Why are fly lines tapered?

Have you ever wondered why there is a need for a taper in our lines? There are two properties of a line that concern us: its weight and its elasticity. Both these properties are controlled by the materials in the line and dealing with them together is complicated so a scientist treats them as separate items. Rather than thinking of the line as a slowly decreasing weight with a stretchy core the scientist separates the two and considers the line as a series of decreasing weights joined by a spring.


Now it is easy if you play snooker and bowls. With no spin when the cue ball strikes a colour the cue ball stops and the colour continues at the same speed. However, when the moving ball is heavier as when a bowl hits the jack then two things happen:

1. The bowl continues to move forward after the impact and
2. The jack moves off at a higher speed.


So as a tapered fly line turns over the main body of the line continues to move forward and the lighter tip is accelerated. Simple isn’t it!!