Spreaders are used to separate your lure from your weight when trolling or casting. Unlike cheap, imported spreaders, I craft each one with 3-100# crane swivels and 2 heavy-duty Duo-Lock snaps. I have found that the 90º spring some manufacturers use is unnecessary as the spreader must be straightened after fighting a fish, whether the spring is there or not. Plus, a spreader without the spring creates less drag and turbulence in the water.
Why Should You Use a Spreader?
Lends directional weight and stability to keep the weight
and lure separate when using a dropper weight.
Preparing to cast:
A spreader keeps the lure separate from the weight.
Through the air.
The spreader prevents the leader and lure from wrapping the mainline as the weight is pulling them through the air.
Entering the water:
The increased resistance will make the leader and lure wrap the mainline if you do not use a spreader. Once the weight hits the bottom, the spreader keeps the lure separate from the mainline.