Shock leader

A shock leader is a length of heavier line between the main line and the rig. It gets confused with a trace, although the job is the opposite: a trace saves you from teeth and snags, a shock leader from your own cast.

What exactly it absorbs

At the moment of the punch the whole weight of the rig hangs on the line, and the shock lands on the thinnest point. The heavier the rig and the sharper the punch, the better the chance it flies off with the lure.

The shock leader puts a thicker length under that load. The main line stays thin — and thin line casts further, which is why it is there in the first place.

Why braid in particular needs one

Monofilament stretches, and absorbs part of the shock by itself. Braided line has no stretch: whatever did not have time to accelerate arrives at the knot undiminished.

So on braid a shock leader is not extra caution but an ordinary part of the tackle wherever heavy things are thrown: a feeder with a heavy cage, a beach cast, a heavy jig.

How much of it to use

Its length is measured in punches rather than metres: a shock leader has to reach round the rig, run through all the guides and lie in several wraps on the spool before the cast begins. Any shorter and it will not take the load in time.

Hence the consequence: the shock leader knot passes through the guides on every cast. That sets it apart from a trace, whose knot normally hangs beyond the guides.

Which is why the knot has to be flat

A knot that hits the guides costs distance and wears the inserts. What suits are joins that lie along the line: the FG and the Albright are described under line-to-line knots.

The clinch, the Palomar and the rest of the eye knots do not work here: they leave a bulky lump, and every cast bangs it against the first guide.

When it is not needed

On monofilament with a light lure — the stretch is enough on its own. At short range, where there is no real punch. And where the rig is lighter than the line: there is nothing to break.

A shock leader and backing are different things

Backing lies underneath the fill and takes up the depth of the spool; a shock leader sits on top, at the end. They are often confused because both are «something other than the main line». On backing, see the entry on spooling.

What we do not state here

How many times thicker than the main line a shock leader should be. The «so many times» rule circulates on forums in several incompatible versions, and we found a verified source for none of them. The working sign is different: the rig has stopped flying off, so the thickness is enough.