. . . . .
These couriers – mostly migrant workers from other parts of China – not only need strong legs but also acrobatic skills to balance these massive loads on their tricycles & bicycles while on the move. Where is the center of gravity is in each case?
. . . . .

The thing that is missing in EGGS — and on only TWO wheels instead of three.
While in Korea, I saw that a lot. (These photos are from China.)