Which factor is critical when determining the load capacity of an elevator?

Determining the load capacity of an elevator primarily relies on the specifications of the pulleys and cables, as these components are crucial for supporting and managing the weight that the system can safely carry. The pulleys and cables must be designed to withstand the tensile forces generated when the elevator is in operation, especially during starting, stopping, and any potential load surges. Proper sizing and material choice of these components ensure they can handle not just the weight of the elevator cab itself, but also the maximum load the elevator is intended to lift.

In contrast, while the speed of the elevator can influence certain operational factors, it does not directly determine how much weight the system can support. The floor count of the building may relate to the overall elevator system design but does not dictate load capacity directly. Similarly, the design of the cab can affect the aesthetics and comfort of the ride but does not inherently impact the load capacity, which is fundamentally tied to the strength and reliability of the pulleys and cables that are integral to the elevator's lifting mechanism.