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Discussion Starter #1
I am wondering about the differences in casting distance of a 8/9 rod in three lengths 13, 14, and 15 feet. I would think each added foot in rod length would add a few feet in the cast. My next question is have 3 14 foot rods. A 7/8, 8/9, and a 9/10. The larger line size should add a few feet to the cast. Last spring at the Sandy Clave Juro had 3 rods rigged up with a mid-spey line. I could cast the 7/8 and the 9/10 about the same and the 8/9 was about 10 feet less. Possibility the line on the 8/9 did not match the rod as well. I remember in Jim Vincent's first casting video, he mentioned a rue of thumb. For every foot deeper you wade you would loose about 5 feet in distance. Do you guys think the 5 foot rule of thumb would work in the above examples? Jerry
 

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Not sure about rod length but am not convinced that you necessarily will cast a heavier weight line weight farther.

In single handed casting I can cast an 8 weight as far as I can cast my 10 weight. I think there is a weight limit where added distance is not a given

Maybe in adverse conditions - with wind a heavier line might work better
 

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Jerry,

Longer rods provide you with a mechanical advantage and thus can cast a line farther with the same effort. Heavier lines can also be cast farther than lighter lines with the same length rod.

For example, I can cast my T&T 1510 loaded with an 8/9 GrandSpey a lot farther than I can cast my Loomis GLX 13' 8/9 with an 8/9 MidSpey or 7/8 GrandSpey. The extra 2 feet of rod length and the heavier line certainly are involved in this.

Likewise, I regularly cast and fish my T&T 1611 120 feet in certain runs on the Skagit with the 9/10 GrandSpey and sink tips. Doing the same with a 14 ft 9 or 10 wt would be very difficult to achieve for the hour+ it takes to fish those runs. The extra rod length and line weight are definitely at play here too.

Why do you think most of the top rods at Musto are casting 17' to18' rods? There is no subsitute for the mechanical advantage of rod length, just like there is no subsitute for cubic inches on the drag strip.
 

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Educate my ignorance?

I can't fish at the moment, so I'll nitpick. I'm not sure I buy the idea that a longer rod gives you a mechanical advantage over a shorter rod. I know that a rod is both lever and spring, but from the lever side of the house it seems you'd have less leverage with a long rod. Assuming same weight lines, it seems you'd need to apply more force to cast a longer rod than a short one. That said, with a long rod you'd have more tip travel. I think height off the water is nice too. Can anyone clarify for me?

Carl
 

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I would think that a longer rod could store more energy, hence less energy is needed to physically move the line itself; rather, energy given to the rod by movement would be transferred to the line. In this fashion, I could see a point to be made for longer rods.
On the other hand, I would think that the biggest factor is the graphite used in the blank and the characteristics thereof. Compare blanks of the same length made with different graphites and one is bound to out-cast the other. If that's the case, there should be a sort of inverse relationship between casting distance as it relates to rod length, with graphite and taper characteristics being an equalizer of sorts.
 

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JD
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longer rods

Alexander Grant theorized that for every foot of rod tip off the water, you gained or lost nine feet of casting distance. Example: stand in one foot of water and swing a 13 ft rod, or stand in three feet of water and swing a 15 footer. Given the same line weight, action , conditions, etc, the same distance can be achieved.

Forget the mechanical advantage, or lack of it afforded by the different rod lengths. What matters here is line (tip) speed, stroke length, and height off the water.

The only other thing that comes into play, besides the fact that a line with more mass will keep on going longer (distance) once you get it moving, is physical ability. Some people just can't handle a 16 ft 11 wt rod.
 

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Falkus told me

that by getting the reel up above my ear I would effectively being casting with 16 rather than 15 feet ,It gives a bigger D loop .deep wasing cuts the size of loop you can create .
 

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Discussion Starter #8
Speed, Energy and Mass

I am trying to think of some examples. If you throw a small rock or a larger rock. Then try throwing a rock off a cliff. Now I can visualize how gravity enters the equation. Going a little farther on this thought. A 55 grain bullet from a .22 caliber varment rifle or a 180 grain bullet from an 06. With these thought in mind I can now understand a little more what is happening with the casting loop. I would like to see a few more rules of thumb thrown out there. Jerry
 

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Jerry,

I like the 55 grain vs. 180 grain example. I would take it one step farther and say the ballistic coeficient for that 55 gr. spitzer is much better than for the 180 gr. round nose. When you add velocity into the equation you a whole new dimension.

Have I just made a case for fast actioned rods and short bellied lines?:eek:

'tip
 

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All in good fun

OK, assuming the case I made above is accurate, how come you Skagit liners like those soft actioned noodle rods???:chuckle:

Just joshing you but it does bring up the question of why are the 9140-4 type rods so popular with this casting style. It would seem to me that the fast actioned rods would excel with these line setups in throwing tight bullet shaped loops.
 

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Jolly Buddha
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Soft Rods

I got away from softer rods.
I sold old Brownie to Wetfly.
I've been useing 8124 for years but my shoulder doesn't have it any more.
Thta's why I went to CND Skagit. (Little softer)
 

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Discussion Starter #13
Sink tip, Brians 9140 was gathering dust and I felt sorry for it. I could live pretty high on Brians castoffs. When he gets tired of all those cnd rods I will be waiting. Jerry
 

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Sinktip my friend, if you use a 180 gr spitzer boatail instead of a round nose the advantage goes to the .30 caliber. Same as using a big long-belly instead of a Skagit or Windcutter for spey distance, provided the caster knows how to toss a dynamic D loop with the long-belly.

I also wondered why the Skagit head folks don't use the fast rods like the Loomis 14' 9/10 GLX, T&T 1409, 1309, or 1410, the Loop Green Series 9140, or Meiser's fast recovery rods instead of the slow ones almost all of them use.
 

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what brand/style/#,,?

i have a pile of 14,s,,,all different actions,,and two 15's,two 16's,matched,two 18's,,completely different one's just a fast brute suitable for throwing heads into the next solar system,the other's just a fun forgiving rod that `lays out sweet spey casts all day long'in the `trenches' talking casting distance don't count,fishing does,i'd think you need to try different lines,i know one thing,and i don't know much;once you've found a magic combo,one that makes the casting with that particular rod seem easy;go back and try other lines back to back,try different strokes,a little more power with the lower hand,etc,etc.how you're holding-stroking the rod through the moves,then change back,don't add any major changes to the leader,or bugs being used,set some parameters to help you figure it out,just send me a thousand dollars, your rod,oh,and some flies,i'll send er' back with an extra ,,,,,,how far???,,,certification,,,i really don't like the midspey line,and the windcutter doesn't seem to be my bag either,,,,,,sorry folks,,,,,why not try some loaner lines from redshed,or some of the other fine sponsors here?,after all,they probably get more input than anyone;)
 

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JD
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Nuggets

Jerry
[I would like to see a few more rules of thumb thrown out there.]
Here are some nuggets I've picked up along the way.

Energy=Mass x Velocity squared. Simply put, line speed will do more for you than a heavy line. If you go back to fly casting basics, choose a line that is capable of casting the fly you are going to use, and a rod that will cast the line.

Short cast, short stroke. log casts, long stroke. longer casts, longer stroke. Think of stroke length as the length the rod tip travels.

A longer rod can generate a longer, faster stroke out at the tip.
You can further increase the stroke length by adding drift into the stroke.

A tighter loop is more efficient than an open loop. (boat tail vs. round nose bullet)

These are just simple rules of physics, and as such, they do not change. How you apply these rules, use or abuse them, is technique. And that, my friends, is what separates the men from the boys. :smokin:
 

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The physics of casting is NOT simple. There are all sorts of things posted on the internet about this subject and the vast majority are just plain wrong.

I'll stick my neck out and make a couple general statements regarding rod length and casting.

All other things being equal, a the tip of a longer rod will move at a higher velocity than that of a shorter rod given the same casting stroke. It a simple formula of V = ω L, where V = tangential velocity of the tip, ω = angular velocity of the rod (how fast it is being rotated in the casting stroke) and L would be the effective rod length (which varies as the rod deforms)

Same thing holds true for acceleration: The tip of a longer roid will accelerate at a greater rate than that of a shorter rod (Again, with all other thing being equal) The formula is the same just using linear and angualr accelration terms instead of velocity. a = α L where α = the angular acceleration of the rod (how the rod's speed of rotation, ie the casting stroke, is being increased or decreased ), L the same as above, and a the tangential acceleration of the tip.

There is much much more that goes on but these simple relationships show that a longer rod moves faster and accelerates higher at the tip than a shorter rod. This is essentially what JD said about line speed. By the way JD, you need a leading coefficient of 1/2 in your kinetic energy formula.

Bear in mind the length of the rod changes when it bends. When a rod bends it is storing energy (either the applied force over a distance or the kinetic energy of the moving line or a combination of the two) as elastic energy. This leads to all sorts of other processes that I don't care to go into, but I'll say that the word modulus that gets thrown around so much (usually incorrectly) is more properly termed "elastic modulus" or "modulus of elacticity'. Combine that property with a rods geometry, and the manner and amonut of the loading you can calculate the deflection of the rod and the amount of energy stored in its material.

All this is simplification. Spey casting adds twists (literally!) to this in that there is a torsional component to the loading (tape your furrels anyone?). And then there are the mechanical properties of the lines too. Lines behave in a plastic fashion instead of an elastic manner like the rod.

So, a longer rod will cast further with all other things being equal. As far as line weights go, the heavier line will have more momentum so it will better penetrate wind but it will also have more drag in the air. The effects of drag are real noticable if you ever cast a full sinking line - they will really slice through the air.
 

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:confused: :eyecrazy: :whoa:

Fishing, anyone? I thought this was Spey Basics, not Phys 400. It is interesting, but you'll went over my head on about the 2nd post.

Sure, with a longer rod, all things being equal, will give greater distance, but this is hypothetical as as soon as you lengthen the rod, a lot of other factors change, at least in the real world.

In the real world, a casting skill and having balanced equipment have are a lot bigger equation for distance than simple rod length, for fishing that is. Now if I were heading to Musto (HA!) some of this might be important. Just my two cents. Carry on.
 

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Swinger,
You are of course correct that skill is the biggest factor to good casting (and distance). These things do however apply in the real world and not in some hypothesis -this is why those competitors who have the skills to compete in those competitions use the long sticks. Thge same laws apply to us with much lesser skills.

By the way, My post is more along the lines of a 100 or 200 level engineering mechanics course- no physics 400 for me! ;)

And I agree with your intro inquiring about fishing, If I were not with a bum leg I would be out on the river right now rather than posting formulae and greek letters on this bb.

cheers,
pescaphile
 
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