When we weighed it, the figure would be 1950-2010 kg so it was overloaded and not providing much further movement.
Fitting the air assistance raised the rear slightly and restored movement, the combination of air and torsion bar working properly gives a very good ride without the crashing or swaying we had previously.
AS at Warrington did the work and made a brilliant job of it after identifying the correct kit. It’s surprising how many variations there are of the Alko swing arms.
If your rear axle isn’t overloaded or on the limit then I don’t think adding air would make any difference.

 

[Lenny HB]

yes its a shame Op has just fitted another set of Agilis. I don't think semi air would help soften the ride, you would need full air with the mod to the torsion bars.

No mention of him fitting new CP tyres.
I found the Toyo tyres made almost as much difference as the full air did.

 

[Lenny HB]

If your rear axle isn’t overloaded or on the limit then I don’t think adding air would make any difference.

Our axles are well under rear 300kg under, full air made a big difference. We are on the Maxi chassis which is a far harder ride than the light.

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[Hettie's Crew]

Our axles are well under rear 300kg under, full air made a big difference. We are on the Maxi chassis which is a far harder ride than the light.

The OP made it very clear he couldn’t run to full air, therefore my post obviously relates to adding air assistance.

 

[jongood]

No mention of him fitting new CP tyres.
I found the Toyo tyres made almost as much difference as the full air did.

Sorry, mixed up op with #5

 

[ivorantony]

On my Alko chassis I have fitted Dunlop air to the rear, it makes a massive difference to the handling in strong winds
with a softer ride as an extra bonus,
I have also fitted Michelins Agilis alpin tyres ( Not the CP type) but with uprated load rating, 121 instead of 115
this has worked well for me after replacing the original Michelins CP tyres that where useless on grip very noisy and harsh ride,

 

[Aspenshaw]

I have Goldschmitt semi air on the rear with Michelin Camping Tyres on both axles.

Michelin say their tyres are designed to work best at 80psi. Ask Michelin and they will tell you to run the rears at 80psi come what may. I do that on the rear. On the front, because the load is less, I run at c60psi having asked Michelin. It can be a bone jarring ride on the poorly maintained roads, on well maintained roads it is smooth.

If you know your axle weights, you may find this useful:

https://www.tyresafe.org/motorhome-tyre-pressure/

Motorhomes are a balance between the safety of the camping tyres by following the manufacturers figures that will give you a harsh ride on poor road surfaces and reducing the tyre pressures or by fitting commercial tyres to get a softer ride. You have to choose.

My experience is Wales has the better road surfaces so take your van over there and see how harsh is the ride. The last time I went to Scotland there were no road surfaces. I assume they have improved them. England is a mixed bag, often reflecting the traffic flow and importance of the road. It may be your problems reflect the road surfaces not your van.

Before I had my rear air bags, I spoke to 4 firms who specialised in motorhome suspension. All 4 advocated full air suspension (too expensive at the time but I wish now I had bitten the bullet) or rear air suspension and softer front front suspension (I didn't bother with the front).

 

[Ninjabob]

It depends where your rear suspension is now. We went from the standard Alko with CP tyres to air assistance with C rated, one size larger tyres and the difference was very noticeable, much better.
This uprated the axle from 2000kg to 2240kg but our axle was struggling as standard. When we weighed it, the figure would be 1950-2010 kg so it was overloaded and not providing much further movement.
Fitting the air assistance raised the rear slightly and restored movement, the combination of air and torsion bar working properly gives a very good ride without the crashing or swaying we had previously.
AS at Warrington did the work and made a brilliant job of it after identifying the correct kit. It’s surprising how many variations there are of the Alko swing arms.
If your rear axle isn’t overloaded or on the limit then I don’t think adding air would make any difference.

We did exactly the same VB Comfort Air and 225 tyres. Give a much less harsh ride and a constant (not higher) ride height and that is with the Agelis tyres at 80psi. I know GlideRite fit a system that will raise the rear higher but wonder how much the torsion bars like that? VB is owned by ALKO and that was good enough to make me pay the extra money over GlideRite.

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[Jev88]

Do you have the tortion beam suspension? BIG tube that fits between both rear wheels and NO sign of coil or leaf springs? If this has not been greased annually with the wheels off the ground then the internal bars can fracture and the result is drooping rear suspension and also a lot harsher ride. Hopefully not your problem as they cost around £3,000 to replace with new and I am referring to older vans.

 

[Hettie's Crew]

We did exactly the same VB Comfort Air and 225 tyres. Give a much less harsh ride and a constant (not higher) ride height and that is with the Agelis tyres at 80psi. I know GlideRite fit a system that will raise the rear higher but wonder how much the torsion bars like that? VB is owned by ALKO and that was good enough to make me pay the extra money over GlideRite.

Don’t know about GlideRite as I never investigated them but our torsion bars were at their limit and providing very little suspension movement, overloaded. The air assist restored the normal working height rather than raised it.

 

[gus-lopez]

My mate's was exactly like that & the axle had never been greased from new. Far better after greasing,

 

[jezport]

Run your tyres at 70 psi cold. They will be around 80psi when hot.

 

[Ninjabob]

Run your tyres at 70 psi cold. They will be around 80psi when hot.

As long as that does not bring on a TPMS warning. You need to run your tyres at the correct pressures as that is what is required for their quoted load index. Your perceived comfort is not a consideration . The torsion bar rear axle needs greasing every year with the ALKO recommended grease with both wheels off the ground - about 10 pumps of the gun.

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[WESTY66]

Crikey!! Is it that bad you have put it up for sale in the classified ads

 

[Ingwe]

Although our Bailey is a lot smaller that the poster’s Bailey, we too have an Alko chassis. We found the ride on the fitted Michelin Agilis Camper tyres at 79 psi all round far too harsh. On advice we lowered the fronts to 65psi and it was a little better. But when our last service indicated that it was time to change tyres, we opted for the Michelin Agilis Cross Climates.
Since then, with the fronts at 65psi and the rears at 79psi, we’ve found the ride smoother, quieter and the road holding, especially in the wet, much improved.

 

[Minxy]

The torsion bar rear axle needs greasing every year with the ALKO recommended grease with both wheels off the ground - about 10 pumps of the gun.

Agreed, we were never informed of this need though and only found out from reading the manual ... yes it was actually read by me AND MY HUBBY!

The below gives info on the grease to use and how to do it.

Greasing / lubricating an AL-KO rear chassis on a motorhome - Motorhome Tour

How to lubricate and grease the axle on an AL-KO chassis. This needs to be done annually or every 20,000km or which ever comes first.

www.motorhometour.co.uk

 

[Lenny HB]

Although our Bailey is a lot smaller that the poster’s Bailey, we too have an Alko chassis. We found the ride on the fitted Michelin Agilis Camper tyres at 79 psi all round far too harsh. On advice we lowered the fronts to 65psi and it was a little better. But when our last service indicated that it was time to change tyres, we opted for the Michelin Agilis Cross Climates.
Since then, with the fronts at 65psi and the rears at 79psi, we’ve found the ride smoother, quieter and the road holding, especially in the wet, much improved.

Run my Toyo's at 56 front 69 rear as recommended by Toyo. Axle loadings are front 1930 kg, rear 2300 kg.

 

[Mitchell]

Run my Toyo's at 56 front 69 rear as recommended by Toyo. Axle loadings are front 1930 kg, rear 2300 kg.

Hi Lenny hope your well , interesting post tell me more about your tyres , and do you know my compactline Alko chassis 69 Reg does it need grease on rear axle for suspension thanks ?

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[Lenny HB]

Hi Lenny hope your well , interesting post tell me more about your tyres , and do you know my compactline Alko chassis 69 Reg does it need grease on rear axle for suspension thanks ?

Yes the axle will need greasing once a year.
I changed to Toyo Observe Van tyres they are a winter tyre with the 3 peaks marking. The ride is so much softer and grip far better in the wet, wear rate slightly higher but 50 quid a tyre cheaper than CP tyres.

We have a CompactLine on order.

 

[Miggs]

Hi all and thanks for the replies. Just wanted to confirm that the new tyres I bought were commercial van tyres and not campers.
Yes, the van is for sale, as with most people, its not until you live with a van for a while that you realise the layout is not ideal for your needs. We want twin fixed beds. I don't think greasing the axle will make much difference but I'll have a look.

 

[Lenny HB]

don't think greasing the axle will make much difference but I'll have a look.

Just saves a few grand if the axle fails due to lack of grease.

If you are getting rid of the van why did you start the thread?

 

[Miggs]

Do you have the tortion beam suspension? BIG tube that fits between both rear wheels and NO sign of coil or leaf springs? If this has not been greased annually with the wheels off the ground then the internal bars can fracture and the result is drooping rear suspension and also a lot harsher ride. Hopefully not your problem as they cost around £3,000 to replace with new and I am referring to older vans.

How would one diagnose an issue with the torsion bar, would that be a workshop job?

 

[Miggs]

Just saves a few grand if the axle fails due to lack of grease.

If you are getting rid of the van why did you start the thread?

After posting, wife suggested rather than throw more money at it, why not swap it now as we had been talking about a different layout.