Hiya. What make of rubber spring assisters do people recommend for my 2015 Ford Focus please. And has anyone got any measurements of the gaps between the springs coils that I could have without me jacking my car up to measure. Thanks.
Spring assisters.
- Thread starter Billy wizz
- Start date
I would try the manufacturers or suppliers web site as that should show you what fits your car.
If you do fit them you do have to tell your insurer as this is a modification, and it might mean an increased premium.
If you do fit them you do have to tell your insurer as this is a modification, and it might mean an increased premium.
The metal spring assisters are better than the rubber inserts as you will still get normal spring rates when lightly loaded and also full spring extension and compression.
There should be no need to fit spring assisters. If you car is riding at less than the manufacturers specification, then you should be looking for the reason.
It will either be worn suspension parts which should be replaced, or the applied load is too large, in which case you need to adjust what you are carrying. Don't forget the car has a maximum nose load value, and some manufactures boot load limits are reduced when towing. Check your manufacturer's specifications.
In addition some vehicles use suspension travel sensors to provide information to the cars stability programmes. The use of non standard suspension parts will corrupt the input data and that might make teh stability programme malfunction.
I’ve used MAD spring assisters on two cars both of which had long rear overhangs but both had suspension height iaw makers specification. The SAAB 9000 CSE had no suspension sensors as it pre dated electronics. The 2014 Skoda Superb estate drove normally when fitted with MAD springs although its rear ride height increased by 12 mm. They were fitted by the Skoda main dealer who had fitted quite a number to Superb estates used fir towing caravans and trailers. Surprised though that a 2015 Ford Focus with short overhang might need them.
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Thanks. I was looking into advice if I did have problems with the ride height under load.
That’s probably the way to take it forwards. Our SAAB pitched front to back when towing but the Skoda had such low clearance under its towball base that it grazed speed bumps in our area which were impossible to avoid by any route. Try your car under load before changing anything.
I go with Prof, having towed with 3 focus models over the years. It would be worth checking the kerbweight and any max tow restriction of the car, and the max noseweight - and then measuring the nose weight of the caravan. This can be done by parking the van level and using a piece of dowel between the hitch and bathroom scales
Propping up a caravan hitch on a stick is not a safe practice.
The correct and safe way to measure noseload is to
Load the car and caravan with all the people and gear they will be taking.
Park the outfit on a horizontal (level) surface
Measure the height th the underside of caravans coupling head.
Arrange to support a set of bathroom scales so the top of the scales as at the same height. This can be achieved by using the caravan step and some magazines.
Uncouple the caravan,
Cover the caravan hitch in a plastic bag to preventange dirt marks
Chock the caravans wheels (to prevent it from rolling (though it shouldn't anyway on a flat surface)
Rest the caravans coupling on the scales
Release the caravan hand brake and raise the jockey wheel and steadies
Read the caravans noseload on the scales.
Measuring the hitch at any other height does not give a true noseload reading. This is particularly important for twin axle caravans.
Grayston Coil Spring Assisters pair
i would not know what the measurements are sorry
i would not know what the measurements are sorry
I’d go with the MAD springs. I use a Milenco noseweight gauge which I check the calibration annually. Doesn’t need to be exact just as long as it’s within a couple of KG either way. After all it isn’t a constant downforce as you trundle along with the airflow over and under the van at different speeds and travelling over dips and rises plus of course weight transfer as you accelerate and brake.
You shouldn't have a problem under load because the maximum allowable rear axle load is the same regardless whether it includes the noseweight or it is arrived at with a fully loaded boot.
Although all the above is correct the reality, in my opinion is much different. Often outfits that should be great on paper provide a mismatch in practice and vice versa.
I once towed with an Isuzu Piazza Sports car.
Some laughed, and it did look daft, but it was an amazing and safe outfit. Plenty of mass, plenty of power and a small rear overhang.
But my Peugeot 4007 (Mitsubishi Outlander), was so soft at the back despite being well within the loading specification meant that MAD spring assisters were essential and made a big difference.
My current Volvo V70 needs nothing doing to it and is just nicely balanced.
But as ProfJohn says, the basic car needs to be up to spec first.
John
Hello Jcloughie
My posting was not about paper matching of towing ratio's.
In my time I have driven countless different combinations of tow vehicles, and trailers, and whilst I do agree some of the outfits on paper should have been fine were sometimes more troublesome than those that might have been not so good. Also I have had some combinations that were well over 100% ratio that towed brilliantly and some that were under 85% which were definitely more skittish, this is on reason why I'm not a fan of the industries towing ratio guidance figures, and what people assume they mean.
Back to this thread - It is a simple fact that provided the combination of the weight carried in the boot in conjunction with a noseload is within permissible limits, the ride height will also be within the manufacturers specifications. If it isn't, then something is wrong, and rather than mask the symptom by fitting spring assisters, the cars load and or suspension should be checked for condition or overload.
My posting was not about paper matching of towing ratio's.
In my time I have driven countless different combinations of tow vehicles, and trailers, and whilst I do agree some of the outfits on paper should have been fine were sometimes more troublesome than those that might have been not so good. Also I have had some combinations that were well over 100% ratio that towed brilliantly and some that were under 85% which were definitely more skittish, this is on reason why I'm not a fan of the industries towing ratio guidance figures, and what people assume they mean.
Back to this thread - It is a simple fact that provided the combination of the weight carried in the boot in conjunction with a noseload is within permissible limits, the ride height will also be within the manufacturers specifications. If it isn't, then something is wrong, and rather than mask the symptom by fitting spring assisters, the cars load and or suspension should be checked for condition or overload.
I would totally support that. We had them on our Octavia some years back and they made a massive difference to stability, towing and solo, and they are a doddle to fit (well, the second one was anyway!!)
Unfortunately in the real world the variation of the noseweight while you’re travelling can vary enormously and at times will exert a downforce on the towbar far in excess of the static loading at these times. This is when you’ll get the benefit of either the assisters or the modified springs that will help by momentarily stiffening up the spring to prevent excessive diving/pitching. It’s not something I think the manufacturers readily factor into everyday cars as the percentage used for towing a heavy trailer is so small. Hence the market for assisters and modified springs. The advantage of the MAD springs is that being a dual rate spring they are unnoticeable when unladen.
I used MAD auxilliary springs on an Astra saloon which had a long boot overhang - but that was after Vauxhall replaced the springs & dampers with a German Opel specification because I complained so much about the pitching when towing - with both modifications it was fine, solo and towing.
You clearly understand the dynamics of noseload, and as you point out it can greatly exceed the static value when in motion. I think you will find the car manufactures are also very aware of the difference between static and dynamic loads, and their specifications take those differences into account, and the springs they fit will be adequate for the job set out in their specifications.
If the vehicle is in good condition and despite all the static loads being within specification, the suspension does bottom out when being driven, the problem is the accelerations produced by the motion are too great. The solution is to slow down when negotiating the obstacles that cause bottoming.
Newton's second law where Force = Mass x Acceleration works perfectly here. If you increase either or both mass or acceleration the force increases proportionately.
Even if you add spring assisters, to prevent the bottoming, the dynamic loads applied to the structure of the vehicles remain the same, its just spread over a longer time.
There is a real danger that fitting spring assistance may tempt drivers who don't appreciate the engineering principles to add load becasue its not bottoming out, or to continue to drive faster when encountering bottoming conditions. Both of these things increases the adverse loading on vehicles. Self levelling suspensions are a classic example where there is less or zero feedback to the driver about the size of the loads applied to the car.
There used to be some car manufacturers who did offer up-rated rear springs for towing, and where they did do that you can be sure they had tested the vehicles and decided that was the correct and solution. It often compromised solo comfort. Where there is no manufacturer approved up-rated spring option, such a modification falls outside of the vehicles type approval, and it the owner must report it to their insurers as a modification.
I did agree with you regarding the above and I thought I made that clear. However. Once it is established that the tow vehicle is in good condition, the towing characteristics can still be poor, even dangerous. This could be fo many reasons but this topic is about loading.
In my experience, uprated springs, or the use of assisters can be a great benefit.
The Peugeot 4007 I referred to earlier is a 4x4 which can take large loads with a tow ball all limit of 100kg. It was in very good condition and the deflection upon loading was small and within limits. (So ‘on paper’) it should have been a great tow car. Nevertheless it did not tow well. And the fitting of MAD assisters made a fantastic difference.
They certainly were not masking any defect within the tow car.
John
My Skoda Superb estate could have been fitted with Skoda Rough Road Package which are available to countries with poor roads such as India, Romania Russia etc or to owners who had to drive on gravel tracks. It consisted of stronger springs which gave a 15mm raised height to the rear and underbody protection panels. Not dissimilar to the Skoda Scout models. It was a dealer or owner fit and from memory cost about £200. But it wasn't available to order via the UK dealer network with RoI being the nearest supply base. So as all I required was a slight increase in loaded height I opted for MAD supplementary springs which gave 12 mm height increase with their preload. My main dealer was happy to fit.
I 100% agree with Tuningdrew. It’s not about the suspension bottoming out or some driving beyond the outfits limits. The pitching can occur well before this and is not sufficiently controlled or dampened by the ow car.
Should assisters be fitted it is a good idea to let the insurance company know. But sometimes they need some convincing that it is for safety reasons.
It must also be considered that some tow vehicles can cope and are within limits. The problem may lie with the tyres. I once had it in writing from Michelin that they are aware that their supple walled premium tyres can induce pitching when towing. One car I had was massively improved by fitting non premium tyres. However I have used Michelin since, and do so now.
John
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