SPRING ASSISTERS

[Happy-Lappy]

I am considering having Progressive Spring Assisters fitted to my Renault Espace, to stop the existing springs from bottoming out when towing and carrying three bikes on the tailgate.

Does anyone know if there is a difference between the ones manufactured by Grayston Engineering and the equivalent ones manufactured by MAD Suspension Systems.

The prices are near enough the same, but I am not sure of the quality and performance/ride handling of these, any comments will be most welcome,

thanks in advance, Martin

 

[WatsonJohnG]

I had the M A D variable rate springs fitted to my XT and they were very good

Sorry I can't answer the question as asked but I can recommend the M A Ds

 

[Amanda_5109471]

I have the Grayston Engineering ones fitted to mine, not a Renault though. The quality and engineering seem fine. They do stiffen up the rear end when solo, but it's not noticeable after a few weeks.

 

[RogerL]

The Grayston type work by jamming a coil or two of each spring giving a stiffer spring at all suspension heights. They aren't specific to vehicles and may not have actually been tested on your vehicle.

MAD are rising rate springs which have little effect when unladen but stiffen the suspension considerably when fully laden. They're specific to vehicles and will have been tested as such.

MAD are a much better engineering solution to this problem than Grayston. I had a set on my Astra which worked very well.

Having said all that Happy-Lappy's problem may simply be overloading! Caravan noseweight, three bikes on the tailgate, full load inside is probably simply too much for a softly sprung car to cope with.

 

[Lutz]

..... in which case the towcar's maximum permissible rear axle load is probably being exceeded anyway.

 

[Ogre]

I agree with Lutz. FAR too much weight on the back end of an Espace.

If you're carrying three bikes (and presumably three people to ride them), plus luggage, van equipment, and holiday extras, you're going to be overloaded.

Putting spring assisters on the vehicle will not alter this basic fact. It's fraught with safety and mechanical relaibility issues, and personally I'd be looking at replacing the Espace with something more suitable for these kind of loads.

 

[ProfJohnL]

It seems that Lutz has stolen my thunder on this one.

It applies to any normal road vehicle that if the springs are bottoming out, you are either overloading the axle, or driving too fast over obstacles.

Spring assisters do not increase the allowable loading limits.

The only other possible explanation is that you may have a damaged spring that has become shorter.

Technically spring assisters are not necessary for the vehicle, provided all loading limits are observed, but in some cases they can make the ride more comfortable.

 

[WatsonJohnG]

I agree with the statements about overloading etc

But people like Grayson,M A D,Koni,Armstrong etc etc would not tool up and manufacture suspension aids/improvements if there was not a sale for them---they would all go bust

In the real world a manufacturer produces a car for a wide market and so towing a caravan may not be his number one priority

Not everyone can afford to just change the car when they find it sags a bit at the rear.

French cars in particular seem to give a softer more comfortable ride solso but that is not so good for towing

Don't wish to get embroiled in more pantomime

OH NO IT ISN'T exchanges but wanted to give more balance to the debate (without using spring assisters)

 

[ProfJohnL]

I agree with the statements about overloading etc

But people like Grayson,M A D,Koni,Armstrong etc etc would not tool up and manufacture suspension aids/improvements if there was not a sale for them---they would all go bust

In the real world a manufacturer produces a car for a wide market and so towing a caravan may not be his number one priority

Not everyone can afford to just change the car when they find it sags a bit at the rear.

French cars in particular seem to give a softer more comfortable ride solso but that is not so good for towing

Don't wish to get embroiled in more pantomime

OH NO IT ISN'T exchanges but wanted to give more balance to the debate (without using spring assisters)

Hello John,

The likes of Grayson, M A D, Koni, Armstrong etc, are of course in business to make money, that is what business is primarily about, but as with many other products, these after sales markets are about pandering to a customer 'whim' rather than a necessity. If up rated dampers were a necessity because of technical failing of the original vehicle design, then the manufactures would be legally liable for selling goods unfit for purpose!

Don't forget that all new cars have to be rated by the manufacture for their towing ability during the type approval process. This set the towing limit for the design.

We do not see vast numbers of people suing dealers/manufactures so I think it is reasonable to assume that the majority of customers are basically satisfied with their vehicle as originally purchased and the manufactures specification is sound.

If someone finds it imperative to change the damper specification so they can tow, then it is likely they are actually asking the vehicle to do more than it was designed to do.

 

[Angus1]

Tend to go along with John G on this one, having used MAD`s on a few cars (particularly Peugeots) in the past.

With regards to John L`s point about if you have to mod it to tow it may not be fit for purpose anyway, I`ve yet to buy a new car that comes with a towbar from the factory as standard, or that has twin electric sockets (or a 13 pin) in its spec.

 

[colin-yorkshire]

hi all

I would agree with watson(johnG)on his observations on french cars especialy renaults.

my megane does not have any rear springs at all but is fitted with torsion bar suspension which is difficult to adjust amd almost impossible to stiffen up.the only way to stop the back end sinking is to reduce the weight on the back of the car (empty the boot when towing)and reduce the nose weight ect, the mover I fitted behind the axel might help (I hope)but I definetly would not change the car just to tow the van 4 times a year, no way.

as has been said a manufacturer designs and makes a car to do a specific job and towing a van may not be the top priority so sticking 75kg of nose weight on to a fully loaded rear end exeeds what the designer had in mind.

after market parts do have a use though to make the ride more comfortable ect,but in my view the only real answer is to reduce the weight on the rear axel.

colin

 

[Happy-Lappy]

Thanks for all the replies.

When I tow with a full load, I always remove the two rear most seats, but these are then replaced with the full awning and fridge. I have checked all my maximum load limits and I can assure you that none are exceeded.

One option is to put the awning over the axles of the van, as long as this does not take me over the MTPLM.

I am aware that having the Spring Assisters fitted will not enable me to exceed my manufactures limits, but they will help to stop the rearend from sinking and keep the van level. When the new Calor bottles come out in March, I could always drop my noseweight to 60kg.

One last option is to have three bikes on the roof and one in the van,

thanks again for the replies and best regards to all, Martin

 

[Lutz]

JohnG will probably give a sigh at my reply but as the car cannot be loaded any more when towing than if it the boot were fully loaded, one can argue that the car manufacturer has done all that is necessary. Whether 75kg is in the boot or pushing down on the towball makes no difference. Of course, self levelling suspension would be of benefit but then that applies to anyone travelling regularly with a lot in the boot, too.

My car came out of the factory with towbar and 13-pin electrics already fitted as a regular production option, Angus.

 

[WatsonJohnG]

JohnG will probably give a sigh at my reply but as the car cannot be loaded any more when towing than if it the boot were fully loaded, one can argue that the car manufacturer has done all that is necessary. Whether 75kg is in the boot or pushing down on the towball makes no difference. Of course, self levelling suspension would be of benefit but then that applies to anyone travelling regularly with a lot in the boot, too.

My car came out of the factory with towbar and 13-pin electrics already fitted as a regular production option, Angus.

No sigh Respect for your point of view as always

 

[Happy-Lappy]

Lutz,

The higher spec model of my Espace does have self-levelling suspension as standard, but as the spring assisters would be a far cheaper option to fit, this is reason why I asked for any recommendations on the two known manufactures.

All your points with regards to overloading have been taken on board and rest assured all maximum limits are adhered to,

best regards, Martin

 

[Angus1]

Hi Lutz,

I`d be interested to know what make of car you have that is fitted with a bar and electrics at the factory.

Before getting my Passat, I checked with various dealers and in the UK VW, Ford, Vauxhall, Saab and Honda of the cars I considered all stated that as far as they were concerned I could order a car with a bar but it would be a dealer fit NOT a factory fit. In which case I would view it as any other bolt-on accessory.

Similarly if I had ordered roof cross bars for my Passat estate does anyone really think it would come down the line like that?

 

[Happy-Lappy]

Getting back to my original problem, my car is designed to carry seven adults, when I tow its just the family of five. The noseweight plus awning is around 115kg, this is less than two average weight adults. Maybe the springs are worn, so will the assisters help? or should I just replace the original springs,

best regards, Martin

 

[Lutz]

All popular models from German car manufacturers are available with towbars and 13-pin electrics as a factory-fitted option. This is because, in Germany, subsequent fitting by a dealer requires the car to be re-tested by the T

 

[Angus1]

Thanks Lutz, I follow that, but obviously there are glaring differences between Germany and the U.K as neither the Passat (definately German) or Mondeo/ Vectra (German?Belgian/) would have been supplied to me in the U.K with a factory fit bar. The same also applied to my last Passat which was a definate factory order (4 month wait) because of the spec I wanted.

 

[Lutz]

Assuming the kerbweight (including the driver) of the Espace is around 1900kg, another 4 passengers of average weight (75kg) would add 300kg, and the noseweight a further 115kg, making a total of 2415kg. Without exceeded the maximum permissible GVW of 2605kg (that's what my data tells me), this would leave 190kg for other payload (including the bikes), which is not particularly generous for this size of vehicle.

 

[Lutz]

Thanks Lutz, I follow that, but obviously there are glaring differences between Germany and the U.K as neither the Passat (definately German) or Mondeo/ Vectra (German?Belgian/) would have been supplied to me in the U.K with a factory fit bar. The same also applied to my last Passat which was a definate factory order (4 month wait) because of the spec I wanted.

If the UK marketing organisation does not wish to offer the same options as on the Continent, then this is their decision and not the car manufacturers'. Technically, there's no reason why they shouldn't make factory-fitted towbars available.

 

[Joseph_5097700]

Assuming the kerbweight (including the driver) of the Espace is around 1900kg, another 4 passengers of average weight (75kg) would add 300kg, and the noseweight a further 115kg, making a total of 2415kg. Without exceeded the maximum permissible GVW of 2605kg (that's what my data tells me), this would leave 190kg for other payload (including the bikes), which is not particularly generous for this size of vehicle.

Grayston are a British company and MAD are Dutch is that sways your decision.

Grayston progressive springs are different to spring assisters. The prog springs are extra springs that are used in tandem with the vehicles own springs.

The spring assisters are like rubber donuts that fit in between the vehicles own spring.