Folding Wheel Luggage

Putting wheels on luggage is such an obviously useful idea that it's utterly surprising we took so long to do it. I remember the evolution of such suitcases as I was growing up. First there were non-wheeled suitcases, sort of zip-up versions of old steamer trunks. Then, those gained wheels in one corner and a strap on the opposite corner - these didn't work perfectly, they were too unstable and the lack of a long handle meant you had to either be the perfect height, or stoop slightly. Nowadays, the design has crystalized around 2 or 4 wheels set as far apart as possible and a longish telescopic handle.

Modern wheeled luggage performs very well in it's natural environment: the glass-smooth floors of airports etc. However, the small wheels and minimal ground clearance are a real problem when encountering even very slightly rough ground. Recently on a trip to Italy, I found that some old cobblestone surfaces and some sidewalk/pavement surfaces made of a sort of compressed grit combined to wear a hole through the tough nylon on the bottom corner of the luggage between the wheels. This is because low ground clearance would cause the case to bottom out and allow abrasion to do what it does.

The solution, should be that the wheels be mounted on pivoted or sliding extensions. When folded away, the wheels protrude the normal amount and you can wheel around the airport just fine. But, seeing an uneven surface, you can pop the wheels out 2-3cm and the bottom of your case will not suffer an abrasive death. This would also be useful if wheeling the luggage across a wet/puddle strewn surface.