Carrying Adult size bikes in / on a Caravan

[JTQ]

Hello Darranna,

The tow bikes will broadly balance each other out, But is does increase the caravans moment of inertia, so it will also be necessary to ensure that as much luggage and other items are loaded as close as possible to the axle to claim back some of the Yaw inertia.

.

How is it possible to "claim back some of the Yaw inertia" ?

Surely with masses distributed away from the centre of yaw the polar moment of inertia gained from that is there and adding mass anywhere else can never diminish that value, only add further to it?
Whilst vans are designed with end bathrooms with masses associated, it is misleading to compare this with concentrated quite high masses like e-bikes hung out over the rear body work.
The moment of inertia is ruled by the square of the displacement of the mass from the centre of yaw and here the bikes are out beyond the bodywork.
What increasing the polar moment of inertia will do is lower the natural frequency of yaw, that is fundamental, plus it makes encountering it and with it instability more likely. Bikes on the rear can be "tolerable" but never be as safe as without doing so.

 

[ProfJohnL]

...How is it possible to "claim back some of the Yaw inertia" ?

Surely with masses distributed away from the centre of yaw the polar moment of inertia gained from that is there and adding mass anywhere else can never diminish that value, only add further to it?
Whilst vans are designed with end bathrooms with masses associated, it is misleading to compare this with concentrated quite high masses like e-bikes hung out over the rear body work.
The moment of inertia is ruled by the square of the displacement of the mass from the centre of yaw and here the bikes are out beyond the bodywork.
What increasing the polar moment of inertia will do is lower the natural frequency of yaw, that is fundamental, plus it makes encountering it and with it instability more likely. Bikes on the rear can be "tolerable" but never be as safe as without doing so.

Its not a question of adding other masses, They are already there in teh form of other payload items. If they are distributed throughout the caravan they will also introduce greater yaw inertia. So by fitting the bikes as I suggested which I agree and do allude will add to the inertia, to compensate, if some of the other payload items are relocated nearer the will axle, their effect will reduced and thus "claim back some of the Yaw inertia"

I disagree emphatically with your point about it being misleading to compare the mass of bike with structural mass. I would venture to suggest that the mass of a toilet with its tanks of liquid would have a very similar effect., The bottles of soap and shampoo, towels, and all the other paraphernalia of a bathroom are quite likely to exceed the 20Kg suggests by the OP.

I in no way suggested carrying the bikes would have no effect, quite the contrary I expressed the need for greater care.

I do agree with your point that by adding these masses will reduce the frequency of oscillation, but by increasing the mass there will be less tendency for system to respond to impact type forces for momentary bow waves, and side winds. Don't forget that the side area of the caravan isn't changing so side winds and bow waves are not going to exert any greater force to try and unsettle the caravan, so with more mass it will move less for the given disturbances. I therefore conclude it is not an automatic given that adding such masses will increase the tendency to wards instability - especially if I as suggested as much of the other payload can be concentrated near the axle.

But in all of this, if an addition 20kg on the rear is going to make the the caravan want to throw itself off f the road, I wold be very suspicious about the stability of the outfit without the added bikes, it must already be extremely twitchy.

 

[JTQ]

But in all of this, if an addition 20kg on the rear is going to make the the caravan want to throw itself off f the road,
Read more at https://www.practicalcaravan.com/forum/general/55257-carrying-adult-size-bikes-in-on-a-caravan#Rb72yco1yuMu7TXd.99

It was not 20 kgs added but two e-bikes of 20 kgs each plus some mass for the rack to carry them, so unlikely to be sub 50 kgs.
Very importantly that masses affect on stability is driven by the square of its displacement from the centre of yaw; 50 kgs displaced beyond the caravan will have I suggest a very significant effect.

 

[WoodlandsCamper]

Have people seen this video?

https://www.youtube.com/watch?v=PFzrWHTG5e8

 

[Darranna]

Have people seen this video?

Thanks for posting the video, but all it really proves is that if you go to extremes you have problems.
I'd have preferred to see the video with weights even spread throughout the model, rather than just the ends, which will obviously give a more dramatic effect.

 

[Craigyoung]

Same here , that was showing all the wait put on the back which isnt what any sensible person would do ! no wonder it was going out of control !

 

[ProfJohnL]

But in all of this, if an addition 20kg on the rear is going to make the the caravan want to throw itself off f the road,
Read more at https://www.practicalcaravan.com/forum/general/55257-carrying-adult-size-bikes-in-on-a-caravan#Rb72yco1yuMu7TXd.99

It was not 20 kgs added but two e-bikes of 20 kgs each plus some mass for the rack to carry them, so unlikely to be sub 50 kgs.
Very importantly that masses affect on stability is driven by the square of its displacement from the centre of yaw; 50 kgs displaced beyond the caravan will have I suggest a very significant effect.

I do not quibble with the mathematics of Yaw inertia, but it isn't that simple, becasue the the arrangement I have suggested has 1 bike at either end of the caravans body work. If the caravan were acting with just a circular motion about its main axle then the basic equation would be pretty fair, but there is a very significant difference with a caravan being towed, the front of the caravan is constrained by the the tow coupling and so it wont swing around the caravan wheel but will tend to swing around the tow coupling. Consequently the front bike will far lees contribution to the yaw forces

I know it looks as though I'm arguing that end loading is fine, I am not going that far. What I am trying to do is to show is that its not as black and white as most UK commentators make out, there is some scope for end loading providing it is done with care and consideration of the factors involved. Thousands of continental caravans use it, and they must face very similar issues to UK caravanners.

 

[Martin24]

WC, thanks for trying but we're flogging a couple of dead horses here, not worth the breath.

 

[JTQ]

posting removed

 

[ProfJohnL]

Hello again Darranna,

You may have gathered that "end loading" is a contentious issue for some. I'm not ignoring the dangers with my advice, but I am trying to be realistic and practical, and I believe that through your answers you have demonstrated a healthy understanding of the issues involved.

The video clip of the model has been around for several years now, and it is quite alarming to the untrained eye, When it was first shown like you I immediately spotted the that the load distribution was not a fair representation of real life. Although in detail it is technically not a true analogue it does drive home to most observers the reason to avoid end loading, and to that end (excuse the pun) it may well have saved some caravanners from having a problem.

The general advice is don't end load if you can avoid it, but if you can't avoid it then you need to exercise care and be aware of the instability issue.

The fact is I have towed many different caravans often fresh from a manufacturer or dealer with no additional pay load, and many have excessively large nose loads which needed to be trimmed out. I used to carry a number of containers that I could fill with water and I would use these usually placed at the back of the caravan to redress any excess nose load.

In many case I needed to use up to 20L of water but in a few cases I needed use close to 40L of water (that's 40kg) placed (and secured) at the rear of the caravan. At no time did I experience instability problems.

 

[Parksy]

Having read through this topic and seen the various advice that's been offered in good faith, I think that now might be a good time to ask that all forum members remain polite and objective toward each other.
Nobody has broken any rules, and this comment isn't directed at anybody, but it's easy to feel a bit put out if some of the advice seems to be disregarded or dismissed.
This can sometimes lead to hastily typed comments that could have benefitted from a moments forethought.
Many Thanks

 

[Raywood]

I am not sure there is a good answer to this question as to me the best place for bikes is on the car roof. As the Prof says mounting on the rear is possible but you could have stability issues. The other problem is the weight of the bikes. If you take the 40 kg weight of these plus the weight of the bracket you have taken a very large chunk out of your loading allowance and could easily be overweight when everything else is loaded inside. You would need to check the weight you carry and travel light I think.
You could put the bikes in the caravan which at least saves the weight of the mounting bracket, but risks internal damage, unless you find an easy and secure place to store them.
It might be possible to increase the MTPLM which I think will be needed to overcome the weight problem if this has not be done already.
Mounting 40 kg plus a bracket on the towbar will almost certainly leave you overweight there.
Sorry for the pessimistic reply but there is no easy answer to this one.

 

[Darranna]

WC, thanks for trying but we're flogging a couple of dead horses here, not worth the breath.

Thank you for your input

 

[Darranna]

Thousands of continental caravans use it, and they must face very similar issues to UK caravanners.

It's specifically because of the point you make here, that there must be a logical solution.

My wife and I were in Germany a couple of weeks ago any nearly all the vans there have bike racks, some with two electric bikes on the front some with them on the rear. Ok I accept that electric bikes haven't yet caught on as much over here as they have in mainland Europe, but its only a matter of time.

I agree with some of the points regarding the best place to mount the bike is on the roof, but thats simply not possible with my car. And no, I'm not about to change my car, I will spend less than 5% of my motoring time towing the van so its simply not an option.

The other viable option is to carry the bikes inside the van, but there is a good chance the interior would get damaged and then, what do I do with the bikes in the evening, drag them back in the van with us, not very practical is it?

So I'm sure there is a solution, I clearly don't know what it is, but Swift are starting to understand the need for a cycle rack, hence them including them as an option it on their more recent models, I also accept that these are not designed to accommodate a 20 KG bike but the mounting would be good enough to support one bike at least.
I understand why some people scoff at the fact I'm trying to resolve an issue that is specific to my own caravanning requirements, by coming up with a solution that may not be what others would consider, thats fine, I get that. But I'm not trying to convert anyone to buy an Electric bike or any sort of bike for that matter. I'm simply asking a question that clearly doesn't come up very often.

 

[KeefySher]

Lateral thinking here :evil: :evil: stay with it....

Over the years have carried bikes on roof racks, tow bars, on top of a trailer, on rack on rear door of MH. Also fitted roof box on rear of MH vertically on a ski rack.

Recently we changed the tow car from a saloon to a big 4x4, and have so far done more cycling than in a long time. There are 3 bikes to carry btw.

We carry the bikes on the roof of the new tow car and load using the caravan steps when towing the caravan.

When not using the caravan we use the 3 bike carrier from Thule, the velocompact 927 on the tow bar. There is a 2 bike version available, the 925. https://www.thule.com/en-gb/gb/bike-rack/towbar-bike-racks/thule-velocompact-925-_-925

We collapse the velocompact on put in the caravan over the axle when we want to explore and attach to the tow bar for ease of loading, taking the roof bar / bike carrier combination off the car roof if required and storing in the awning / under the caravan.

At home, have part converted the garage which gives us a dry store for sports gear. In here we place the velocompact on the floor, a space that ordinarily gets full of junk thrown in as it is a space (not an uncommon issue I suggest). The bikes are then put on the velocompact and using the tie bars secured in place.

So, if the 2 bike 925 is loaded with the bikes in your caravan, the whole assembly becomes a 'box', that I would hazard a guess would be very stable, it certainly is when we place the empty unit in the caravan. Maybe some foam padding on edges would reduce any rubbing / impact?

You then have the ability to transport your bikes by your car with or without caravan and add to their use.

The velocompact collapses to fit in the boot of the car if required, too

The Thule gear is excellent. By shopping around and finding vouchers you can get one interest free over 12 months from a South Wales stockist, that also gives you a credit score enhancement, and considerably lower price than list. e.g. we pay £25/month over 12 months for our unit that has a RRP of £445, saving £145.

Food for thought?

 

[Darranna]

Hi thanks for taking the time to post.

Its something else we have considered, we already have a Thule 925 that we used to recently transport the bikes to South Wales and had planned to use it to take the bikes to Germany, although that plan got scuppered.

I don't think there is room in our van to sit this on the floor, although I will try it at the weekend.

Another way we had thought of doing it would to buy a LAS Mount
https://www.amazon.co.uk/dp/B0023RQING/ref=wl_it_dp_o_pC_S_ttl?_encoding=UTF8&colid=3FU7WDN77GUMR&coliid=I244R5X10RWYIU
and fit that to the front A Frame and then fit the Thule 925 to that, but it would add quite a lot of weight directly on the nose.

Please do keep these ideals coming

 

[KeefySher]

Do your e bikes have the fold in pedals, easy turn handle bars, quick release wheels / batteries?

Recently on a CAMC site there was a mega MH, Concorde jobby that had a rear garage. The owners had every possible toy ever invented for a MH by the look of it. Amongst those were 2 e bikes that were duly removed from the full garage on Thule / Fiamma bike ramps; each e bike had fold in pedals, turned handle bars so they aligned with the frame, removable batteries. Providing a very narrow width 'box' that may be making to the space in your caravan between the seats in the lounge area (sorry not seen your particular layout) suitable to house the bikes. The bikes were paraded out each morning, assembled, stood on fancy stands. Each evening put away, never ridden!!!

How about a couple of cheap u channel type bike carriers screwed to a plank of wood, then strap the upper parts of the bikes together inside your caravan.

Remove the front wheels and use the basic carriers that fit in the floor of a people carrier / estate car.

Cut down a T track roof bar into 3 small pieces, add 2 basic cycle carriers staggered to fit the bikes in the space, as you would to fit 7 bikes on a 7 seat car, to make a base that you then pad out as required to support.

Is this your layout: https://www.marquisleisure.co.uk/caravans/stock-item/swift-charisma-535-32585

Put the bikes in line astern between the lounge seats for bike 1. Bike 2 goes front wheel turned in the area next to the bed. Use cut down basic bike carriers ( https://www.amazon.co.uk/UNIVERSAL-BICYCLE-CARRIER-UPRIGHT-MOUNTED/dp/B00SHHB9OO )mounted on timber batons to fit the gaps with padding at ends. Strap to supports like the kitchen/bedroom post.

I struggle to understand how difficult your solution has to be. Adapt, improvise, overcome. There are myriad cycle carrier parts available, just use them in a different way.

Change your caravan to a Swift Base Camp that the furniture folds away leaving a hole to fill with junk like bikes??

 

[Raywood]

If you are thinking of the LAS mount I would check the nose weight of the caravan now and see if there is room to manouvre to allow this to be used. Without knowing what car you have we do not know the noseweight limit, but if it is high you also need to know that for the towbar and hitch as they might be less, and you should then see if it is viable.
Looking at the photo on the advert though it is fitted to a continental caravan with an exposed A frame. The caravan you have will have a covered one, but that should be relatively easy to remove if you are happy to do that..

 

[KeefySher]

If you are thinking of the LAS mount I would check the nose weight of the caravan now and see if there is room to manouvre to allow this to be used. Without knowing what car you have we do not know the noseweight limit, but if it is high you also need to know that for the towbar and hitch as they might be less, and you should then see if it is viable.
Looking at the photo on the advert though it is fitted to a continental caravan with an exposed A frame. The caravan you have will have a covered one, but that should be relatively easy to remove if you are happy to do that..

At post 43079 the OP said:

'The tow car is a Renault Laguna Coupe with a maximum Permissible nose weight of 75 KGs'

Bit on the low side me thinks for the LAS mount and bikes

 

[Darranna]

Do your e bikes have the fold in pedals, easy turn handle bars, quick release wheels / batteries?

Recently on a CAMC site there was a mega MH, Concorde jobby that had a rear garage. The owners had every possible toy ever invented for a MH by the look of it. Amongst those were 2 e bikes that were duly removed from the full garage on Thule / Fiamma bike ramps; each e bike had fold in pedals, turned handle bars so they aligned with the frame, removable batteries. Providing a very narrow width 'box' that may be making to the space in your caravan between the seats in the lounge area (sorry not seen your particular layout) suitable to house the bikes. The bikes were paraded out each morning, assembled, stood on fancy stands. Each evening put away, never ridden!!!

How about a couple of cheap u channel type bike carriers screwed to a plank of wood, then strap the upper parts of the bikes together inside your caravan.

Remove the front wheels and use the basic carriers that fit in the floor of a people carrier / estate car.

Cut down a T track roof bar into 3 small pieces, add 2 basic cycle carriers staggered to fit the bikes in the space, as you would to fit 7 bikes on a 7 seat car, to make a base that you then pad out as required to support.

Is this your layout: https://www.marquisleisure.co.uk/caravans/stock-item/swift-charisma-535-32585

Put the bikes in line astern between the lounge seats for bike 1. Bike 2 goes front wheel turned in the area next to the bed. Use cut down basic bike carriers ( https://www.amazon.co.uk/UNIVERSAL-BICYCLE-CARRIER-UPRIGHT-MOUNTED/dp/B00SHHB9OO )mounted on timber batons to fit the gaps with padding at ends. Strap to supports like the kitchen/bedroom post.

I struggle to understand how difficult your solution has to be. Adapt, improvise, overcome. There are myriad cycle carrier parts available, just use them in a different way.

Change your caravan to a Swift Base Camp that the furniture folds away leaving a hole to fill with junk like bikes??

Thank you for taking the time to reply.

Your solution has previously been mentioned and we did consider it, but it's simply not practical.

The interior will get damaged dragging two 20kg bikes in and out, the bikes do not have folding pedals or quick folding bars, they do have removable batteries but that doesn't help with space, just weight. And what would we do with them in the evenings or if we happen to go out during the day without the bikes.

 

[Darranna]

Out of interest do Caravan door widths vary much?

I've been out and measured mine and its only 49 cms which does seem narrow, but I have nothing to compare it to :dry:

 

[KeefySher]

Do your e bikes have the fold in pedals, easy turn handle bars, quick release wheels / batteries?

Recently on a CAMC site there was a mega MH, Concorde jobby that had a rear garage. The owners had every possible toy ever invented for a MH by the look of it. Amongst those were 2 e bikes that were duly removed from the full garage on Thule / Fiamma bike ramps; each e bike had fold in pedals, turned handle bars so they aligned with the frame, removable batteries. Providing a very narrow width 'box' that may be making to the space in your caravan between the seats in the lounge area (sorry not seen your particular layout) suitable to house the bikes. The bikes were paraded out each morning, assembled, stood on fancy stands. Each evening put away, never ridden!!!

How about a couple of cheap u channel type bike carriers screwed to a plank of wood, then strap the upper parts of the bikes together inside your caravan.

Remove the front wheels and use the basic carriers that fit in the floor of a people carrier / estate car.

Cut down a T track roof bar into 3 small pieces, add 2 basic cycle carriers staggered to fit the bikes in the space, as you would to fit 7 bikes on a 7 seat car, to make a base that you then pad out as required to support.

Is this your layout: https://www.marquisleisure.co.uk/caravans/stock-item/swift-charisma-535-32585

Put the bikes in line astern between the lounge seats for bike 1. Bike 2 goes front wheel turned in the area next to the bed. Use cut down basic bike carriers ( https://www.amazon.co.uk/UNIVERSAL-BICYCLE-CARRIER-UPRIGHT-MOUNTED/dp/B00SHHB9OO )mounted on timber batons to fit the gaps with padding at ends. Strap to supports like the kitchen/bedroom post.

I struggle to understand how difficult your solution has to be. Adapt, improvise, overcome. There are myriad cycle carrier parts available, just use them in a different way.

Change your caravan to a Swift Base Camp that the furniture folds away leaving a hole to fill with junk like bikes??

Thank you for taking the time to reply.

Your solution has previously been mentioned and we did consider it, but it's simply not practical.

The interior will get damaged dragging two 20kg bikes in and out, the bikes do not have folding pedals or quick folding bars, they do have removable batteries but that doesn't help with space, just weight. And what would we do with them in the evenings or if we happen to go out during the day without the bikes.

Why would you drag the bikes? do the wheels not turn? Use a ramp like wot Thule and Fiamma advise when loading e bikes onto their tow bar and MH garage cycle fitments?? Lock them to a caravan wheel? Put them on the 975 either on the car tow ball, or on the ground with the lock on perhaps the hitch lock ball attached too? Accept that caravan sites are generally not thiefs playgrounds and lock them together, the same as you might if using a rear mounted rack inbuilt on a caravan or MH.

 

[Darranna]

Do your e bikes have the fold in pedals, easy turn handle bars, quick release wheels / batteries?

Recently on a CAMC site there was a mega MH, Concorde jobby that had a rear garage. The owners had every possible toy ever invented for a MH by the look of it. Amongst those were 2 e bikes that were duly removed from the full garage on Thule / Fiamma bike ramps; each e bike had fold in pedals, turned handle bars so they aligned with the frame, removable batteries. Providing a very narrow width 'box' that may be making to the space in your caravan between the seats in the lounge area (sorry not seen your particular layout) suitable to house the bikes. The bikes were paraded out each morning, assembled, stood on fancy stands. Each evening put away, never ridden!!!

How about a couple of cheap u channel type bike carriers screwed to a plank of wood, then strap the upper parts of the bikes together inside your caravan.

Remove the front wheels and use the basic carriers that fit in the floor of a people carrier / estate car.

Cut down a T track roof bar into 3 small pieces, add 2 basic cycle carriers staggered to fit the bikes in the space, as you would to fit 7 bikes on a 7 seat car, to make a base that you then pad out as required to support.

Is this your layout: https://www.marquisleisure.co.uk/caravans/stock-item/swift-charisma-535-32585

Put the bikes in line astern between the lounge seats for bike 1. Bike 2 goes front wheel turned in the area next to the bed. Use cut down basic bike carriers ( https://www.amazon.co.uk/UNIVERSAL-BICYCLE-CARRIER-UPRIGHT-MOUNTED/dp/B00SHHB9OO )mounted on timber batons to fit the gaps with padding at ends. Strap to supports like the kitchen/bedroom post.

I struggle to understand how difficult your solution has to be. Adapt, improvise, overcome. There are myriad cycle carrier parts available, just use them in a different way.

Change your caravan to a Swift Base Camp that the furniture folds away leaving a hole to fill with junk like bikes??

Thank you for taking the time to reply.

Your solution has previously been mentioned and we did consider it, but it's simply not practical.

The interior will get damaged dragging two 20kg bikes in and out, the bikes do not have folding pedals or quick folding bars, they do have removable batteries but that doesn't help with space, just weight. And what would we do with them in the evenings or if we happen to go out during the day without the bikes.

Why would you drag the bikes? do the wheels not turn? Use a ramp like wot Thule and Fiamma advise when loading e bikes onto their tow bar and MH garage cycle fitments?? Lock them to a caravan wheel? Put them on the 975 either on the car tow ball, or on the ground with the lock on perhaps the hitch lock ball attached too? Accept that caravan sites are generally not thiefs playgrounds and lock them together, the same as you might if using a rear mounted rack inbuilt on a caravan or MH.

Not entirely the sarcastic tone is nessasary hmy:

If I were buying the bikes today, I would have bought folding bikes and so the issue I am now faced with would not exist.
I obviously didn't literally drag, but I think you know that.

I don't have excesses of money to waste and I therefore have to look after the things I do have, if that's to much of a challenge for people to realise that's hardly my fault.

I always thought that forums like this were to assist one another to discover things they didn't already know, apparently this one is mainly here to poke fun at people trying to achievement so I thing that hasn't been done before.

That's fine I now know what to expect!

 

[Parksy]

Do your e bikes have the fold in pedals, easy turn handle bars, quick release wheels / batteries?

Recently on a CAMC site there was a mega MH, Concorde jobby that had a rear garage. The owners had every possible toy ever invented for a MH by the look of it. Amongst those were 2 e bikes that were duly removed from the full garage on Thule / Fiamma bike ramps; each e bike had fold in pedals, turned handle bars so they aligned with the frame, removable batteries. Providing a very narrow width 'box' that may be making to the space in your caravan between the seats in the lounge area (sorry not seen your particular layout) suitable to house the bikes. The bikes were paraded out each morning, assembled, stood on fancy stands. Each evening put away, never ridden!!!

How about a couple of cheap u channel type bike carriers screwed to a plank of wood, then strap the upper parts of the bikes together inside your caravan.

Remove the front wheels and use the basic carriers that fit in the floor of a people carrier / estate car.

Cut down a T track roof bar into 3 small pieces, add 2 basic cycle carriers staggered to fit the bikes in the space, as you would to fit 7 bikes on a 7 seat car, to make a base that you then pad out as required to support.

Is this your layout: https://www.marquisleisure.co.uk/caravans/stock-item/swift-charisma-535-32585

Put the bikes in line astern between the lounge seats for bike 1. Bike 2 goes front wheel turned in the area next to the bed. Use cut down basic bike carriers ( https://www.amazon.co.uk/UNIVERSAL-BICYCLE-CARRIER-UPRIGHT-MOUNTED/dp/B00SHHB9OO )mounted on timber batons to fit the gaps with padding at ends. Strap to supports like the kitchen/bedroom post.

I struggle to understand how difficult your solution has to be. Adapt, improvise, overcome. There are myriad cycle carrier parts available, just use them in a different way.

Change your caravan to a Swift Base Camp that the furniture folds away leaving a hole to fill with junk like bikes??

Thank you for taking the time to reply.

Your solution has previously been mentioned and we did consider it, but it's simply not practical.

The interior will get damaged dragging two 20kg bikes in and out, the bikes do not have folding pedals or quick folding bars, they do have removable batteries but that doesn't help with space, just weight. And what would we do with them in the evenings or if we happen to go out during the day without the bikes.

Why would you drag the bikes? do the wheels not turn? Use a ramp like wot Thule and Fiamma advise when loading e bikes onto their tow bar and MH garage cycle fitments?? Lock them to a caravan wheel? Put them on the 975 either on the car tow ball, or on the ground with the lock on perhaps the hitch lock ball attached too? Accept that caravan sites are generally not thiefs playgrounds and lock them together, the same as you might if using a rear mounted rack inbuilt on a caravan or MH.

Not entirely the sarcastic tone is nessasary hmy:

If I were buying the bikes today, I would have bought folding bikes and so the issue I am now faced with would not exist.
I obviously didn't literally drag, but I think you know that.

I don't have excesses of money to waste and I therefore have to look after the things I do have, if that's to much of a challenge for people to realise that's hardly my fault.

I always thought that forums like this were to assist one another to discover things they didn't already know, apparently this one is mainly here to poke fun at people trying to achievement so I thing that hasn't been done before.

That's fine I now know what to expect!

I posted a request earlier for everyone to be polite and objective.
My request doesn't seem to have been heeded so I've edited the comment that was quoted above and edited the quote to remove the edgy comments.
Nobody should expect to receive barbed replies, even though it's becoming increasingly obvious that no advice offered so far which would comply with legal requirements seems to be acceptable.
Loading bicycles on to caravans has indeed been done many times before, but there's no point in receiving advice that would lead to overloading towing vehicle or caravan weight limits.

 

[otherclive]

I've been watching this thread with interest and I must say some posts have come up with some really good ideas for stowing the two large and inflexible bikes. But within the limitations of either the car or caravan the OP is unable to see them as feasible, but that's not the fault of those who have put forward ideas. There is a lot of years of caravan experience behind those who have contributed but still their suggestions aren't acceptable. I feel that other than having a customised fit to the caravans rear panel nothing would suffice. But I for one wouldn't even consider such a modification not on stability grounds. The fact that some newer Swift vans have such options means they were designed for it but I don't know what their rear bike carrier weight limits are. Having two large inflexible bikes hanging out over the rear and their vertical movement in response to road movements would require a substantial internal framework or else the caravans rear panel/seals could be damaged. I would not go down that route.
A point the OP makes about continental vans having two bikes on the A frame is valid. But when I had a continental van it was light on noseweight as it didn't have many of the fitments taken for granted over many years by UK owners. I.e. No heater, no battery, no hot water system, no oven, small fridge, small three burner job. When it had some of those bits fitted its noseweight went up.