Pull bars (also referred to as "bell cranks") typically are made out of steel or aluminum. They provide a transition from rotational direction to linear direction. In other words, when the cross-shaft and the pull bar rotate, the pull rod (which is attached to the pull bar connected to either the raise finger or the lower finger) moves back and forth. Pull rods can be attached to pull bars with a variety of methods, which may include the use of set screws or just hooking the pull rod onto the pull bar. Modern pull bars usually are either:
- Center-pull, meaning that the pull rod resides in between the 2 sides of the pull bar
- Side-pull, meaning that the pull rod attaches along a single side of the pull bar
The drawing below shows an example of a center-pull Pull Bar, where the pull rod hooks over a pin, which resembles a barbell. The hook prevents the pin from moving sideways. The pin pulls the pull rod when the pedal or knee lever is activated.