Single shocks vs Dual shocks

Bobdown · Guru

Single shocks vs Dual shocks

Baz421 · Guru

If shocks matched to suspension travel and rate,,, don't need second set, waste of money IMHO

Peter_n_Margaret · Guru

Coil spring suspensions (as well as torsion bars and parabolic leaves) are very hard on dampers because there is zero friction in the suspension system like there is with conventional leaves.
Add to that the very short suspension travel and therefore the very short stroke available for the dampers in question and you have a recipe for them having a very hard and short life. Overheating indicates that.
But as Baz421 says, there is no value simply adding more of the same IF the existing ones are valved appropriately for the vehicle. It is possible however that the existing dampers are not capable of doing the job that they need to do - I doubt that typical caravan manufacturers are capable of a full suspension design and specification and the short stroke nature of those fitted may mean that they are overloaded.

So, in a roundabout way, adding extra dampers to this rig may be a benefit and may not be. Maybe if you have twins they should be different specs. than the ones fitted.
Twin dampers (appropriately specced) do have two distinct advantages:
1. There is more ability to shed heat which would generally make them last much longer.
2. In the event of a failure of a damper, there is still one remaining to help control the suspension. It is worth noting that coils ABSOLUTELY MUST have effective dampers fitted to maintain control of the suspension. Leaves can survive (poorly) without, but coils can not.

To check that the dampers are working effectively, check their temperature after a run on a rough road. They should be at least warm. Any that are not warm are not working.
Cheers,
Peter

Hetho · Senior Member

An excellent reply from Peter.

Regards.

hetho.

Aus-Kiwi · Guru

Chances are they are generic Holden shocks .Fitting two each side will only assist better. They wont have to work as hard . I have two Bilstein shocks each side of My Winebago Explorer . Best thing Ive done . It actually rides smoother . Again coil spring and as std air bag inside coil too . Its not exactly double the restriction . But it keeps the speed of bounce and bump more consistent with out fade !! Like two people lifting .Sharing the load .

steve555 · Member

Was just talking about this with a friend. He seemed to think there was some value in a second set but I'm not convinced. We managed for a heck of a long time with singles - I reckon this is just marketing and an opportunity to charge extra!

1 set of quality shocks, matched to the spring rate is the way to go for me.

-- Edited by steve555 on Friday 1st of March 2019 12:09:25 AM

Aus-Kiwi · Guru

Exactly . Custom shocks would cost more than twins . Plus wear of bushs . Being swing arm it spreads evenly over axis .

Knight · Senior Member

I used to have a single axle Jaco caravan with leaf springs and no shock absorbers, I purchased a kit containing two shock absorbers for each side, mounted opposite with one attached forward of axle and the other rearward of axle.

The difference in ride and handling was significantly better.

Aus-Kiwi · Guru

To think in most cases . On trailers with leaf springs are NOT fitted with shocks !!! Leaf springs dont rebound like coil springs .

KJB · Guru

Any spring without a damper (shock absorber ) gives you the same effect as a "pogo" stick.

BAZZA44 · Senior Member

Motor vehicle manufacturers spend millions of dollars on engineering for a car and yet they only put one shocky per wheel.

Caravan manufacturers think two shocky's per wheel looks tough, so will sell easier than a van with only one shock per wheel.

Hmmmm !!! Think about it.

Barry

Cupie · Guru

Aus-Kiwi wrote:
To think in most cases . On trailers with leaf springs are NOT fitted with shocks !!! Leaf springs dont rebound like coil springs .

My Jayco 2.4t Westport has leaf springs without shockies.

After 20 years & >200,000 km, all bitumen, a recent visit to a suspension specialist revealed that most shackles & pins were still OK. Only 6 of 14 replaced. The leaves are nice & rusty improving friction & they have their original profile (no sag).

The mechanic's comment was 'Its not how far you drive, but HOW you drive' that is important & I suppose how heavily laden.

It rides beautifully & the Jug & toaster sit permanently on antislip mat over the bench top.

Of course, coil springs are a different kettle of fish. If I did dirt roads I would be looking at dual shockies I suppose.

Peter_n_Margaret · Guru

BAZZA44 wrote:
Motor vehicle manufacturers spend millions of dollars on engineering for a car and yet they only put one shocky per wheel.

OKAs were built with 2 dampers to each wheel.

In any case, most vehicles have much better suspension than most caravans.

Cheers,

Peter

-- Edited by Peter_n_Margaret on Sunday 3rd of March 2019 11:12:05 PM