Is the trolley suitcase as light as possible?

The trolley case must strike a balance between "strong" and "light"
In the early days, hard-shell suitcases were bulky, especially those made of PP materials. For good protection, the weight of the suitcase body was usually one-third of the weight specified by the airline. (The 29-inch suitcase weighs 8 kg, which is 1/3 of the 23 kg limit)

If you do not consider the flexibility of the material and blindly reduce the weight of the luggage, it will cause the instability of the box. Then the trolley box is just a plastic shell for luggage, which is difficult to protect. A good trolley case must be designed to reduce the weight while considering the stable structure of the case, maintaining the balance of "sturdiness" and "light weight", so that the luggage can perform its functions.

After being pressed by a heavy object, the wheel cannot perform its function and drags unsmoothly.
A structure that is too light or too soft will cause the cabinet to be unstable and easily twisted under heavy pressure.