Furled Leaders are tapered furled threads.

Progressive (Parabolic) Furled Leaders, have each segments reduced at a predetermined percentage from the previous segment, giving the Progressive (Parabolic) Furled Leader, a balance reduction in mass (weight) over the length of the leader, resulting in a balanced transfer of the energy in the casting motion to the fly.

Below is a "How-To" example of a Progressive (Parabolic) Furled Leader Formula that can be used to design any Furled Leader you wish to use.

I start, and end, my Furled Leaders by using full loops. This will give added strength for the building process when twisting and will hide the tie-off knot.

I tie the thread in at the 2nd Peg on each side of the jig, and tie-off (in this demonstration) at the 3rd Peg. The formula will compensate the extra strands of thread in the 1st and 3rd loops.

80 inches Progressive (Parabolic) Furled Leader

Four (4) pegs used for the Left and Right tracks, for the tapered furled leader jig.

Loop sequence: 6 - 4? - 3

Thread count per section
24 - 21 - 18 - 15 - 12

Reduction in mass (weight) per segment is 55%, from previous segment.

All percentages based on the starting segment, which is 100% or 1.000 in the calculation. Before determining the final lengths for each segment.

To compensate for the reduction in number of strands of thread in each segment of the Tapered Furled Leader, a ?Correlation Factor? is used to compensate for the difference in mass/length for the new segment in relation to the previous segment mass/length. The Correlation Factor is number of thread strands in previous segment/number of thread strands in the new segment.

S1 = 1.000

S2 = (1.000)(0.55)(24/21) =
S2 = (1.000)(0.55)(1.143) = 0.629

S3 = (0.629)(0.55)(21/1 =
S3 = (0.629)(0.55)(1.167) = 0.404

S4 = (0.395)(0.55)(18/15) =
S4 = (0.395)(0.55)(1.200) = 0.267

S5 = (0.261)(0.55)(15/12) =
S5 = (0.261)(0.55)(1.250) = 0.165

Total Percentage = 1.000 + 0.629 + 0.404 + 0.267 + 0.165 = 2.465

Total Length/Total Percentage = Length S1/Percentage S1
80 inches/2.465 = Length S1/1.000
Length S1 = (80 inches)(1.000)/2.464 = 32.467 inches (32 inches)

80 inches/2.465 = Length S2/0.629
Length S2 = (80 inches)(0.629)/2.464 = 20.422 inches (20 inches)

80 inches/2.465 = Length S3/0.395
Length S3 = (80 inches)(0.395)/2.464 = 12.825 inches (13 inches)

80 inches/2.465 = Length S4/0.261
Length S4 = (80 inches)(0.261)/2.464 = 8.474 inches (8 inches)

80 inches/2.464 = Length S5/0.179
Length S4 = (80 inches)(0.179)/2.464 = 5.812 inches (6 inches

Jig Peg Placement
(Peg positions are rounded to the nearest 1 inch

L1/R1 = 0 inches
R2 = 32 inches
L2 = 53 inches
R3 = 66 inches
L3 = 75 inches
L4/R4 = 80 inches

This is an adaptation of Dave Ulmer (slicfoots) knotted tapered leader formula that can be found in the archives of FAOL "The Big Leader Formula" in James Castwell's column.

~Parnelli

Postscript: You can change any portion to the formula to suit your needs.

Changing the number of Loop Sequences and/or Loop Intervals.

Change the percent of reduction, for each section.

Change the Total Length of the Line.

If you want to have some added length at the Butt or Tip in you can adjust the peg positions after you have determined the spacing in the formula.


[This message has been edited by Steven H. McGarthwaite (edited 05 January 2006).]