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The road toad

Still people towing at 100%

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While browsing the forums and the members cars and vans I noticed a few scary combos with people towing at 100% of vehicle kerb weight!

Are they mad or oblivious of the dangers?

Surely any fool can see the dangers of the van trying to drive/control the car?

Beats me.

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My car has an unladen weight of around 2350Kg, it can legally tow 3500 Kg, much more than 100%, I don’t see a problem.

 

Having said that my caravan is 2000 Kg so well under 100%

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3 minutes ago, Borussia 1900 said:

My car has an unladen weight of around 2350Kg, it can legally tow 3500 Kg, much more than 100%, I don’t see a problem.

 

Having said that my caravan is 2000 Kg so well under 100%

Not sure the maximum tow wht is really intended for caravans.  A flat bed trailer lower than the car is probably as safe at 125% as a caravan with large frontal and side areas at 80 - 90%.    In a previous life I towed some fairly heavy trailers  and they always seemed very stable although stopping distance meant paying attantion to the road and keeping speeds sensible.

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It seems to me that what you can legally tow and what is safe to tow are two separate issues and the good old 85% rule is worth adhering to.

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The advice from both large clubs and the National Caravan Council is that for beginners the MTPLM of the caravan should be 85% of the cars kerbside weight or less.

But all three of these major players agree that for experienced towers up to 100% is suitable.

 

This is due to the inherent instability of caravans due to their length, high centre of gravity and the high sides being caught by wind and turbulence.

 

I don't see an issue if experienced towers want to approach 100% with care but we have seen relatively new caravaners on here towing above 120% which is insane.

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23 minutes ago, The road toad said:

While browsing the forums and the members cars and vans I noticed a few scary combos with people towing at 100% of vehicle kerb weight!

Are they mad or oblivious of the dangers?

Surely any fool can see the dangers of the van trying to drive/control the car?

Beats me.

 

It's within NCC guidelines for experienced caravanners to tow up to 100% so I don't see what your issue is. I strongly support the 85% guideline for beginners and then let them make their own mind up once they're experienced.

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22 minutes ago, The road toad said:

While browsing the forums and the members cars and vans I noticed a few scary combos with people towing at 100% of vehicle kerb weight!

Are they mad or oblivious of the dangers?

Surely any fool can see the dangers of the van trying to drive/control the car?

Beats me.

Can you show a single piece of credible evidence to support your view?

If you want to embrace the supposed logic of ensuring that the caravan should not drive/control the car you should refer to the Actual Laden Weight of both and discount all HGVs whose trailers exceed the weight of the tractor unit.

 

Your logic has more holes than substance!

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25 minutes ago, The road toad said:

While browsing the forums and the members cars and vans I noticed a few scary combos with people towing at 100% of vehicle kerb weight!

Are they mad or oblivious of the dangers?

Surely any fool can see the dangers of the van trying to drive/control the car?

Beats me.

 

How do you know they are please?  Many of us might well be close or over 100% in theory but, as for myself and others, putting most of the loose weight in the car and very little in the van whilst ensuring we comply with the manufacturers limits mean that we are well under in reality despite, in my example a 2200 kg MTPLM  caravan with a similar kerb weight car.

 

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21 minutes ago, Eirrab said:

Not sure the maximum tow wht is really intended for caravans.  A flat bed trailer lower than the car is probably as safe at 125% as a caravan with large frontal and side areas at 80 - 90%.    In a previous life I towed some fairly heavy trailers  and they always seemed very stable although stopping distance meant paying attantion to the road and keeping speeds sensible.

In a previous life I’ve driven tank transporters + trailer + tank, well in excess of 100 tonnes. As long as you drive within the legal limits and your own capabilities I don’t see a drama.

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16 minutes ago, Stevan said:

If you want to embrace the supposed logic of ensuring that the caravan should not drive/control the car you should refer to the Actual Laden Weight of both and discount all HGVs whose trailers exceed the weight of the tractor unit.

 

 

 

The advice from the Caravan and Camping Club, The Caravan Club and the National Caravan Council all use MTPLM vs kerbweight to give a level playing field and a factor of safety as in theory  it's the worse case.

Many insurers now have a 100% clause when towing caravans.

 

HGV's are somewhat different as the "Nose Weight" the trailer exerts on the tractor unit is many many times higher as a percentage than a car/caravan.  If you moved the the axles on a caravan to the back of the caravan then you would get the same effect.

You just have to look at some of the larger US 5th wheel caravans with axles at the back, the noseweights can be over a ton.

Edited by logiclee
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Very much like a tank transporter though 😜

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1 hour ago, The road toad said:

While browsing the forums and the members cars and vans I noticed a few scary combos with people towing at 100% of vehicle kerb weight!

Are they mad or oblivious of the dangers?

Surely any fool can see the dangers of the van trying to drive/control the car?

Beats me.

 

I have noticed more and more TA being towed with combinations that I have thought that is pushing it last week was a Swift Challenger towed by a Ssangyong Korando  and this week a Swift 645 towed by the same on neighbour pitches

 

Dave

Edited by CommanderDave

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33 minutes ago, The road toad said:

It seems to me that what you can legally tow and what is safe to tow are two separate issues and the good old 85% rule is worth adhering to.

The 85% quoted is NOT a rule, it has no legal value whatsoever!!!!!

It is  a number dragged out of thin air many moons ago when cars were a lot different in their performance.

It is a guide , however, for new and inexperienced to towing.

 

Providing the loading is correct and the driver is happy with the way the combination handles, and the weights are within the car and van limits there is no problem towing at 100%

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30 minutes ago, logiclee said:

 

The advice from the Caravan and Camping Club, The Caravan Club and the National Caravan Council all use MTPLM vs kerbweight to give a level playing field and a factor of safety as in theory  it's the worse case.

Many insurers now have a 100% clause when towing caravans.

 

HGV's are somewhat different as the "Nose Weight" the trailer exerts on the tractor unit is many many times higher as a percentage than a car/caravan.  If you moved the the axles on a caravan to the back of the caravan then you would get the same effect.

You just have to look at some of the larger US 5th wheel caravans with axles at the back, the noseweights can be over a ton.

None of this is news to me, but I remain to see a shred of credible evidence that supports the conventional 100% ratio.

There is plenty of anecdotal evidence to show that ratios of in excess of 100% (by whatever method you calculate it) sometimes work, and  ratios of less than 85 sometimes fail catastrophically.  

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1 hour ago, Borussia 1900 said:

My car has an unladen weight of around 2350Kg, it can legally tow 3500 Kg, much more than 100%, I don’t see a problem.

 

Having said that my caravan is 2000 Kg so well under 100%

My Discovery 4 comes in at just under 2600kg in its vest and pants with a tow limit of 3500kg.

 

I wouldn't pull something the size and shape of caravan at that weight though, maybe a flat bed tri axle loaded with crates of Hob Goblin.

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The other issue mentioned in the OP is brakes. Caravan brakes are designed to retard the caravan at its MTPLM. The car brakes retard the car. if you ever have the misfortune to tow a caravan with the brakes not working you will know this.

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The way I interpret this is the car manufacturers towing limit is based on the power train, it does not consider the safety of the outfit as a whole.

 

Dont ask me for evidence, I have none.  Just using common sense tells me that the heavier the towed vehicle is, the more chance there is of the tail wagging the dog.

 

Comparing a car with a tractor unit is total nonsense.  

 

I know there is a lot more to consider in achieving a stable outfit.  But the weight of a high sided, highish centre of gravity caravan in comparison to the towing vehicle has got to be number 1.

 

John 

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3 hours ago, The road toad said:

While browsing the forums and the members cars and vans I noticed a few scary combos with people towing at 100% of vehicle kerb weight!

Are they mad or oblivious of the dangers?

Surely any fool can see the dangers of the van trying to drive/control the car?

Beats me.

I can only assume from this and other recent posts that if you saw a car and caravan combination over 85% with 4 dogs on board you would go into a total melt down! 🐕🐩🐕🐩😂

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3 hours ago, JCloughie said:

The way I interpret this is the car manufacturers towing limit is based on the power train, it does not consider the safety of the outfit as a whole.

 

 

You're right. The towing limits are based on what the manufacturer has deemed technically safe at speeds at which the trailer or caravan is intended to be towed under ideal road and weather conditions. Hence the max. permissible speed that he is required to specify in the Certificate of Conformity.

It does not make any provisions for the competence or lack thereof of the idiot behind the wheel, nor does it take into account less than ideal towing conditions, because the manufacturer can have no knowledge of any such constraints..

 

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They may be towing at 100% of kerb weight but are they towing at over 85% of actual weight ?

 

 

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9 hours ago, The road toad said:

While browsing the forums and the members cars and vans I noticed a few scary combos with people towing at 100% of vehicle kerb weight!

Are they mad or oblivious of the dangers?

Surely any fool can see the dangers of the van trying to drive/control the car?

Beats me.

 

 I accept it "beats" some, but there are others  of us that realise there is a lot more to towed unit stability than just a mass ratio.

The positive and negative attributes re towing stability of the tow car and of the trailer play similarly powerful roles in how successfully they interact.

It is simply not just a mass ratio that causes the trailer to control the car as claimed.

These include, but are not limited to: Centre of gravity of each, tow ball to axle overhang, tyre profile, tyre pressure,  tow vehicle wheel base, trailer axle location, nose weight and lateral stiffness of rear suspension in particular.

 

From this you can conclude there can easily be, and are some tow vehicles that are poor towers at 85%, whilst other vehicle being more capable above 85%.

It is no more that a rudimentary guide for beginners where no better information is available to them.

 

 

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So, just how does a casual glance at a quoted car & caravan title spit out a towing ratio? Weights vary wildly between makes and models! There are lightweights caravans that look heavy and heavyweight cars that look light. I have had more than one caravan-weight-expert question my choice on site, they all get the same answer. Legal and within the various organisations guidelines. 

 

Twin axle behind a BMW 5 series (92% match), now changed to a Volvo V90 (89% match). 

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Edited by GaryB1969

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9 hours ago, JCloughie said:

 

Dont ask me for evidence, I have none.  Just using common sense tells me that the heavier the towed vehicle is, the more chance there is of the tail wagging the dog.

 

 

I don't dispute that statement but I do not understand why this is seen by so many as one of, the main factors in caravan safety, when there are so many other factors involved. The fact that organisations like the CMC have embraced this idea carries no weight at all without them having published evidence to support it, large organisations are perfectly capable of being totally wrong!

I am guessing now, but I suppose that it is because 100% is such a cosy round number and it has such a simple (naïve?)  logic to it.

Cosy round numbers and naïve logic do not seem to me to be the best basis for a safety issue.

 

 

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12 hours ago, The road toad said:

While browsing the forums and the members cars and vans I noticed a few scary combos with people towing at 100% of vehicle kerb weight!

How do you know the percentage? Have you stopped them and put them on your portable scales? Do you carry reference tables of every possible combination of car and caravan? Or are you just making assumptions based on pre-conceived ideas?

Perhaps you would like to tell me the ratio of my combination:8FA31232-140B-458F-BD0F-BA4000F4372A.thumb.jpeg.6c95f914309fb581772696f0dbc3bc78.jpeg

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There was a lot of discussion with the CMC and CCC when the Bath University studies were done. I was a regional organiser for the CCC at the time, before the days of internet forums.  And although speed came out as the main factor for instability and not towing ratio it was concluded that basic physics applied to yaw inertia.

 

If for some reason a sudden direction change or mechanical failure introduced sudden yaw inertia then the ability of the tow vehicle to control that yaw inertia is directly affected by towing ratio. Sure loading also plays a major factor which is why the 85% for beginners and 100% recommendations were not only maintained but re-enforced.

 

I've towed way above 100% with other trailers and 97% with caravans and I don't see an issue with the 100% advice.

 

But we do see new caravaners on here wanting to tow above 100% with people giving the advice that they are legal and will be OK.  So people with limited technical knowledge and often just a few years of towing experience telling new caravanners they will be OK doing something that all the experts in industry and even sales do not recommend.

 

I think as a forum that's skating on thin ice.

 

 

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