The Handles:
Without handles it would be pretty hard to move your luggage around so it stands to reason that the handle system should be constructed properly. You should beware of handles that are not secured in place when not in use. If a handle is only held in place by friction, it may potentially pull out during travel making it susceptible to damage. It is important that the handle is not situated on the exterior of the bag. The handle should be well protected. While padding between the handle tubes and the case exterior is desirable, it is not essential.

The Wheels:
Ideally you should look for a wheel system where the wheels and feet are separate units (i.e. not one long unit). This is important because if one wheel becomes damaged, you want to be able to replace just one section as opposed to the whole wheel mechanism. The more embedded the wheel the better. If a wheel protrudes significantly it is usually more susceptible to damage. You should also avoid non ball bearing wheels as they may heat up and damage the plastic around the housing. Many manufacturers now use in-line skate wheels which are strong and durable. The wheels should be inset into the case allowing only a portion of the wheel itself to be exposed. This is a good configuration as the wheel is less likely to be damaged.

The Frames and Casing:
Frames basically refer to the material the casing of the bag is made from. There are generally two types:

1. Hard shell suitcases are molded from materials such as polypropylene, ABS plastics, or metal. Hard-sided suitcases often have in-built security locks. They offer good protection against impact from the outside and are more resistant to water and dust.

2. Soft shell suitcases are partially framed with soft, somewhat expandable tops and bottoms. They are lighter in weight than hard-sided cases but still offer good protection of contents. Like the hard-sided cases these have wheel and handle systems.

Hard or Soft Shell?

Many people ask which is better. What it really comes down to is what you will be using the luggage for and how often you will be using it. For example, if your contents require significant protection or if the bag will be subjected to dusty or wet conditions then a hard shell case may be more suitable.