Lower hand versus upper hand

[Alejandro]

At the moment, it is usually said that the lower hand is the most important to rotate the rod. It is said that the lower hand works and the upper hand is limited to mark the way of the cast and to act like pivot (of this it is spoken largely in the fulcrum topic).

The defense of the cast with bigger emphasis in the use of the lower hand is usually based in a supposed better use of the lever-rod on the part of that hand.

The advantage of using a rod, and not to cast the line directly with the hands, it is that the rod amplifies the speed of the hands. Hence we can forget, at least in principle, aspects like the force that each hand applies and to center us in its speed. I already know that there is not variation of speed without force, but really for us the speed is the important thing: what we want is that a short movement of the hands becomes a long movement of the tip of the rod.
The enclosed drawing shows what it happens when the rod rotates on the lower hand ("upperhand" cast: only the upper hand moves, and the lower hand acts as only fulcrum); when the rod rotates on the upper hand (“lowerhand" cast: only the lower hand moves, while the upper acts as only fulcrum); and when the two hands move ("twohands" cast: the rod rotates under the action of a couple of forces, the two hands act as fulcrums and the rotation center is among both hands).

The arrows show the distance traveled by the tip of the rod in each case. The short lines show the distance traveled by the mobile hand (or hands) in each case.

Not I know what you will say, but for me there are two clear things: the reason for which no caster only moves a hand; and the reason for which the simultaneous use of the two hands is more effective.

Alejandro

[Bernd]

Hello Alejandro,
nice topic and nice drawing.
I think we all agree:
Using only the top (upper) hand to add force to rotate the rod while using the bottom (lower) hand ONLY as a (static) fulcrum would be very ineffective.

Yet I don't agree that using both hands in a 50/50 ratio would give best results.
I think the answer is in the length of line and the overall speed which is necessary for that length of line.
The longer the line is the more speed is necessary. Therefore we need a wider arc anyway. To me that is when your 50/50 ratio works best.
But on the short line I get great arc control and really abrupt stops with little effort when adding more force via bottom hand.

I have tried both many times. But I always came back to a significant bottom hand style. It always made me feel more comfortable.

Post 276 in the fulcrum thread has more details about this.

Let's try to think the other way round:
We have a given length of line. Therefore we need a proper speed of our rod tip. Arc should be small.
Lets say we will use the same distance of tip travel in all three of your cases!
How about the distance our hands would travel in each case?
And which one would be best?

Greets
Bernd

[sms]

I think for long line and long distance, I use way more than 50% top hand.

For simple, shortish casts with short to medium length light lines I use fairly equally both hands. It is very light.

Comparing to top hand movement, when one moves bottom hand, you essentially shorten the rod, so it is easier to move the rod, but to gain the same tip speed you need to move the hand faster.

The theoretical optimum might not be 50/50, it may be 55 top/45 bottom to balance out the rod "shortening" for minimum hand velocity in reference to the caster's body. I haven't calculated it, but I might do that.

[Magnus]

Thinking through Alejandro's drawing and looking at video led to this. Not meant to be to scale. Cast going right to left

[Paul Arden]

If we take those three types of cast, the casting arc is narrower for the bottom hand pulling that the other two. Same force applied, therefore tighter loop?

Cheers, Paul

[easterncaster]

.....

[Magnus]

If that's Alejandros drawing you're talking about - the distance of tip travel looks the same in all three - so the casting arc is widest (largest angle change) in the bottom hand pulling version.

[Paul Arden]

The tip travel is different in all three. Red/Blue/Pink. Blue is shortest, narrowest CA. The bottom hand in blue moves the same at as the top hand in red.

[Magnus]

Ok - Alejandros drawing - so which stroke produces tails and which open loops?

[Paul Arden]

The fish with the blue tails is the tightest loops. They progressively open from then on. But I agree with your trajectory too.

Cheers, Paul

[Hal Jordan]

Hmmmm - where have I seen that drawing before?

[Thomas_E]

Hello all,

Knut and Trond Syrstad, they teach in their courses, mainly the lower hand to use and look this clip when Knut make a cast in Competition with very long head :

http://www.youtube.com/watch?v=PR9se2KY8s4

:p

Greets
Thomas E.

[Alejandro]

An explanation, in the drawing the casting arc is the same: 20º

Obviously it is a simplification, I only keep in mind the difference of speeds of both hands. The traslation movement is not important in this case, because it doesn't affect the role of the rod like multiplier of speeds of the hands.

Bernd, the speed of the tip can be the same. Not there is any reason so that it should be higher when we use both hands: we should only move the hands more slowly.

[sushiyummy]

From my point of view, the tip travel must be interpreted in the context of the formula, Energy= Accelerating force x Distance travel.

Firstly, the rod section between the top and bottom hand represent a very useable and efficient energy storage. It is most capitalized with the top hand as a pivot.

My second take is more conjecture, but here it is.

My understanding of Underhand rods is it is designed w/ flexible tip, but very stiff lower section. I believe the tip section (and the rest of the rod till the top arm) gets its load during phase 1 of the cast (both hands supporting the rod without one hand pivoting against the other).

I am thinking perhaps phase 2 takes advantage of the stiffer lower butt section, using it as much of a lever as an efficient spring to accelerate the loaded tip (that gets most of it's load in Phase 1) mentioned above.

If you somewhat agree with this so far, the lower butt section- now carrying a loaded tip- has very little opportunity to 'flatten' during phase 2. And as a result of this very little flattening, the arc required to travel to carry this loaded tip section in a imaginary SLP (for the loaded tip) is also small. Almost like casting a stiff fast action rod.

Almost like there are 2 rods majorly loading in different phases. The first is tip to top hand section loading in Phase 1, the second is the section between hands loading and multiplying speed in phase 2.

But then, I just ate Ramen noodles and the MSG is talking.

[sushiyummy]

Check out this Competition distance casting from Matthias representing Zpey rods.

http://youtu.be/ATV7Up-Dqlk

I downloaded this video and slow it down to 1/10th of the original speed. It appears to me Matthias initiates the rod bend with a top hand pivot.

After that, both hands push/pull to maximize tip speed and to get SLP maximized for a loaded tip.

This supports Alejandro's contention both hands come into play during the loading phase.

But keep in mind, most fishing don't often cast these prodigious distances with such behemoth setup.

And then, there is that bent rod design few of us have. I heard that if you really pull hard, that bent section actually straightens out to look like a straight through rod. Still eating wheaties to get to that point.