Hi All,
Over the winter I purchased a new William Joseph 3wt rod and a used Orvis Clearwater 3/4 reel. The reel came with a WF3F line that appears to be an Orvis Clearwater line that seems to be in good shape.
I can only cast this new 3wt about 2/3 or 3/4 as far as I can my 5wt that also has an Orvis Clearwater WF5F line.
Is it normal to cast a 3wt that much less than a 5wt?
Harry
The reason is that the 3 wt line has relatively more surface area per mass than the 5 wt line. This is true for all weights of fly line. As fly line weights go up relative surface area to mass goes down. Therefore relative aerodynamic drag (air resistance) goes down as line mass goes up and the higher weight fly line goes farther for the same fly line velocity.
The math is related to simple geometry. If you take the cross section of a fly line it will be a circle. The circumference of the circle represents the fly line surface and the area of the circle represents the fly line mass. If we double the circumference of the the circle, we quadruple the area of the circle. So we can raise the mass by 4 and only get a 2X increase in surface area drag.
This has several practical applications. When casting into the wind, put a higher weight of fly line on the rod. Even though the rod is OVER weighted, you will be able to cast FARTHER. Is seems counterintuitive that a heavier line will go father, but that is because the relative DECREASE in air resistance/mass more than makes up for the heavier line.
Another example is that a sinking line can be cast further than a floating line. They have equal mass BUT the sinking line is thinner so it has less aerodynamic drag so it goes farther. This example is easier to grasp; but the principle at at hand is the same one that allows heavier floating lines to go further than lighter floating line.
