Towball mounted storage

[Robina]

We are thinking about a bak-rak base fitted to the tow ball plus a storage box to free up space inside the vehicle.
(The URL keeps doing funny things so please just search for bak-rak)
We would not put valuable things in it just stuff awkward to store in our 6m van - chairs, mat etc.

Does anyone have any experience of their system or have any suggestions for alternative solutions? I would be especially interested in different sized boxes to attach to the base. The Fiamma prices are all a bit eye watering! And they also seem very heavy for something that adds weight to the rear axle.

Thanks for any thoughts!

 

[Robina]

.....answering my own question....

Trying more extensive searching on here turned up several similar questions With answers. Having already got the tow bar the bak-rak base and aluminium box seem the best solution. The plastic one on offer does not seem wide enough for chairs.

Other thoughts still welcome.

 

[r4dent]

Using a bak rak will
Increase rear axle load / Decrease front axle load (causes light steering and, for FWD, wheel spin especially on grass or wet roads) / decrease payload.
You'll also need to address the issues of lights / number plate and(abroad) marker boards

To calculate the loads impact use these formulae just put you own values in
Extra rear axle load = [Weight of rack & Load * (Wheelbase +Overhang + {Projection of box from ear pf van /2 }) ] / wheel base
Reduced front axle load = Extra rear axle load - weight of rack and load
Reduction in payload = weight of rack and load


Here are the calculations for a typical 7.5m van
Values used:- Rack + Load = 100kg: Wheel base = 5m: Overhang (Back of van to centre of rear wheel) = 2m ; Projection =0.8m

Extra rear axle load = [Weight of rack & Load 100kg * (Wheelbase 5m+Overhang 2m + {Projection of box from ear pf van 0.8m /2 } )] / wheel base 5m
= [100kg * (5m +2m + {0.8m /2 } ] / 5m = [100kg * (7m + 0.4m ] / 5m = 740 / 5 = 148 kg

Reduced front axle load = extra rear axle load 148kg - weight of rack and load 100k = 48kg

Reduction in payload = weight of rack and load = 100kg

IMHO you'd be better off with a small trailer. Cost about the same / larger capacity in both volume and weight / less impact on payload and axle loads

 

[mistericeman]

Some useful and not expensive box type stuff on here.... More truck biased (but without the fiamma bling Premium price tag)

Plastic Toolboxes with Europlex locks

 

[Obanboy666]

Just removed a bakrak and Solent box from my now sold pvc.
Worked a treat for me, I used it to store internal / external screen covers, ehu cable, hose and fittings and a couple of folding chairs.

This is the box I used - Lockable Plastic Storage Boxes | Heavy Duty | Solent Plastics
CAPACITY 195 Litres
LOAD CAPACITY 75 kg
WEIGHT 12 Kg
DIMENSIONS (EXT) L 1000 x W 500 x H 480 mm
DIMENSIONS (INT) L 920 x W 380 x H 390 mm
COLOUR Black

Photo’s of my now sold pvc with Rak and box.
Didn’t bother with a light / number plate board as lights on van not obscured box.

May well sell both as won’t be fitting it to my new c class.

 

[Robina]

Just removed a bakrak and Solent box from my now sold pvc.
Worked a treat for me, I used it to store internal / external screen covers, ehu cable, hose and fittings and a couple of folding chairs.

This is the box I used - Lockable Plastic Storage Boxes | Heavy Duty | Solent Plastics
CAPACITY 195 Litres
LOAD CAPACITY 75 kg
WEIGHT 12 Kg
DIMENSIONS (EXT) L 1000 x W 500 x H 480 mm
DIMENSIONS (INT) L 920 x W 380 x H 390 mm
COLOUR Black

Photo’s of my now sold pvc with Rak and box.View attachment 71279
Didn’t bother with a light / number plate board as lights on van not obscured box.

May well sell both as won’t be fitting it to my new c class.

Thanks. Seems to cost £157.00 - seems very expensive for a plastic box.

 

[Robina]

Using a bak rak will
Increase rear axle load / Decrease front axle load (causes light steering and, for FWD, wheel spin especially on grass or wet roads) / decrease payload.
You'll also need to address the issues of lights / number plate and(abroad) marker boards

To calculate the loads impact use these formulae just put you own values in
Extra rear axle load = [Weight of rack & Load * (Wheelbase +Overhang + {Projection of box from ear pf van /2 }) ] / wheel base
Reduced front axle load = Extra rear axle load - weight of rack and load
Reduction in payload = weight of rack and load


Here are the calculations for a typical 7.5m van
Values used:- Rack + Load = 100kg: Wheel base = 5m: Overhang (Back of van to centre of rear wheel) = 2m ; Projection =0.8m

Extra rear axle load = [Weight of rack & Load 100kg * (Wheelbase 5m+Overhang 2m + {Projection of box from ear pf van 0.8m /2 } )] / wheel base 5m
= [100kg * (5m +2m + {0.8m /2 } ] / 5m = [100kg * (7m + 0.4m ] / 5m = 740 / 5 = 148 kg

Reduced front axle load = extra rear axle load 148kg - weight of rack and load 100k = 48kg

Reduction in payload = weight of rack and load = 100kg

IMHO you'd be better off with a small trailer. Cost about the same / larger capacity in both volume and weight / less impact on payload and axle loads

Hmmm - need to do the sums but I don't think we want to get a trailer. Thanks for the formulae though.

 

[Obanboy666]

Thanks. Seems to cost £157.00 - seems very expensive for a plastic box.

I must have shown the wrong one as I paid around£128.00. Expensive yes but great quality and I got a refund of £60.00 as it had a slight leak through the handle.
They offered a full exchange but as I had already ordered a made to measure cover before the leak issue arose I accepted a £60.00 refund so a win situation for me imho.
Make me an offer for the bakrak alone or both if interested, collection only from Teesside.

 

[Robina]

I must have shown the wrong one as I paid around£128.00. Expensive yes but great quality and I got a refund of £60.00 as it had a slight leak through the handle.
They offered a full exchange but as I had already ordered a made to measure cover before the leak issue arose I accepted a £60.00 refund so a win situation for me imho.
Make me an offer for the bakrak alone or both if interested, collection only from Teesside.

OK - thanks. Had not realised you still had them for sale. We are interested and live not far away in York. I'll pm you.

 

[wildebus]

I have a 6' X 4' (internal load space)Trailer and a towbar mounted carrier ( I have the Thule Easybase).

As far as I am concerned they are VERY different solutions. The typical towbar has a maximum hitch load around the 80-100Kg range, so any carrier, box AND it's load must come in under that weight.
If you can manage that, then a trailer is overkill.
If you cannot, then you need a trailer. Simple as that.

Does a load carrier reduce the payload more than a trailer? No of course it doesn't. A trailer can have the same load on the hitch as a loaded carrier so it is the same. It may change the dynamics of the drive a little, but a trailer will have a much greater effect, plus will reduce your legally allowed speeds and access motorway 3rd/outer lanes.

What a trailer WILL do is allow you to shift stuff out your motorhome you would maybe rather not carry to make easier living space on a journey. That can be a benefit.

As I said, I have a Trailer (with around 400kg payload) and I use that when I need to carry bulky stuff and didn't want to take up room inside, but it is my last resort compared to either all internal loads or towbar carrier.

PS. You can get very large and robust storage boxes from places like Costco and B&M for very good prices. I bought one from B&M and secured it to my modified Thule Easybase.

 

[r4dent]

Does a load carrier reduce the payload more than a trailer? No of course it doesn't.

Beg to differ, but a load carrier reduces the payload/ increases the rear axle load and decreases the front axle load by far, far more than a trailer carrying the same load.


A carrier and box with a load of 100kg will decrease payload by 110kg (110 load 10 carrier& box).

A trailer with a load of 100kg will decrease payload by about 10kg (a realistic nose weight fo a "camping trailer".

The turning moment of the trailer is applied at the tow ball and is out (2.1m * 10 kg =21 Kgm), whereas on a carrier it is half way down the carrier (2.5m *110kg = 275kgm).
This means impact on the axle load is over 10 times that of a trailer.

If the trailer has a load of 500kg the nose weight will be 50kg, so the payload reduction is still less than the carrier with a quarter the load.

It is all in the math.

 

[wildebus]

Beg to differ, but a load carrier reduces the payload/ increases the rear axle load and decreases the front axle load by far, far more than a trailer carrying the same load.


A carrier and box with a load of 100kg will decrease payload by 110kg (110 load 10 carrier& box).

A trailer with a load of 100kg will decrease payload by about 10kg (a realistic nose weight fo a "camping trailer".

The turning moment of the trailer is applied at the tow ball and is out (2.1m * 10 kg =21 Kgm), whereas on a carrier it is half way down the carrier (2.5m *110kg = 275kgm).
This means impact on the axle load is over 10 times that of a trailer.

If the trailer has a load of 500kg the nose weight will be 50kg, so the payload reduction is still less than the carrier with a quarter the load.

It is all in the math.

I will disagree with that. Yes it will CHANGE the loads on the axles, but not the overall.
"A trailer with a load of 100kg will decrease payload by about 10kg" - what about the weight of the trailer itself? that is part of the "load" just like the carrier and storage box are part of the load.
"10kg nose weight" - That is much too low for a start. There is no way you would setup a trailer carrying 100Kg to just have 10kg load on the hitch. That would not be a good idea!

Anyway, very different options and the idea of getting a trailer to carry a load of under 100Kg, and one that would physically fit on a carrier fitted to a vehicle that is designed to deal with a towbar with a hitch load of say 100Kg (in which case you would NOT carry a 110kg load as per your example - the carrier IS part of the load), makes very little sense given the dynamic & driving downsides of using a trailer - IMO.
you have a different opinion, and that is fine.

 

[mark61]

Surely the trailer would form part of the GTW, but not GVW.

 

[RV2MAX]

The Load in this instance is part of the GVM , whereas the load of a trailer is part of the train weight , the only alteration a trailer makes to the GVM is the downforce imparted by the hitch .

 

[r4dent]

I will disagree with that.

Do you have a Mathematical or mechanical basis for disagreeing, or is it just gut feeling ?

Yes it will CHANGE the loads on the axles, but not the overall.

Wrong! The majority of the trailer and load weight is on the trailer tyres, only the nose weight is part of the MoHOs payload.

"A trailer with a load of 100kg will decrease payload by about 10kg" - what about the weight of the trailer itself? that is part of the "load" just like the carrier and storage box are part of the load.

Yes but the majority of the weight of trailer and load is on the trailer tyres.

""10kg nose weight" - That is much too low for a start. There is no way you would setup a trailer carrying 100Kg to just have 10kg load on the hitch. That would not be a good idea!

Industry recommendation is nosewheel on light trailes is 7% of trailer + load weight.

" Anyway, very different options and the idea of getting a trailer to carry a load of under 100Kg, and one that would physically fit on a carrier fitted to a vehicle that is designed to deal with a towbar with a hitch load of say 100Kg (in which case you would NOT carry a 110kg load as per your example - the carrier IS part of the load), .

Bak Rak have carriers with a load capacity over 100kg. For once we agree using a carrier & load greater that the max tow ball load is not a good idea.

" makes very little sense given the dynamic & driving downsides of using a trailer - IMO.

with over 40 years towing experience IMO a properly set up trailer have very little impact on driving dynamics. A badly set up trailer can have a disastrous effect on stability but so can a badly set up carrier.

"you have a different opinion, and that is fine.

My worry is that people will make bad decisions based on your erroneous opinion.
I have an opinion based firmly on mechanics and the calculation of turning moment.

 

[wildebus]

I will stick with my opinion that if an externally carried load is small and light enough to go on a towbar mounted carrier, it is overall preferable to having that same load put into a trailer to be towed behind.

Disadvantages of Trailers:
Reduced Speed Limits on all roads compared to a Motorhome under 3.05t ULW
Significantly reduced parking opportunities when stopped
Reduced manouevarbility when driving
Reduced opportunities for Wild Camping

Advantages of Trailers:
Ability to shift loads out of a vehicle over to a trailer to free space

 

[shaunr68]

I had a large plastic box on a Bak Rak on a previous MH and it was perfect for wheel ramps, aluminium chairs, bucket, mop, windbreaks, recycling. Nowhere near or even approaching 100KG but stuff that is quite bulky, sometimes dirty and belongs outside the van. IMHO a trailer would be overkill for such items.

 

[Robina]

I had a large plastic box on a Bak Rak on a previous MH and it was perfect for wheel ramps, aluminium chairs, bucket, mop, windbreaks, recycling. Nowhere near or even approaching 100KG but stuff that is quite bulky, sometimes dirty and belongs outside the van. IMHO a trailer would be overkill for such items.

That is exactly what I want it for and I agree about the trailer. I'm getting slightly worried that I already have a bike rack on the back with two 16kg bikes though. The bakrak and box would fit beneath it.

Did you have a locking box?

 

[shaunr68]

That is exactly what I want it for and I agree about the trailer. I'm getting slightly worried that I already have a bike rack on the back with two 16kg bikes though. The bakrak and box would fit beneath it.

Did you have a locking box?

Hi, the one I had didn't lock. I didn't keep anything of value in it, if someone is desperate enough to nick a pair of muddy levelling ramps they are welcome to them

But I'm sure you could find a way to affix a padlock to one even if not designed to be locked.

 

[mark61]

If within nose weight, towbar mounted carrier seems sensible route. Having same questions myself, trouble is I use rear door, rear racks that swing out are silly money. If I go the trailer route, then I may as well get a proper one, fit a few 100 litre tanks in it for water, diesel and wine, room for a quad too, it never ends :lol-049: