Never towed a van and got scarred by snaking!

[JTQ]

One should differentiate between a nervous or twitchy outfit and a snake. I have seen twitchy outfits where the back end of the caravan is moving side to side maybe a foot or so for many miles on end with the driver obviously oblivious to what was going on behind him

Quite correct in that some movement is inevitable and is significantly a different issue to a snake; the nature of the snake is that the yawing energy builds up whereas the benign movement decays away.

This natural movement as opposed to the snake is where the role of the so called "stabilisers" comes into play, they are all but useless in countering a snake where the energy involved quickly overwhelms any damping they offer.

The "stabiliser" [not a label Ilike for a modest damper, as Joe Bloggs naturally and quite reasonably assumes it does what its name implies] serves a very useful purpose in taming the normal trailer movements, reducing the magnitude and making for a less human fatiguing towing experience.

A downside is it hides the first hints of a potential snake, though that's character will quickly become apparent, as a puny bit of ball friction is no master of a snake.

 

[Lutz]

Quite correct in that some movement is inevitable and is significantly a different issue to a snake; the nature of the snake is that the yawing energy builds up whereas the benign movement decays away.

This natural movement as opposed to the snake is where the role of the so called "stabilisers" comes into play, they are all but useless in countering a snake where the energy involved quickly overwhelms any damping they offer.

The "stabiliser" [not a label Ilike for a modest damper, as Joe Bloggs naturally and quite reasonably assumes it does what its name implies] serves a very useful purpose in taming the normal trailer movements, reducing the magnitude and making for a less human fatiguing towing experience.

A downside is it hides the first hints of a potential snake, though that's character will quickly become apparent, as a puny bit of ball friction is no master of a snake.

Here again one needs to differentiate between passive stabiliser systems such as friction dampers in the hitch and active electronic systems such as ATC which don't deploy until they sense excessive side-to-side movement.
All passive systems do is to raise the threshold speed at which snaking can occur. Once this exceeded, they serve little to no further useful purpose. The forces involved are then simply too great for the stabiliser to cope.
On the other hand, active systems, while not preventing the onset of instability, will intervene when the situation becomes critical. That's why a combination of an active and a passive system is about the optimum that you can get.

 

[JTQ]

Here again one needs to differentiate between passive stabiliser systems such as friction dampers in the hitch and active electronic systems such as ATC which don't deploy until they sense excessive side-to-side movement.

Here, in the UK there is I suspect a natural differentiation between active and passive systems, we use quite different "labels", one is readily described even in sale literature as a "Stabiliser", the other typically as an "ATC" or in cases directly as "active trailer control".

Then there are different active systems ones that attempt to dynamically counter the trailers antics, and the far simpler breed that just bang on some trailer braking to enable the tow vehicle to pull the trailer into line.
I much prefer the latter's basic direct simplicity, not involving way more time constants for its effect to work its way through to sucess, plus a cheapness and lack of complexity.

 

[ProfJohnL]

Lutz correctly mentions the "threshold" point at which an uncontrolled sway begins, and he also suggests its typically between 50 an 60mph, And whilst that may be typical, it can easily be much lower if the outfit has not been set up correctly, or you encounter deteriorating road conditions, such a major change in the quality of the road surface like rutting, or a bow wave from a passing vehicle, and its these issues which are more likely to catch out the novice or careless caravanner.

 

[Lutz]

Here, in the UK there is I suspect a natural differentiation between active and passive systems, we use quite different "labels", one is readily described even in sale literature as a "Stabiliser", the other typically as an "ATC" or in cases directly as "active trailer control".

Then there are different active systems ones that attempt to dynamically counter the trailers antics, and the far simpler breed that just bang on some trailer braking to enable the tow vehicle to pull the trailer into line.
I much prefer the latter's basic direct simplicity, not involving way more time constants for its effect to work its way through to sucess, plus a cheapness and lack of complexity.

I intentionally referred to active stabiliser systems rather than ATC because I believe ATC is a registered trade mark of AlKo which would mean that, in the strict sense, it can only be used to describe their system.

I'm not sure what dynamic systems you are referring to other than those that, quote, "just bang on some trailer braking". I'm not sure of any other systems on the market. Maybe they have been developed, but I've never seen any on sale. Basically, they can't be made to work with a existing simple mechanical rod or cable actuators so they would be, by their very nature, excessively complex and sophisticated.

 

[Raywood]

Lutz correctly mentions the "threshold" point at which an uncontrolled sway begins, and he also suggests its typically between 50 an 60mph, And whilst that may be typical, it can easily be much lower if the outfit has not been set up correctly, or you encounter deteriorating road conditions, such a major change in the quality of the road surface like rutting, or a bow wave from a passing vehicle, and its these issues which are more likely to catch out the novice or careless caravanner.

I do think a caravan would have to be very badly set up to snake at under 50 mph. From what I have seen it is generally nearer 60, and usually more.

 

[Buckman]

If a car not towing is badly loaded surely that can also lead to the car snaking i.e. the load in the rear is causing the front end to raise significantly. see that on more than one occasion with pickups where the bin is well overloaded. All they need to a bump in the road for the wheels to lift right off the road.

 

[Dustydog]

The threshold speed mentioned is imo quite a variable. The well seasoned caravanner will know exactly where this point is . In my case I am confident it is well above the legal limit.
For the benefit of the OP I think he must consider accurately his
Noseweight, end loading, top heavy loading, tyre pressures (all of them), tyre types, suspension type and condition, nose up or nose down (controversial), speed, stabiliser condition, length of rear overhang. Speed limits road surface weather wind.
I rarely notice caravans snaking these days. Have you noticed how much longer they are now?
Speed wise 58 mph suits my outfit and the engine rpm is pretty well at the listed max torque output. Great for fuel consumption.

 

[Lutz]

I do think a caravan would have to be very badly set up to snake at under 50 mph. From what I have seen it is generally nearer 60, and usually more.

Actually, it is seldom over 60mph, but that doesn't mean to say that an outfit can't be perfectly docile at 70 or even 80mph so long as nothing occurs which could disturb the state of equilibrium, such as a sudden bout of crosswind or emergency evasive action. Under perfect conditions there is no limit to the speed at which one can tow, as manifested by the world speed record for towing a caravan which, I believe, stands at 143mph, but woe betide you if anything occurs at that speed which could knock the outfit off its intended course.

 

[Lutz]

If a car not towing is badly loaded surely that can also lead to the car snaking i.e. the load in the rear is causing the front end to raise significantly. see that on more than one occasion with pickups where the bin is well overloaded. All they need to a bump in the road for the wheels to lift right off the road.

For that sort of thing to happen one would have to exceed the permissible rear axle load of the pickup quite considerably.

 

[JTQ]

I'm not sure what dynamic systems you are referring to other than those that, quote, "just bang on some trailer braking". I'm not sure of any other systems on the market.

I refer to dynamic systems that enhance the tow vehicle's electronic stability features to recognise the vehicle is towing and address the extra needs to counter that, as an example my Land Rover's "Trailer Stability Assist"; a similar system being offered by other makers.
Here; in LR's case there is no direct control or input of any caravan feature, ie brakes, wheel speed sensors or accelerometers, the task is addressed solely by the LR's own tools including differential braking, throttle commands and motion sensing.
IMO, a very indirect technique where a bundle of extra time constants come into play, rather than a system as ATC [there are as you know directly others] where the sensing and corrective action other than the "pull", are on the trailer itself; albeit in a somewhat unrefined way but exceedingly focused on just the issue being addressed.

I have never ever sensed the LR doing anything, but quite frequently the van's ATC though always where it has not quite made the right call, just a safe somewhat pre needed intervention. I am happy that it does, reassuring it's there and actually "working" with its mind on the job, if not the brightest in intelligence.

 

[Buckman]

For that sort of thing to happen one would have to exceed the permissible rear axle load of the pickup quite considerably.

Seem that on a number of occasions even in the UK!

 

[Ray scutt]

Hi have a Atc fitted to your van it is fitted to the brakes on the caravan then when it starts to snake itputs the brakes on slightly and levels it out its a good bit of kit and some insurance companies will give you 5% discount

 

[Christhecaravanner84]

I’m a new tower and by no means an expert, but my two pennth….
Mirrors, mirrors, and mirrors. Did I mention mirrors? Any good driver checks mirrors regularly but they take on a new level of importance when towing . I highly recommend a course, even if you don’t need to do one legally. Lane discipline is important. “Drive that trailer” as my instructor kept telling me. The trailer will follow you, but it might not be taking the path it needs to . Check those mirrors, check and check again. Especially check for death wish cyclists in your near side mirror when turning left.

Don’t worry about being nervous on your first trip, just don’t be a gibbering wreck. Take your time. I got horn blasted a couple of times because I was dithering at roundabouts. Just smile and chuckle. No point in trashing your caravan just to please some bonehead in an Audi.

 

[Hutch]

I think you have got it there Chris. I have a route through Aylesbury, and it is where two lanes "Zip" into one. Not many folk understand that the Highway code "ZIP"" merging. And we get cut up every time. .
The nice BMW, Audi Mercs eventually give way. To a SantaFe and a 7 Meter long caravan.

 

[Hutch]

I have towed Caravans With and without ATC help and also Alko stabaliser, the one on the tow hitch. On a motorway or Heavy use dual carrigeway, the HGV ruts give a sway, which may make a new to towing think , that is a snake, Oh No it is not, when you get a snake, it is unforgetable. And you py attention as to how it happened, 40 mph going down hill is memorable.

 

[Christhecaravanner84]

I have towed Caravans With and without ATC help and also Alko stabaliser, the one on the tow hitch. On a motorway or Heavy use dual carrigeway, the HGV ruts give a sway, which may make a new to towing think , that is a snake, Oh No it is not, when you get a snake, it is unforgetable. And you py attention as to how it happened, 40 mph going down hill is memorable.

I thought I had a snake at one point during my first trip on the motorway. It was just not being used to the sensation of other other high sided vehicles passing.

 

[Hutch]

I thought I had a snake at one point during my first trip on the motorway. It was just not being used to the sensation of other other high sided vehicles passing.

Yes Chris, HGV, and especially Car transporters are the worst. Don't get over confident. In Gemany with my 1645 KG van I did get up to aboout 70 ish, mph, totally stable, BUT it must have been a good day, I stick to about 55 /60 mph.

 

[Hutch]

I also had a very bad Snake, more like a huge Anacconda, , passing an HGV, at 60 ish mph, a huge sway, our ATC kicked in and saved our journey, letting off the throttle, would not have saved us.
But that was due to myself badly loading the caravan, too much behind the axle.

 

[RogerL]

I thought I had a snake at one point during my first trip on the motorway. It was just not being used to the sensation of other other high sided vehicles passing.

You highlighted mirrors, use them to watch HGVs and coaches coming past you - before they reach your tail move over towards the edge of your lane nearest them - this encourages them to give you more space - then as they come past move towards to other edge of your lane to give even more space.

Motorway lanes are 12' normally so you've got a couple of feet each side.

 

[Raywood]

You highlighted mirrors, use them to watch HGVs and coaches coming past you - before they reach your tail move over towards the edge of your lane nearest them - this encourages them to give you more space - then as they come past move towards to other edge of your lane to give even more space.

Motorway lanes are 12' normally so you've got a couple of feet each side.

Yes I try to do this as well, although you can get caught out and miss the odd one overtaking.

 

[outdoorguy]

So I did my first ~85 miles trip yesterday, luckily mostly motorway and dual carriages roads, traffic was low to moderate. On the motorway, I 'befriended' a Lithuanian HGV which was going around 48 to 55 miles all the time and was comfortable. The car felt obviously different but never had a worrying wobble. What is nice, is when the foot off the accelerator, starts to slow down instantly - it's reassuring.
Also, reversing was much easier than I thought. The only bad thing was 20 mpg - with a tiny tank of Honda CRV, I will have to spend a lot of time refueling...

 

[Hutch]

Thats good news and obviously your pleased, nice weather, next thing for you will be country lanes or bad weather.
Glad it all went well for you.

 

[Hoomer]

Here we go! '85% limit' - ooooh look at that, you're near the sacred 100% limit, tragedy awaits!

I've been towing with a CRV 2.0 petrol auto for well over a decade - take no notice of this '85% rule', (Neither does anyone across the Channel), and I tow at 1500kg.

Never had a snake, but I've seen plenty, usually a Range Rover or some similar behemoth, towing a a fairly light caravan far too fast.

Just load it sensibly, the CRV is a very good and stable tow car (very short rear overhang) and crack on.
Yes, the automatic CRV's are downrated by Honda to a VERY conservative 1500kg, but the manual ones are allowed to tow at 2,000kg.

The 1500kg rating of the automatic CRV is 100% to protect the gearbox, and nothing to do with the car being at any towing limit.
(Rather perversely, Honda now you the same much stronger ZF box as a Range Rover Evoque and still downrate the car to 1500kg!)

And… if you do sense the caravan getting uppity, DO NOT BRAKE, just lift off the accelerator and the car will sort itself out.

 

[otherclive]

Here we go! '85% limit' - ooooh look at that, you're near the sacred 100% limit, tragedy awaits!

I've been towing with a CRV 2.0 petrol auto for well over a decade - take no notice of this '85% rule', (Neither does anyone across the Channel), and I tow at 1500kg.

Never had a snake, but I've seen plenty, usually a Range Rover or some similar behemoth, towing a a fairly light caravan far too fast.

Just load it sensibly, the CRV is a very good and stable tow car (very short rear overhang) and crack on.
Yes, the automatic CRV's are downrated by Honda to a VERY conservative 1500kg, but the manual ones are allowed to tow at 2,000kg.

The 1500kg rating of the automatic CRV is 100% to protect the gearbox, and nothing to do with the car being at any towing limit.
(Rather perversely, Honda now you the same much stronger ZF box as a Range Rover Evoque and still downrate the car to 1500kg!)

And… if you do sense the caravan getting uppity, DO NOT BRAKE, just lift off the accelerator and the car will sort itself out.

It’s not a “limit” and it’s not a rule”. It’s a guide.

And Hondas 1500 kg limit for the auto is a towing limit, what else do you think it could be? The engine may tow higher loads but if it’s a gearbox limitation howver you look at it it’s a towing limit. How do you know the Honda ZF gearbox is the same as the Evoque. Do the cars have identical torque power curves, gear ratios, engine management software? I very much doubt they are the same apart from having the same number of ratios and a ZF manufacture.