Analysis. How this can be is analysis. Analysis is the process of saying, "this is made of that." It's something we humans do: we break things down into smaller parts in order to reassemble them. Or, in other words, we examine a larger bit of the world to identify smaller bits of the world that compose it, in the expectation that understanding the smaller bits will lead to a thorough understanding of the larger bit. And we take all these bits as if they were things in themselves.
The Buddha teaches that everything is not so much itself as it is made of everything else (interconnectedness). The motorcycle is not a thing separate from all the parts that compose it: they are none other than it. Yet we delight in treating the combined parts as if it were a thing separate from any of them: in assembling the parts, we give them one more bit in the world than previously was, we give them a name. And there are a lot of these (extra) bits whose existence is only by virtue of us naming them. (That is not to deny their existence, but affirm it.) But I digress.
Earth, air, water, and fire are not elements in the sense of assembly, so much as they are ways of seeing bits the world. To simplify, earth is solid. When bits come together to form a greater unit, there is purpose--the assembled motorcycle is greater than all its bits scattered about the floor. Operating together, the bits are stronger by virtue of a function and a purpose. Water is fluid, i.e. movement of bits, relative to itself and others. Each part of the motorcycle operates together, but each is doing its own thing, and in doing its own thing it is contributing to something greater (in the sense that "We are all One"). Wind is motivational force that brings bits together or pushes them around. Every bit acts relative to every other bit to affect their joint function and purpose: the handlebar relative to the wheel affects steering, and to the engine affects power, which affects speed--but also, relative to the driver who manipulates the bike, the handlebar affects where he wants to go. And fire is energy, the warm hum of each bit acting in accord with the others to affect the common functionality.
The elements are way of seeing things as connected, in an exercise of learning to see interconnectedness.
If you haven't already, you may enjoy reading "Zen and the Art of Motorcycle Maintenance."