The cargo net is a Vietnamese institution: stretch it over almost anything, hook it to the rack, ride away. Bungee cords are its cheaper, more dangerous cousin. The difference between the two — and between using either well — is the difference between a load that arrives and a load that appears suddenly on the road behind you.
Nets vs cords
A cargo net spreads tension over many hooks across a wide area: load clamped, pressure distributed, one system. Bungee cords concentrate force at two hooks; a single cord that unhooks under vibration does so violently, and the load shifts at speed. The rule that follows: nets for almost everything; individual cords only as supplementary cinches, never as the primary attachment. The physics and safety discipline of carrying loads on a motorbike overall lives in carrying-luggage-motorbike-safely-vietnam.
Hook discipline
The four classic failures, all seen daily on Vietnamese streets: hooks to plastic racks (they unhook, or worse, break the rack — hook to metal frame points); hooks stretched straight to their limit (no tension left to absorb bumps — a cord should be stretched within its working range, not at its extreme); hooks through bag straps that tear loose; and the no-hooks-at-all “the net is heavy, it will hold” method. Every hook should have a metal anchor point.
What nets cannot hold
Nets secure shaped, soft, moderate loads. They are wrong for: rigid heavy items (a gas cylinder is not a net cargo, though Vietnam proves daily that it can be attempted — do not), very tall loads (aerodynamics and centre-of-gravity problems — the weight placement rules are in carrying-luggage-motorbike-safely-vietnam), and anything valuable that a net exposes on a parked bike — the lockable option for those items is covered in top-boxes-racks-motorbike-vietnam, and body-carry for the essentials is in what-to-carry-riding-motorbike-vietnam.
Wear and the check habit
Elastic loses memory: stretched-then-relaxed cords, frayed net edges, bent hooks — a net that has lost tension is worse than no net, because it looks secured and is not. Inspect before every use; replace at the first sign of dead elastic. Two nets overlap better than one giant one.
Load low, hook to metal, tension in range, check every ride: four rules that make the humble net the most cost-effective luggage system on Vietnamese roads — with the everyday-bag comparison in backpack-vs-saddlebags-motorbike.