It helps if takes part in a towing course where one learns how to react correctly in a deliberately induced snake. It takes a lot of the scare away when one is suddenly confronted by a similar situation on the open road.
Hi Brian, Sorry to read of your harrowing experience towing your van.
It sounds like lack of noseweight, luckly you haved a car that can absorb a heavier nosewight than than the standard car ie 75kg.
I have always ensured my caravan noseweight is 75kg to match my car, The heavier the nosewight the more stable you will discover you can tow, I came back on the M20 last Monday cruising between 55/60 mph no sign of any wobbles even going down some of the hills.
When driving my estate solo my rear tyres psi is 32, when towing my rear tyres psi is 38, this helps, are the sorento tyre pressures the same solo and towing.
The latest range of vans from Bailey have a nose weight of 90kg plus that is without anything in the front locker, the only way people with a standard car noseweight of 75kg can tow is put heavy objects behind the caravan wheels , this in itself can cause the the caravan to snake, expecally when heavy goods lorries pass .
You say you have a KIA Sorento their is a article in this months Caravan Club Mag,where KIA Motors have stated that when one tyre is worn you have to replace all four tyres at the same time,
Do not use a size and type and wheel that is different from the original one that is originally installed on your vehicle.
It can affect the safety and performance of your vehicle which could lead to handling failure or rollover and serious injury.
Apparently this is all in its manual.
Wishing you lots more caravanning in the future, its a great life.
Royston
It sounds like lack of noseweight, luckly you haved a car that can absorb a heavier nosewight than than the standard car ie 75kg.
I have always ensured my caravan noseweight is 75kg to match my car, The heavier the nosewight the more stable you will discover you can tow, I came back on the M20 last Monday cruising between 55/60 mph no sign of any wobbles even going down some of the hills.
When driving my estate solo my rear tyres psi is 32, when towing my rear tyres psi is 38, this helps, are the sorento tyre pressures the same solo and towing.
The latest range of vans from Bailey have a nose weight of 90kg plus that is without anything in the front locker, the only way people with a standard car noseweight of 75kg can tow is put heavy objects behind the caravan wheels , this in itself can cause the the caravan to snake, expecally when heavy goods lorries pass .
You say you have a KIA Sorento their is a article in this months Caravan Club Mag,where KIA Motors have stated that when one tyre is worn you have to replace all four tyres at the same time,
Do not use a size and type and wheel that is different from the original one that is originally installed on your vehicle.
It can affect the safety and performance of your vehicle which could lead to handling failure or rollover and serious injury.
Apparently this is all in its manual.
Wishing you lots more caravanning in the future, its a great life.
Royston
I never did a towing course because I thought they were mainly about manouvering, reversing etc. Most likely do one now before towing again. The person I bought the van from had done one and gave me the booklet which I read back to front.
Brian thank goodness no one was hurt.
we travelled along the m5 to & from cronwall last week and must say the gusts of wind where very strong at times.
i got caught in the ruts in lane 1 a couple of times which pushed me about a little.
i,ve only been towing 2 years and snaking is one of the most things i worry about when towing.
i think i will book on one of the towing course's.
again glad no one hurt.
ann
we travelled along the m5 to & from cronwall last week and must say the gusts of wind where very strong at times.
i got caught in the ruts in lane 1 a couple of times which pushed me about a little.
i,ve only been towing 2 years and snaking is one of the most things i worry about when towing.
i think i will book on one of the towing course's.
again glad no one hurt.
ann
I am more than a little intrigued by the recent spate of postings by sarah and her 6 dachshunds- Spouting all sorts of figures and some of them make sense but others make me wonder.
In the 20 Jul 2010 00:07 AM thread she posts:-
"did you check nose weight this time one is amazed at how much it can change,i always check mine each time,one time i did not and it felt like a squirrel on the hitch pulled in and checked it, i was slightly light.always check,idealy try to get a noseweight of 7% of vans loaded weight,"
So apart from caryring the nose load gauge around with her, she also carries a full weighbridge, otherwise how do you know the loaded weight?
"as for what happened were your tanks empty,water weighs a lot.were you going downhill? if yes then the van may have tried to push the car on,and banged into the back of you,if this happened then lifting of the pedals would not help,as one needs to increase speed to open up the dampener,and then slow down slowly just slightly tapping brake peddle and alternating with power on,if van starts to push car keep repeating until slowed right down.yes it does work,"
If a trailer is pushing a car it will only do so until the damper has been compressed enough to cause the trailer brakes to start applying. At which point the trailer will its self start to slow down and re-extend the damper until the braking power matches the down hill speed of the whole outfit. There is no logical or practical need to extend the damper. That actually removes the braking force of the trailer brakes and will increase the energy of any instability making it worse.
"if awning was at rear or the chairs this would not have helped,one needs to keep weight over the axle and not more than 1 meter behind axle,otherwise the tail end of the van is heavy and more likely to swing out."
The principal of what she says is basically right, but why 1mtr? The practical distance will vary between caravan designs and on what other items have already been loaded that contribute to the generation and trimming of the nose load. It is perfectly true that additional mass at the extreme ends of a trailer will increase the moment of inertia, but if a few Kg are enough to upset the towability of an outfit then the outfit would already be on the verge of instability without the additional mass. Its not as black and white as Sarah make out.
In the 20 Jul 2010 00:07 AM thread she posts:-
"did you check nose weight this time one is amazed at how much it can change,i always check mine each time,one time i did not and it felt like a squirrel on the hitch pulled in and checked it, i was slightly light.always check,idealy try to get a noseweight of 7% of vans loaded weight,"
So apart from caryring the nose load gauge around with her, she also carries a full weighbridge, otherwise how do you know the loaded weight?
"as for what happened were your tanks empty,water weighs a lot.were you going downhill? if yes then the van may have tried to push the car on,and banged into the back of you,if this happened then lifting of the pedals would not help,as one needs to increase speed to open up the dampener,and then slow down slowly just slightly tapping brake peddle and alternating with power on,if van starts to push car keep repeating until slowed right down.yes it does work,"
If a trailer is pushing a car it will only do so until the damper has been compressed enough to cause the trailer brakes to start applying. At which point the trailer will its self start to slow down and re-extend the damper until the braking power matches the down hill speed of the whole outfit. There is no logical or practical need to extend the damper. That actually removes the braking force of the trailer brakes and will increase the energy of any instability making it worse.
"if awning was at rear or the chairs this would not have helped,one needs to keep weight over the axle and not more than 1 meter behind axle,otherwise the tail end of the van is heavy and more likely to swing out."
The principal of what she says is basically right, but why 1mtr? The practical distance will vary between caravan designs and on what other items have already been loaded that contribute to the generation and trimming of the nose load. It is perfectly true that additional mass at the extreme ends of a trailer will increase the moment of inertia, but if a few Kg are enough to upset the towability of an outfit then the outfit would already be on the verge of instability without the additional mass. Its not as black and white as Sarah make out.
its amazing what you can pick up from wikipedia and snopes, but i notice she has not been back on.
...to understand a caravan snake you first have to understand the term 'oversteer' as applied to a vehicles handling characteristics.
Oversteer is an effect on the rear axle of a vehicle due to a loss of grip with the road surface, resulting in the vehicle turning into a corner at a faster rate than was intended.
Caravans (balanced trailers) are unstable vehicles with forces at the hitch capable of being applied in any direction.
The vertical forces (Pitch) are absorbed by the suspension of the tow car.
The horizontal forces (Yawl) are ultimately absorbed by the grip of the rear tyres to the road surface.
If the yawl force is large enough the rear tyres of the tow car will loose grip with the road and an oversteer situation will result.
This will continue until the angle of attack of the oversteer relative to the forward direction; is sufficient to counteract the yawl force.
The hitch is force back into line and develops a yawl force in the opposite direction due to inertia and a caravan snake develops.
Introducing tension at the caravan hitch during snaking counteracts the yawl forces (Alko ATC) and prevents the snake developing to dangerous levels.
A stabiliser reduces pitching and raises the level at which yawl forces cause a problem.
Other than this it is a case of prevention rather than cure.
Oversteer is an effect on the rear axle of a vehicle due to a loss of grip with the road surface, resulting in the vehicle turning into a corner at a faster rate than was intended.
Caravans (balanced trailers) are unstable vehicles with forces at the hitch capable of being applied in any direction.
The vertical forces (Pitch) are absorbed by the suspension of the tow car.
The horizontal forces (Yawl) are ultimately absorbed by the grip of the rear tyres to the road surface.
If the yawl force is large enough the rear tyres of the tow car will loose grip with the road and an oversteer situation will result.
This will continue until the angle of attack of the oversteer relative to the forward direction; is sufficient to counteract the yawl force.
The hitch is force back into line and develops a yawl force in the opposite direction due to inertia and a caravan snake develops.
Introducing tension at the caravan hitch during snaking counteracts the yawl forces (Alko ATC) and prevents the snake developing to dangerous levels.
A stabiliser reduces pitching and raises the level at which yawl forces cause a problem.
Other than this it is a case of prevention rather than cure.
Stabilisers not only work in pitch but also in yaw. I though the Alco ATC applied the brakes independantly to the trailer wheel and had not effect on the stabiliser itself.
We were in the traffic queue behind your accident.
Felt heart sorry for you when we passed you.
So glad no one was hurt.
Felt heart sorry for you when we passed you.
So glad no one was hurt.
For what it's worth, I have an old trailer home made (not by me) from an old caravan chassis & have suffered bad snaking on 2 occasions with it, once empty & once with a few sheets of plasterboard in it.
Both times it was cased, imho, by excess speed & ruts in the road & both times I was able to bring it back under control by slowing down, I don't know if the lack of brakes on the trailer helped of not.
I would have thought someone would have checked but of the 3 caravans overturned I have seen, they have all been towed by 4x4's, is this just a coincidence ?
Both times it was cased, imho, by excess speed & ruts in the road & both times I was able to bring it back under control by slowing down, I don't know if the lack of brakes on the trailer helped of not.
I would have thought someone would have checked but of the 3 caravans overturned I have seen, they have all been towed by 4x4's, is this just a coincidence ?
Hello Nick,
There have been several attempts on this forum to try and establish any common factors between caravan related incidents, and as yet none have been found that stands up to proper scientific scrutiny.
I am certain that unfair publicity is given to almost any incident that involves a caravan giving the perception that caravans are inherently more prone to having incidents that any other type of vehicle. Consider, we are currently discussing 3 or 4 caravan incidents, which compared to the total number of road incidents must be must be a very small percentage.
No one has the responsibility of collecting data about caravan related incidents and as a consequence whatever we postulate or debate is more often than not hearsay rather than cold hard facts.
I'm not so sure that 4x4's figure more than conventional cars when it comes to overturning, It could just be that as a percentage of the whole caravanning fraternity a higher percentage of people use 4x4's than compared ordinary day to day car usage.
There have been several attempts on this forum to try and establish any common factors between caravan related incidents, and as yet none have been found that stands up to proper scientific scrutiny.
I am certain that unfair publicity is given to almost any incident that involves a caravan giving the perception that caravans are inherently more prone to having incidents that any other type of vehicle. Consider, we are currently discussing 3 or 4 caravan incidents, which compared to the total number of road incidents must be must be a very small percentage.
No one has the responsibility of collecting data about caravan related incidents and as a consequence whatever we postulate or debate is more often than not hearsay rather than cold hard facts.
I'm not so sure that 4x4's figure more than conventional cars when it comes to overturning, It could just be that as a percentage of the whole caravanning fraternity a higher percentage of people use 4x4's than compared ordinary day to day car usage.
being caravanning over 40yrs and my husband has towed over 28 yrs most of the time we see so many caravans not loaded right down at the back etc the nose weight applies more what the car can take we never put items in the over head lockers i keep them in bags and it takes me no longer to put them away than hubby connecting the mains ,gas etc everything is stored on the floor when traveling been up and down the m5 many a time no probs
Brian
Did your Elldis have a version of ATC fitted?
I have wondered what would happen if the ATC malfunctioned and actually induced a snake? I don't know if this can actually hapen, just a wild thought.
Cheers
Dustydog
Did your Elldis have a version of ATC fitted?
I have wondered what would happen if the ATC malfunctioned and actually induced a snake? I don't know if this can actually hapen, just a wild thought.
Cheers
Dustydog
Hi Dustydog,
No atc fitted just a winterhoff hitch stabiliser. I am working in Southam later this week and noticed that Alko have a unit on the Industrial estate there. I will call in and make some enquiries about the ATC system they make. It sounds like a good Idea to me but I imagine its expensive.
Hi to Mel who saw my Van overturned, it was a sorry sight. Did you find conditions for towing your Van okay?
No atc fitted just a winterhoff hitch stabiliser. I am working in Southam later this week and noticed that Alko have a unit on the Industrial estate there. I will call in and make some enquiries about the ATC system they make. It sounds like a good Idea to me but I imagine its expensive.
Hi to Mel who saw my Van overturned, it was a sorry sight. Did you find conditions for towing your Van okay?
Hi all, delighted that Brian's escaped with no personal injury.
My first caravan, purchased new in 1986 was a Perle Olympus with an MTPLM of about 950Kg, which I towed with a 240 Volvo Estate, whose kerbweight was about 1400Kg - I can't remember its allowable towball tolerance, but even at 75Kg would have been more than enough for such a light van. This combo was a 67% towing ratio of car:caravan, so well within the guidelines especially for a newcomer.
Descending a long steep hill on the A350 at about 45-50mph, with no other traffic around and only a light breeze, the van suddenly went into a snake within about 30 seconds of me first noticing it. Fortunately the road levelled at this point and then slightly inclined which enabled me to take my feet off all the pedals and hold the steering wheel with ever whitening knuckles!!, and fortunately the snake then subsided.
The reason?
As a novice, I'd forgotten to check the car's rear tyre pressures, and upon checking the handbook realized that I should've added an extra 5 psi when towing. As the tyres on the 240's had high side walls, as they were prone to flex too much at solo pressures with the van on the back. So I added the extra psi,(I had a tyre pump with me) and continued my journey safely with a valuable lesson learnt.
Although not too familiar with the Sorento, like most 4x4's I believe it has fairly chunky high profile tyres, and I wonder if the rear tyres especially were at the correct pressure?
Mike
My first caravan, purchased new in 1986 was a Perle Olympus with an MTPLM of about 950Kg, which I towed with a 240 Volvo Estate, whose kerbweight was about 1400Kg - I can't remember its allowable towball tolerance, but even at 75Kg would have been more than enough for such a light van. This combo was a 67% towing ratio of car:caravan, so well within the guidelines especially for a newcomer.
Descending a long steep hill on the A350 at about 45-50mph, with no other traffic around and only a light breeze, the van suddenly went into a snake within about 30 seconds of me first noticing it. Fortunately the road levelled at this point and then slightly inclined which enabled me to take my feet off all the pedals and hold the steering wheel with ever whitening knuckles!!, and fortunately the snake then subsided.
The reason?
As a novice, I'd forgotten to check the car's rear tyre pressures, and upon checking the handbook realized that I should've added an extra 5 psi when towing. As the tyres on the 240's had high side walls, as they were prone to flex too much at solo pressures with the van on the back. So I added the extra psi,(I had a tyre pump with me) and continued my journey safely with a valuable lesson learnt.
Although not too familiar with the Sorento, like most 4x4's I believe it has fairly chunky high profile tyres, and I wonder if the rear tyres especially were at the correct pressure?
Mike
The old Sorento does not have a different tyre pressure for towing or any other condition, they remain at 35psi.
The new model however requires an increase from 33psi all round at normal load to 38f --42r towing or maximum load.
Steve W
The new model however requires an increase from 33psi all round at normal load to 38f --42r towing or maximum load.
Steve W
The uksorento forum has done tyre pressures to death over the years.
The overall concensus is that 35psi is the absolute max in any situation. A lot , solo , prefer running at a lower psi of 32.
Personally I have tried variations. Anything above 35psi and the ride becomes very bouncy, rough.
Thus as I tow a lot I leave the tyres at 35psi cold and have had no problems.
Cheers
Dustydog
The overall concensus is that 35psi is the absolute max in any situation. A lot , solo , prefer running at a lower psi of 32.
Personally I have tried variations. Anything above 35psi and the ride becomes very bouncy, rough.
Thus as I tow a lot I leave the tyres at 35psi cold and have had no problems.
Cheers
Dustydog
Hi to all,
As the original poster of this thread just like to let you all know I'm back!
Bought another Caravan last week so I'm giving it another go. Hope to take it out for a test run in the week just to see how it tows and see how the confidence feels. My wife is more nervous than me. Thinking of getting the Alko ATC fitted on it ?. Anyone have any knowledge or opinions on it before I part with my money ?
Regards to all
Brian
As the original poster of this thread just like to let you all know I'm back!
Bought another Caravan last week so I'm giving it another go. Hope to take it out for a test run in the week just to see how it tows and see how the confidence feels. My wife is more nervous than me. Thinking of getting the Alko ATC fitted on it ?. Anyone have any knowledge or opinions on it before I part with my money ?
Regards to all
Brian
An electronic stabiliser, whether it be the AlKo ATC, BPW's iDC, or the LEAS system will always provide total protection against the worst effects of a snake as they are all active systems rather than conventional passive damping systems. They will deploy as soon as they sense any form of instability and prevent the condition from being uncontrollable.
Parksy - Moderator said:
I drive a HGV on the M5 and is probably one of the worst roads for the tracks from HGV, just south of Michal wood sevices south bound at the top of the steep hill there is a very bad spot, it throws the 44 ton lorry towards the hard shoulder they are that bad.
Glad you are all ok, it must have been very frighteing for you, and with a great tow car as well.
Kevin
Hi Brian,
I'ce got the Alko ATC system on mine and it's great reassurance. Thankfully I've not been in a situation where it's been required to operate but knowing it's there is very comforting. Don't think I'd consider buying a van without it now.
I'ce got the Alko ATC system on mine and it's great reassurance. Thankfully I've not been in a situation where it's been required to operate but knowing it's there is very comforting. Don't think I'd consider buying a van without it now.
I am all for systems that help to make cars and caravans safer to tow, but with systems like Anti Lock Brakes (ALB) and the caravan systems like ATC or LEASE, we jump in the car and drive, and often we don't know if the systems are actually capable of doing what they are supposed to do as they only activate when the adverse situation arises.
None of these systems should be used to cover for poor loading and driving, so they are not likely to be caused to operated very often, so unlike the normal brakes, lights and steering, there is virtually no feedback about their operational condition in normal driving.
ALB and ABS usually have dashboard lights, adn I belive that ATC also does, but apart from those visual indications can you say hand on heart that the system is actually fully working?
At least for Anti lock brakes (when it is safe to do so) you can brake hard and feel system through the car, but for anyone who might know the answer, is there anyway a driver can readily check the caravan system system is actually fully working?
None of these systems should be used to cover for poor loading and driving, so they are not likely to be caused to operated very often, so unlike the normal brakes, lights and steering, there is virtually no feedback about their operational condition in normal driving.
ALB and ABS usually have dashboard lights, adn I belive that ATC also does, but apart from those visual indications can you say hand on heart that the system is actually fully working?
At least for Anti lock brakes (when it is safe to do so) you can brake hard and feel system through the car, but for anyone who might know the answer, is there anyway a driver can readily check the caravan system system is actually fully working?
Brian
As I posted some time ago I have the Alko ATC fitted to my caravan I also Have the mercedes Trailer control System
In answer to your question does it work?? and in answer to others who wrote how do you know it has worked???
Note the following:
When travelling through slovania last year I was crossing a Viaduct and the caravan must have been caught by a cross wind unknown to me. All the red lights lit up on my dashboard and the power to the engine cut which aloud me to go onto the hard shoulder of the motorway.
I then swithced off the ignition and then restarted the engine and drove off as if nothing had happened
Would I be without ATC definatly not
Was it worth the money without doubt
How did I arrive at this conclusion (By first hand experiance)
I hope this helps John
As I posted some time ago I have the Alko ATC fitted to my caravan I also Have the mercedes Trailer control System
In answer to your question does it work?? and in answer to others who wrote how do you know it has worked???
Note the following:
When travelling through slovania last year I was crossing a Viaduct and the caravan must have been caught by a cross wind unknown to me. All the red lights lit up on my dashboard and the power to the engine cut which aloud me to go onto the hard shoulder of the motorway.
I then swithced off the ignition and then restarted the engine and drove off as if nothing had happened
Would I be without ATC definatly not
Was it worth the money without doubt
How did I arrive at this conclusion (By first hand experiance)
I hope this helps John
Yes, John, it is perfectly possible to check whether an electronic stabiliser is working or not. In fact, I would recommend trying it, if only to be able to recognise the sensation of a system deploy ahead of an actual need. This could avoid an potential panic reaction later if a situation does occur where the stabiliser may act suddenly and unexpectedly.
The best thing is to select an open area with no traffic and no obstacles. A disused airfield runway would be ideal, but an empty supermarket car park will do if it is large enough. Then, while towing the caravan at about 20 to 25mph, do some see-sawing motions at the steering wheel, as if you were trying to avoid a sudden hazard. If all is working properly, you will feel a tug as the caravan's brakes are applied. If not, just hold the steering rock steady and brake as normal.
The best thing is to select an open area with no traffic and no obstacles. A disused airfield runway would be ideal, but an empty supermarket car park will do if it is large enough. Then, while towing the caravan at about 20 to 25mph, do some see-sawing motions at the steering wheel, as if you were trying to avoid a sudden hazard. If all is working properly, you will feel a tug as the caravan's brakes are applied. If not, just hold the steering rock steady and brake as normal.
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