11-16-2005, 10:21 PM
[font "Poor Richard"][green][size 4]Many of us are not expert casters and are not able to evaluate the best line weight for use with a rod. Al Kyte, longtime fly casting teacher, author, and equipment advisor has used his expertise to evaluate the line weight for use with 22 rods. Rod stiffness for these rods was measured at California Polytechnic State University. The line weight rating vs. rod stiffness data presented in Figure 1 shows a high correlation between rod stiffness and Al Kyte's line weight rating. The line weights recommended by Al Kyte often do not correspond to the line weight rating labeled on the rod, yet the line weights do correlate impressively with overall rod stiffness. The correlation shown in Figure 1 holds true regardless of rod manufacturer, rod length, rod material, or other rod characteristics.[/size][/green][/font]
[font "Poor Richard"][green][size 4] How can you put this information to use with your rod? If you follow the experiment described here, you can determine the stiffness of your rod and find out what size flyline an expert would select for it. Start the experiment by clamping the handle of your fly rod to a tabletop (See Figure 2). The objective is to keep the rod handle rigid when a weight is applied to the rod tip. If bending of the rod handle is observed, you may use a wedge between the handle and the tabletop. Apply a weight to the rod tip top to obtain a vertical rod tip deflection of no more than one tenth of the flexible portion of the rod. The flexible portion of your rod is the rod length exclusive of the rod handle. The floor may be used as a reference for your vertical measurements. Rod stiffness is defined as the tip weight in the units of grams, divided by the tip deflection in inches. In equation form:[/size][/green][/font]
[font "Poor Richard"][size 4][green]Stiffness = Tip Weight(grams)/ Tip Deflection(inches) {For example if 18 grams moved the tip three inches the stiffness is 18/3 = 6 grams per inch,which would mean an eleven weight rod per the graph. You knew this but your editor did not so he is inserting this example} [/green][/size][/font]
[font "Poor Richard"][green][size 4]If you don't have a scale to determine your tip weight, you may want to impose on the chemistry department of your local high school or college. If you use ounce tip weights, one ounce is equivalent to 28.4 grams.[/size][/green][/font]
[font "Poor Richard"][size 4][green]We now provide an example. With your rod handle clamped to a table, the vertical distance from the rod tip to the floor may be 30 inches. Assuming you attach a one ounce weight to the rod tip, the vertical distance from the bent rod tip to the floor may now be only 22.5 inches. The tip deflection was then 7.5 inches and the stiffness of your rod is 28.4grams/7.5inches = 3.79 grams/inch. Now check to see that the deflection (7.5 inches) is less that 10% of the flexible length of the rod. Your experiment was valid if the flexible length of your rod was more than ten times the tip deflection,. or 75 inches (slightly over 6 feet) for this example; if not, repeat the experiment using a smaller tip weight. Now with the use of Figure 1 using stiffness = 3.79 grams/inch, it is recommended that you use a 9 weight line with your rod.[/green][/size][/font]
[font "Poor Richard"][green][size 4]Figure 1 can be used to determine the line weight an expert caster would choose for your rod so that you will be able to properly load your rod with minimum effort. If you have built or repaired a rod, have a rod without a labeled line weight rating, or suspect that the line weight rating labeled on your rod is incorrect, this experiment will allow you to choose a line weight which best matches the performance characteristics of your rod. You may find that your casting ability will improve significantly when you use the line weight with your rod that is recommended by Figure 1.[/size][/green][/font]
[font "Poor Richard"][size 4][green] (In compressing this graph we have lost a lot of detail because we don't yet know how to crop the graphic without compressing it. The horizontal scale is Stiffness(grams per inch) and the vertical scale is (Line Weight Rating [Al Kyte]) Your editor intends to ask the authors about creating a written table to go with this graph. The graph shows more nuances of stiffness and weight than a table would but having both would be nice. The circles show the figures for the various rods tested)[/green][/size][/font]
[font "Poor Richard"][green][size 4]Here is the table, which has been aging in my file, like good wine. Soon there will be a clearer scan of the table and a picture of the device used to develop this data. [/size][/green][/font]
[font "Poor Richard"][green][size 4]Stiffness Range Recommended Line [/size][/green][/font]
[font "Poor Richard"][green][size 4] (grams/inch) Weight[/size][/green][/font]
[font "Poor Richard"][green][size 4]1.4 - 1.6-----------------------------3[/size][/green][/font]
[font "Poor Richard"][green][size 4]1.6 - 1.9-----------------------------4[/size][/green][/font]
[font "Poor Richard"][green][size 4]1.0 - 2.2-----------------------------5[/size][/green][/font]
[font "Poor Richard"][green][size 4]2.2 - 2.6-----------------------------6[/size][/green][/font]
[font "Poor Richard"][green][size 4]2.6 - 3.0-----------------------------7[/size][/green][/font]
[font "Poor Richard"][green][size 4]3.0 - 3.5-----------------------------8[/size][/green][/font]
[font "Poor Richard"][green][size 4]3.5 - 4.15----------------------------9[/size][/green][/font]
[font "Poor Richard"][green][size 4]4.15 - 5.0---------------------------10[/size][/green][/font]
[font "Poor Richard"][green][size 4]5.0 - 5.9-----------------------------11[/size][/green][/font]
[font "Poor Richard"][size 4][green] [/green][/size][/font] [center][font "Poor Richard"][green][size 4][/size][/green][/font] [/center]
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[font "Poor Richard"][green][size 4] How can you put this information to use with your rod? If you follow the experiment described here, you can determine the stiffness of your rod and find out what size flyline an expert would select for it. Start the experiment by clamping the handle of your fly rod to a tabletop (See Figure 2). The objective is to keep the rod handle rigid when a weight is applied to the rod tip. If bending of the rod handle is observed, you may use a wedge between the handle and the tabletop. Apply a weight to the rod tip top to obtain a vertical rod tip deflection of no more than one tenth of the flexible portion of the rod. The flexible portion of your rod is the rod length exclusive of the rod handle. The floor may be used as a reference for your vertical measurements. Rod stiffness is defined as the tip weight in the units of grams, divided by the tip deflection in inches. In equation form:[/size][/green][/font]
[font "Poor Richard"][size 4][green]Stiffness = Tip Weight(grams)/ Tip Deflection(inches) {For example if 18 grams moved the tip three inches the stiffness is 18/3 = 6 grams per inch,which would mean an eleven weight rod per the graph. You knew this but your editor did not so he is inserting this example} [/green][/size][/font]
[font "Poor Richard"][green][size 4]If you don't have a scale to determine your tip weight, you may want to impose on the chemistry department of your local high school or college. If you use ounce tip weights, one ounce is equivalent to 28.4 grams.[/size][/green][/font]
[font "Poor Richard"][size 4][green]We now provide an example. With your rod handle clamped to a table, the vertical distance from the rod tip to the floor may be 30 inches. Assuming you attach a one ounce weight to the rod tip, the vertical distance from the bent rod tip to the floor may now be only 22.5 inches. The tip deflection was then 7.5 inches and the stiffness of your rod is 28.4grams/7.5inches = 3.79 grams/inch. Now check to see that the deflection (7.5 inches) is less that 10% of the flexible length of the rod. Your experiment was valid if the flexible length of your rod was more than ten times the tip deflection,. or 75 inches (slightly over 6 feet) for this example; if not, repeat the experiment using a smaller tip weight. Now with the use of Figure 1 using stiffness = 3.79 grams/inch, it is recommended that you use a 9 weight line with your rod.[/green][/size][/font]
[font "Poor Richard"][green][size 4]Figure 1 can be used to determine the line weight an expert caster would choose for your rod so that you will be able to properly load your rod with minimum effort. If you have built or repaired a rod, have a rod without a labeled line weight rating, or suspect that the line weight rating labeled on your rod is incorrect, this experiment will allow you to choose a line weight which best matches the performance characteristics of your rod. You may find that your casting ability will improve significantly when you use the line weight with your rod that is recommended by Figure 1.[/size][/green][/font]
[font "Poor Richard"][size 4][green] (In compressing this graph we have lost a lot of detail because we don't yet know how to crop the graphic without compressing it. The horizontal scale is Stiffness(grams per inch) and the vertical scale is (Line Weight Rating [Al Kyte]) Your editor intends to ask the authors about creating a written table to go with this graph. The graph shows more nuances of stiffness and weight than a table would but having both would be nice. The circles show the figures for the various rods tested)[/green][/size][/font]
[font "Poor Richard"][green][size 4]Here is the table, which has been aging in my file, like good wine. Soon there will be a clearer scan of the table and a picture of the device used to develop this data. [/size][/green][/font]
[font "Poor Richard"][green][size 4]Stiffness Range Recommended Line [/size][/green][/font]
[font "Poor Richard"][green][size 4] (grams/inch) Weight[/size][/green][/font]
[font "Poor Richard"][green][size 4]1.4 - 1.6-----------------------------3[/size][/green][/font]
[font "Poor Richard"][green][size 4]1.6 - 1.9-----------------------------4[/size][/green][/font]
[font "Poor Richard"][green][size 4]1.0 - 2.2-----------------------------5[/size][/green][/font]
[font "Poor Richard"][green][size 4]2.2 - 2.6-----------------------------6[/size][/green][/font]
[font "Poor Richard"][green][size 4]2.6 - 3.0-----------------------------7[/size][/green][/font]
[font "Poor Richard"][green][size 4]3.0 - 3.5-----------------------------8[/size][/green][/font]
[font "Poor Richard"][green][size 4]3.5 - 4.15----------------------------9[/size][/green][/font]
[font "Poor Richard"][green][size 4]4.15 - 5.0---------------------------10[/size][/green][/font]
[font "Poor Richard"][green][size 4]5.0 - 5.9-----------------------------11[/size][/green][/font]
[font "Poor Richard"][size 4][green] [/green][/size][/font] [center][font "Poor Richard"][green][size 4][/size][/green][/font] [/center]
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