Pulleys are an integral part of a belt driven systems. They work in conjunction with the belts to generate power and torque. Regardless of what the ultimate purpose is for purchasing new pulleys, increasing the aesthetic appearance, improving performance, or simply replacing a broken pulley, it is important to understand that pulleys are an immensely critical part of the overall drive system, and there are some important factors that will dictate which pulley will be right for your particular project.
One of the first things that should be understood is that the more components that are added to the drive mechanism to be powered, the more precise the pulley ratio has to be in order to ensure that it works effectively and efficiently. If you choose to mix and match pulleys that are not designated for what you are attempting to use them for, you should be aware that major problems could arise. In the instance in which you choose to use more complex components, it will be necessary to develop a clear understanding of the concept of ratios.