Having used both, I can confirm that the four-wheelers require smoother surfaces and any small obstacle requires some small conscious effort, while two-wheelers are much more forgiving of obstacles.
Interesting, do you happen to know why? Naively I’d have thought the taller wheels would be better at obstacles (less likely to get the case itself caught on something, though this ~never happens with my two wheel so whatever), plus in my head the wheels are bigger which should also help. But I guess they’re also on casters, maybe those are bad at obstacles? Looking at wikipedia I could imagine flutter being a problem. Also the weight is further away from the ground, but my guess is not enough to make the case significantly less stable.
For me, four-wheeler means four wheels like those on an office chair. The suitcase stays vertical and is directed by the pull-out grip. Two-wheeler means two fixed wheels, and you pull the suitcase angled 45° on a somewhat longer pull-out grip like a cart. The wheels can be the same size, but I also had ones where the two fixed wheels were larger (2x?). Larger wheels are more forgiving of obstacles as people who use both roller skates, scooters, and bicycles know. But even if they are the same size, the ability of the four wheels to go into different directions causes them to budge on small obstacles, while the two fixed wheels necessarily follow you along.
Having used both, I can confirm that the four-wheelers require smoother surfaces and any small obstacle requires some small conscious effort, while two-wheelers are much more forgiving of obstacles.
Interesting, do you happen to know why? Naively I’d have thought the taller wheels would be better at obstacles (less likely to get the case itself caught on something, though this ~never happens with my two wheel so whatever), plus in my head the wheels are bigger which should also help. But I guess they’re also on casters, maybe those are bad at obstacles? Looking at wikipedia I could imagine flutter being a problem. Also the weight is further away from the ground, but my guess is not enough to make the case significantly less stable.
For me, four-wheeler means four wheels like those on an office chair. The suitcase stays vertical and is directed by the pull-out grip. Two-wheeler means two fixed wheels, and you pull the suitcase angled 45° on a somewhat longer pull-out grip like a cart. The wheels can be the same size, but I also had ones where the two fixed wheels were larger (2x?). Larger wheels are more forgiving of obstacles as people who use both roller skates, scooters, and bicycles know. But even if they are the same size, the ability of the four wheels to go into different directions causes them to budge on small obstacles, while the two fixed wheels necessarily follow you along.