I need your input in my project

[Oldhippy]

They are not as unwieldy as they look. Like anything else once you get the hang of a cargo bike it becomes normal. You see some monsters in Europe whizzing about and Outspoken cycle delivery company had some big box ones.
Not much different to a fully loaded tourer, if you aren't used to it they look very hard to ride when in actuality not so much.

 

[MichaelW2]

Rear axle hitch is better.
Wheel size should be 16" or 20",(bmx).
With wheels each side that limits side access to doors.
Consider using the top as a work surface, and having a built in stand and hand brake. Trailers pivot and turn on their unbraked wheels.
Tradesmen usually haul their tools around in a box but need space for materials.
What are your limits for width?

 

[The Crofted Crest]

Hate to be critical but every thing about that looks unwieldy and/or dangerous.

Over here in Holland, bikes like that are really common and are used by all sorts of trade people and delivery services (even the post office). They are just a functional variation of bakfietsen.

 

[annedonnelly]

Fritz budgie agreeas with Anne budgie (check the avitars) the trailer needs to lock, it might be nice if it were somehow lockable to the bike and a wheel lock might also be nice. Because I no longer trust anybody.

That's Pippin in my avatar. No longer with us, I'm afraid. He was disabled as a chick but handled a lot by his breeder in an attempt to give him physio. Hence he was a very friendly bird.

Currently there's only Patch here and he's camera shy.

 

[fritz katzenjammer]

That's Pippin in my avatar. No longer with us, I'm afraid. He was disabled as a chick but handled a lot by his breeder in an attempt to give him physio. Hence he was a very friendly bird.

Currently there's only Patch here and he's camera shy.

Thats Pickle in my avatar, he likes attention but just not too close. He can be noisy as hell when we want quiet and then cute and sweet when he wants treats.... typical budgie, I feel so used.

Great pets.

 

[classic33]

You'll be looking at a 3 foot/1m width, and a similar height. Much taller than the width and you create an unstable platform.
You can make it longer, but then you've the rearward view to consider, as well as the turning circle of bike and trailer.

The arm and hitch as shown. Does the arm need to be in two straight pieces, or can you bend it to follow the same route. You're introducing a weak point where it isn't needed.

Wheel size, go for 20" rather than 16". Replacement tyres and inner tubes are easier replace. The larger size will "eat into" the box internal space more, but offer an easier tow.

Is the box also the frame for the trailer, or will it be mounted on a seperate chassis? The latter may be better for overall design. Should it be damaged, only it would require replacement, not the whole trailer. Your anchor points and load bearing parts will be stronger. If you go with the seperate chassis, the lower towing point becomes the more obvious, stronger option.

 

[Tom B]

Needs a roof rack!