Thinner Lines = higher speed

[Paul Arden]

Hi guys,

Something I really notice when shifting through line weights is how much faster lighter lines move through the air. It’s quite noticeable even between a 4 and 6 weight line - or of course a high floater and an Intermediate.

Apart from the obvious debunking the heavier line for faster loading myth, it matters when taking fast shots.

Can someone neatly explain the whys and wherefore please?

The difference in speed between line densities is because the lines have same mass but different diameters. The lighter weight line travelling faster is not so obvious - although thinner lines obviously have less air drag. Has any studies been done on false casting speeds with different line weights? Is in fact the lighter line travelling faster because we can reach higher speeds in the stoke rather than because the lighter line is thinner? Mass to diameter heavier lines are more efficient (?) or is it because the thinner lines form tighter loops?

Thanks,
Paul
(Ducking for cover)

[James9118]

Paul,

I think we need some (proper) measurements before people start theorising over what is just, at best, a single gut feeling.
Do you think you can generate more speed with a #1 when compared to a #5 or higher?
Do you cast the exact same loop size with the #4 and #6?
Is your launch speed identical with the #4 and #6?
Which do you cast further, a #4 or a #6?

Cheers, James

[Paul Arden]

Hi James, it’s a pretty easy test - false cast 4, 6, 8 and 10WT lines as fast as you can (as if you were drying the fly). The speed differences are very easy to see!

Cheers, Paul

[Paul Arden]

Do you think you can generate more speed with a #1 when compared to a #5 or higher?
- I don’t have a 1WT. Lightest is a 3WT. Every time I drop a line weight false casting a fixed length of line is noticeably quicker.

Do you cast the exact same loop size with the #4 and #6?
- no as I pointed out dropping line weights makes the loop diameter smaller.

Is your launch speed identical with the #4 and #6?
- no I’m pretty sure the lighter I go, the fast the launch speed. Is that less air drag, less line mass or both?

Which do you cast further, a #4 or a #6?
- #6

Do you find the same? For me it’s very noticeable because I regularly switch line weights while fishing. Snakehead are 10 or 8 and Gourami are 6 or 4. I notice the difference when switching fish as well as line classes between fish. One of the first things I do when familiarising myself with a new rod is to false cast and hit imaginary targets (to dial in leader length).

Cheers,
Paul

[Merlin]

Hi Paul

Same casting arc / stroke for all lines?

Merlin

[VGB]

I think we need some (proper) measurements before people start theorising over what is just, at best, a single gut feeling.

I think my line speed is higher at loop formation with a lighter line on the same rod but it might be my gut getting bigger I may be accelerating it earlier because the system is less prone to tailing but it may be that different taper lines at different weights will completely invalidate this theory. Why don’t cowboys take off when they spin a lasso? Maybe I need to go fishing again.

[James9118]

Hi Paul,

Ok before we get too deep into this I think we should think up some experiments.

How about something along the lines of:
Two outfits - one light, one heavier AFFTA rating, both with the same length rod.
Both with identical amounts of line extended from the tip.
Then time how long it takes to do 10, 20 or whatever casting strokes, all with good form - none of that lion taming, whip cracking that you usually do

Would that work? Obvious you have to try to be fast with both outfits

James.

[Paul Arden]

Hi Paul

Same casting arc / stroke for all lines?

Merlin

This I can’t say Merlin, but tight loops with rods that feel to have the same action respective of weight. Obviously it doesn’t work if your 4WT rod feels softer than your 6. And it’s not a fair comparison if all the lines are thrown on the same rod.

I’m looking at the fast false casting cycle. However I find it very obvious so I’m surprised there is any question!

Cheers, Paul

[Paul Arden]

Of course James. That will work very well. I’m away from the boat until later in the week but can film the results then.

Cheers Paul

[Merlin]

I was assuming that it was for different lines on a single rod. Your answer puzzles me

Merlin