Pulley Systems - Flaschenzug This document shows you how to make an effective and useful pulley system. If you study the pictures, you will be able to understand how the ratio of a pulley system is calculated. Understand that the maximum load to the break in a pulley system should not be underestimated. And last but not least I visualized you some systems with different ratios. This is for example useful if you plan to setup longer slacklines.