Caravan Stability

[eckiew]

" I have inspected hundreds of accident damaged vehicles professionally and the funny thing is that the faster they had been travlling before impact the more damage was evident after the collision.

The answer to the question 'what action were you taking immediatly before the impact' 'I had my foot hard on the brake' sounds better than 'I had the throttle flat to the floor' "

I do wonder bout some of the posts on this forum!

For alexander the 'Professional'

I don't think anyone has suggested foot to the floor or fantastic speed. The difference between using a little extra speed at the correct time for a brief extricate from trouble momet can be the difference between the number of vehicles you have examined and the potential numbers that you could have examined if drivers had not avoided those rare but difficult driving moments that could have lead to an impact!

Or are you suggesting in your professional opinion that more of us just crash rather than use good natural instinct and driving skill to avoid problems caused by others

I guess the extra work would benefit you and your colleagues

Euro

I don't have to justify my qualifications or experience to you or anybody else on the forums and frankly I don't care how you drive as long as we are not on the same stretch of road!

 

[Guest]

" I have inspected hundreds of accident damaged vehicles professionally and the funny thing is that the faster they had been travlling before impact the more damage was evident after the collision.

The answer to the question 'what action were you taking immediatly before the impact' 'I had my foot hard on the brake' sounds better than 'I had the throttle flat to the floor' "

I do wonder bout some of the posts on this forum!

For alexander the 'Professional'

I don't think anyone has suggested foot to the floor or fantastic speed. The difference between using a little extra speed at the correct time for a brief extricate from trouble momet can be the difference between the number of vehicles you have examined and the potential numbers that you could have examined if drivers had not avoided those rare but difficult driving moments that could have lead to an impact!

Or are you suggesting in your professional opinion that more of us just crash rather than use good natural instinct and driving skill to avoid problems caused by others

I guess the extra work would benefit you and your colleagues

No one has questioned your qualifications alexander or experience.

I dont have to justify mine or my experience and have a exemplary driving record and have always had a clean license.

Plain fact is that whatever your job might be re crashed vehicles you are seeing the ones that crashed not those that avoided crashing. Plain fact!

 

[Gafferbill]

I think I will fit booster rockets to the back of my caravan............ at the first sign of trouble I will fire them up and accelerate out of trouble whether it is a ladder or a snake!!

 

[eckiew]

" I have inspected hundreds of accident damaged vehicles professionally and the funny thing is that the faster they had been travlling before impact the more damage was evident after the collision.

The answer to the question 'what action were you taking immediatly before the impact' 'I had my foot hard on the brake' sounds better than 'I had the throttle flat to the floor' "

I do wonder bout some of the posts on this forum!

For alexander the 'Professional'

I don't think anyone has suggested foot to the floor or fantastic speed. The difference between using a little extra speed at the correct time for a brief extricate from trouble momet can be the difference between the number of vehicles you have examined and the potential numbers that you could have examined if drivers had not avoided those rare but difficult driving moments that could have lead to an impact!

Or are you suggesting in your professional opinion that more of us just crash rather than use good natural instinct and driving skill to avoid problems caused by others

I guess the extra work would benefit you and your colleagues

Euro

It could well be that I observe a lot of 'near misses' but I have better things to do than get into a tit for tat with you but safe driving wherever you go, bye

 

[Gumbo]

Just pack it Right, Go at the correct speed !! Don't exceed say 65 mph. Make sure the car and van is a good combination, and Bobs your Uncle. Oh and check the tyre pressure Car & Van.

Lutz, Scotch Lad, and Euro anything missing ????

 

[Gumbo]

Because you all taught me what I know and I feel Safe. I drove down through Central Scotland today with lots of side winds etc and felt fine. Cheers to all of you.

 

[ProfJohnL]

Just pack it Right, Go at the correct speed !! Don't exceed say 65 mph. Make sure the car and van is a good combination, and Bobs your Uncle. Oh and check the tyre pressure Car & Van.

Lutz, Scotch Lad, and Euro anything missing ????

Assuming you are in the UK why exceed 60mph when towing, anything greater is speeding?

 

[xtrailman]

Assuming you are in the UK why exceed 60mph when towing, anything greater is speeding?

John l

you are showing signs of paranoia?

Surly you must be aware that a speeder indication of 65mph is probably under 60mph true speed?

 

[xtrailman]

John l

you are showing signs of paranoia?

Surly you must be aware that a speeder indication of 65mph is probably under 60mph true speed?

 

[ProfJohnL]

John l

you are showing signs of paranoia?

Surly you must be aware that a speeder indication of 65mph is probably under 60mph true speed?

Who said that?

 

[Lutz]

A previous thread in this forum references a report by the University of Bath. One of the findings in this report was that for every outfit there is a critical speed above which it will not recover from an instability without action of some sort, either on the part of the driver or by an active stabiliser system. This critical speed is usually in the range between 50 and 60mph, depending on the setup. For this reason, 60mph is a sensible maximum.

 

[ProfJohnL]

Rob I am sure you will have followed as much of the advice as is practical from this thread. Several suggestions have been made and hopefully one or more will resolve your problem.

I am sorry that my remark about keeping to the speed limits has drawn such vitriole from others.

 

[xtrailman]

John L

Perhaps if you didn't jump onto every post that may mention driving at illegal speeds, then you would not get so many derisive comments.

I think we are ALL aware of the speed limits. And i am sure that 95% of the time we drive with in the limits, while towing.

Most of my towing is done between 50 to 60 on motorways, however on a down hill stretch, or while overtaking, then for a short time the legal limit may be inadvertently exceeded.

We do not need to be lectured.

Lutz

I believe the caravan stability game on the Bailey site, and the other information on that site, are the results from the bath study.

Interestingly it does make a reference if i recall correctly, to caravan weight, more weight can lead to increased instability. Also the 7% nose weight guide is mentioned.

Rather conflicts with your comments re the 85%/7% being out dated?

Quote from bath study

1/ "Yaw inertia is a measure of how far weight is from the centre of gravity, which in this case is across the caravan axle. Reducing the overall weight of the trailer will reduce Yaw inertia and concentrating that weight near the mid-axle point will greatly reduce Yaw inertia."

2/ "It is also recommended that there is enough weight in front of the axle to achieve a nose weight that is as high as allowed by the vehicle manufacture (7% of the caravan weight) "

http://www.towingstabilitystudies.co.uk/stability_studies.htm

 

[Lutz]

Lutz

I believe the caravan stability game on the Bailey site, and the other information on that site, are the results from the bath study.

Yes, I would think that the stability game employs the same math models that were used by the Bath researchers.

Interestingly it does make a reference if i recall correctly, to caravan weight, more weight can lead to increased instability. Also the 7% nose weight guide is mentioned.

Rather conflicts with your comments re the 85%/7% being out dated?

I presume by "caravan weight" you mean noseweight. I can't find any reference to the 7% guide in the report "The Dynamics of Towed Vehicles" submitted by Christopher Killer of the University of Bath School of Mechanical Engineering so I really don't know where you got your information from.

 

[Lutz]

John L

Perhaps if you didn't jump onto every post that may mention driving at illegal speeds, then you would not get so many derisive comments.

I think we are ALL aware of the speed limits. And i am sure that 95% of the time we drive with in the limits, while towing.

Most of my towing is done between 50 to 60 on motorways, however on a down hill stretch, or while overtaking, then for a short time the legal limit may be inadvertently exceeded.

We do not need to be lectured.

Lutz

I believe the caravan stability game on the Bailey site, and the other information on that site, are the results from the bath study.

Interestingly it does make a reference if i recall correctly, to caravan weight, more weight can lead to increased instability. Also the 7% nose weight guide is mentioned.

Rather conflicts with your comments re the 85%/7% being out dated?

Quote from bath study

1/ "Yaw inertia is a measure of how far weight is from the centre of gravity, which in this case is across the caravan axle. Reducing the overall weight of the trailer will reduce Yaw inertia and concentrating that weight near the mid-axle point will greatly reduce Yaw inertia."

2/ "It is also recommended that there is enough weight in front of the axle to achieve a nose weight that is as high as allowed by the vehicle manufacture (7% of the caravan weight) "

]http://www.towingstabilitystudies.co.uk/stability_studies.htm

http://www.towingstabilitystudies.co.uk/stability_studies.htm[/quote
The statement ".... as allowed by the vehicle manufacture (7% of the caravan weight)" is a contradiction in itself as the limits specified by the vehicle manufacturer are never 7%. The manufacturers always specify an absolute value, never a percentage.

 

[Lutz]

ps: The 7% figure that you quote is on a Bailey's website, not one of the University of Bath. I seriously doubt whether the Bath researchers would ever have made a 7% recommendation. It was obviously dreamed up by someone at Bailey's, based on convention.

Also, it should be noted that the Bath studies were not carried out using state-of-the-art equipment. The towcar did not have TSP (Trailer Stability Program), nor did the trailer have an electronic stabiliser so, under those circumstances, the 85% recommendation is legitimate. However, with one or both of these features, 85% would be extremely conservative.

 

[xtrailman]

Lutz

If you look at the link, all my cut and paste comments are on that site.

Bath and bailey worked together on the project.

The statements are not mine but as far as i can see, are those of the bath researches.

The term " you can't have your cake and eat it" springs to mind.

 

[Lutz]

I can only repeat that the actual technical report (THE DYNAMICS OF TOWED VEHICLES, An experimental study into caravan snaking

Final year project submitted by Christopher J Killer for the degree of MEng of the University of Bath, 23 May 2003) makes no mention of 7% noseweight nor of an 85% weight ratio recommendation, so any reference to these figures are additions made by Baileys without scientific basis.

 

[Zafiral]

As Bailey only rate the caravans to have 100kg nose weight, it is not possible to have 7% on any (Bailey) caravan over 1428kg regardless of the towcar......

 

[Rob_374420349]

Hi Guys

Sorry I have not replied sooner,I have had lots of advise to look at and today a friend of mine towed my van with his Landcruiser and it towed fine even up to 60 mph in windy conditions but his car is a lot heavier than my Santa Fe.When we got back we checked my nose weight again with the built in gauge that Elddis fit to most of their new vans and found that it reads 75kg but when I used a seperate nose weight gauge under the hitch it then reads 65kg and my car ir rated to 88kg,it seems that I need to put more items in my front locker to get nearer to the 88kg of my car and then I need to try again and see if the outfit is more stable ? most advise given above has mentioned running at as close to the max as possible so fingers crossed this will sort my problem and the morale is never trust a built in nose weight gauge.I will add another message once I have tried this and let everyone know if its good news.Thanks again for all the help

ok Rob

 

[Dave_374330759]

If the built-in nose weight gauge is in the jockey wheel then you'll get a bit of variance in the reading, depending whether the jockey wheel is pointing backwards or forwards and it'll give a slightly different reading as it's not actually at the towball end of the chassis either. Adjust your towball weight by shifting stuff around until you measure 85-88kg at the towball using a bathroom scale and broom stick. Then check the jockey wheel gauge reading (take the scale away first) - this'll be the measurement to use in future when you are loading the van. It doesn't actually matter what it reads providing it's repeatable and can be referred back to the bathroom scale measurement at the towball. Looks like you can get an extra 20kg at the ball which should make a hell of a difference to your stability.

 

[Ianofwilts]

I am always surprised at how quickly what seems to be a simple request for help turns into a heated or possibly quite warm debate. Rather than attacking each other with a holier than thou approach how about helping the requester with our own experiences and let them make an a newly informed decision. Lets not sit in judgement, lets help.

Wilts Ian

 

[ProfJohnL]

I am always surprised at how quickly what seems to be a simple request for help turns into a heated or possibly quite warm debate. Rather than attacking each other with a holier than thou approach how about helping the requester with our own experiences and let them make an a newly informed decision. Lets not sit in judgement, lets help.

Wilts Ian

Hello Ian,

You may not believe it but I tend to agree with the concept of your post, BUT, you must remember that many of the questions posted are from new people to caravanning, and it is sadly human nature to see something in print and to believe it. So if some blatantly says they tow at 65mph and don't make it obvious that they know they should only be doing 60, the new caravanner may go away with the wrong impression about what is legal.

Posters on the forum should be aware that what they write may influence others, and if what they write suggests an illegal practice then they are certainly morally culpable. The sites use of nicknames to afford anonymity, is not a licence to encourage unsafe or illegal practices. It is also the case that if a reader feels they have been misled or damaged then in some circumstances the forum owners may be obliged to supply contributors details in pursuance of legal action.

 

[xtrailman]

Ian

Unfortunately while trying to help Rob, one is often accused of giving misleading information.

Often the CC guide of 85% is rubbished.

Often the NCC 7% nose guide is rubbished also.

Then we have the preacher, banging away at speeding.

So the thread is often steered away from the original topic.

If you look at post no3 i have suggested more nose weight, although the tow car has a lower nose weight than i imagined, Rob is trying more nose weight next time out.

You must remember that Rob is not a novice, so it is not easy to offer alternatives that he has not already tried.

 

[Gafferbill]

The point of nose weight being as high as possible within the design limits of the caravan hitch and the car's towbar, is to add weight to the rear axle of the tow car.

The rear axle of the tow car has to be secure on the road so that it can resist the lateral forces transmitted through the towbar that are present as the caravan becomes unstable.

Rob can make his outfit more stable by adding heavy items to the rear of his towcar with a compensatory increase in rear tyre pressure.