Caravan Bike rack - Any advice

[Guest]

I wonder how much weight is on the back end of a caravan that has an end kitchen (cooker plus fridge loaded with food), or one with wardrobes at the rear with clothes in it? I’ve never had a rear mounted bike rack but I’ve certainly had caravans with end kitchens or wardrobes. 

[Stevan]

13 hours ago, JTQ said:

In fact hugely different, nothing but nothing, or all the loading you might try can't reduce the mass moment of inertia if there is 40 kgs mounted on the rear of a caravan.

Noseweight can be altered by loading, but that is just "balancing", not the very different moment of inertia issue, that is also a factor here.

 

1 hour ago, xtrailman said:

 

I beg to differ having owned both caravans .

And presently having towed for over 3 year's with a 40kg rear bike rack load.

And previously 6 years with a caravan that required around 30kg to the rear.

 

Have you actually towed with either?

There really is little point debating specifics!

Although much is known about how different factors affect the stability of caravans in theory, and some research has been done which shows that some of this theory carries over into the real world, virtually none has been done to try to understand how the different factors interact with each other.

The only real testing that seems to be done is by manufacturers whose sole interest is to show how safe their product is!

We have loads of anecdotal evidence, much of it contradictory, about what does, or does not make for a stable outfit, and all we have by way of conclusions is that certain practices tend to make outfits less stable and others tend to make them more stable, without any clear limits or deciding factors, while we simply have no agreed understanding at all about other factors.

Moment of inertia (High if the van is heavy at the ends, low if it is heavy in the middle) is known to be an issue once the van is swinging like a demented pendulum, but whether it makes any real difference in ordinary driving is a mystery!

Very little research has been done

[JTQ]

2 hours ago, xtrailman said:

 

I beg to differ having owned both caravans .

And presently having towed for over 3 year's with a 40kg rear bike rack load.

And previously 6 years with a caravan that required around 30kg to the rear.

 

Have you actually towed with either?

Quite where do you" beg to differ"?

Once there, the mass moment of inertia is there. Any balancing of that mass can only increase its magnitude.

 

2 hours ago, GaryB1969 said:

I wonder how much weight is on the back end of a caravan that has an end kitchen (cooker plus fridge loaded with food), or one with wardrobes at the rear with clothes in it? I’ve never had a rear mounted bike rack but I’ve certainly had caravans with end kitchens or wardrobes. 

 

The effect of masses on the mass moment of inertia, is dictated by the distance from the centre of swaying, squared.

 So  there is a real difference with 40 kgs of clobber within the van's rear, to overhung off the van's rear, where instability initiates as swing about the axle.

Even so some rear kitchen vans were indeed twitchy, and typically that layout has not been carried into many of the extra long vans.

You would be unwise to put 40 kgs of clobber say into a rear bed under locker, but doing so is far less detrimental than on a rear bike rack, as the distance to the axle is about half, so its impact just a quarter.

Edited February 18, 2021 by JTQ

[xtrailman]

I've also owned a caravan with end kitchen that you couldn't step into with out the caravan tipping, it had an ex works NW of 35kg.

 

The fact is caravans can come unbalanced from the start that's why loading is important, that's in practise not theory.

Those that criticise towing with rear bike racks in my experience are theorists who have never towed with one.

Edited February 18, 2021 by xtrailman

[Stevan]

2 minutes ago, xtrailman said:

I've also owned a caravan with end kitchen that you couldn't step into with out the caravan tipping, it had an ex works NW of 35kg.

 

The fact is caravans can come unbalanced from the start that's why loading is important, that's in practise not theory.

Those that criticise towing with rear bike racks in my experience are theorists who have never towed with one.

Absolutely, the fact that it can be made to work despite being theoretically wrong proves that the theories are not properly understood.

[xtrailman]

On 17/02/2021 at 09:53, KnausCol said:

ebikes on the back, golf clubs in the front? I hope you are considering your van's total personal payload as those items would take a large chunk out of what's available on a lot of vans.

 

I upgraded my caravan to allow for two bikes and rack at around 40kg total , rack is around 10kg, and 33kg for a mover.

[fred]

8 hours ago, xtrailman said:

 

I upgraded my caravan to allow for two bikes and rack at around 40kg total , rack is around 10kg, and 33kg for a mover.

You mean you sent some money and they sent you a new sticker with a different weight on it?

[KnausCol]

10 hours ago, xtrailman said:

 

I upgraded my caravan to allow for two bikes and rack at around 40kg total , rack is around 10kg, and 33kg for a mover.

So out of interest what is your MIRO and new MTPLM?

[xtrailman]

Was 1635kg, now 1700kg.

2 hours ago, fred said:

You mean you sent some money and they sent you a new sticker with a different weight on it?

 Cost me nothing bought the caravan new.

[KnausCol]

26 minutes ago, xtrailman said:

Was 1635kg, now 1700kg.

 Cost me nothing bought the caravan new.

Apologies xtrailman - got my wires crossed. I thought the weights conversation related to the OP but I see now it doesn't.

[David McIntyre]

If I was doing it again, I'd seriously look at car roof mounts.
Wife didn't want that as we'd need to carry steps or a small ladder due to the height, but I have to use a small stepladder to get our bikes on and off the Thule rack anyway.  So no benefit.
 

[xtrailman]

13 hours ago, David McIntyre said:

If I was doing it again, I'd seriously look at car roof mounts.
Wife didn't want that as we'd need to carry steps or a small ladder due to the height, but I have to use a small stepladder to get our bikes on and off the Thule rack anyway.  So no benefit.
 

 

I'm only 5 foot 5 and remove the bikes standing on the door stool.

[Atthelocal]

Thanks everyone for your comments.