As we’ve been providing side panels and the existing wide box, we’ve also been asked for a closable cargo box for a while now. The main goal of this box would be to allow courier and shipping companies to include the Nighthawk as one solution to the last-mile problem. But, more generally, it would allow private and professional users to have a cargo bike with a ‘trunk’ so that the bike could be left alone for a moment without the risk of getting items stolen.
The design criteria of such a box would include:
- the ability to be locked on demand
- a capacity of around 200 litres
- being sturdy and dependable, while trying to avoid being heavy
We spent some time on the choice of a lock that would fit our bill. We were initially thinking of having the top of the box slide onto a lock with a slanted bolt so that closing the box would not require any additional action from the user. This did work but got quickly annoying as one had to unlock the box to open it again explicitly. Another quite similar variant of this lock did provide more flexibility, though the lock would either be in the open or closed position, and the drawer would open and close itself easily provided the lock was open.
Physical properties of the Business Cargo Box
We wanted to maximize the space used on the cargo bed (to provide the needed capacity) while staying light. Thus, we used the same DiBond composite featured in our wide box. Once the box is mounted on the cargo bed, the whole system is even sturdier than we initially thought! In the final design, we achieved a capacity of around 230 litres for the box, for an approximate weight of 11kg.
Weatherproofing of the Business Cargo Box
The physical design of the box tries to avoid rain needlessly leaking into it. Some sealing profile has also been added at the end of the drawer to cover sharp edges and close the gap between the drawer and the box when closed.
The result is a pretty nice looking box! Putting it together and seeing it take its final form was quite satisfying. Some details need some refining, but these are primarily small details: the first iteration is already used to carry stuff around today.