SLP / Counterflex / Loop size

From Ally Gowans (Including a powerpoint attachment from Grunde Lovoll, PhD). :-

I must be going mad, here are relevant positions drawn from the 500fps video by Grunde Løvoll and put into a PP file just so that we have a reasonably accurate picture of what’s going on. Most of us relax immediately after the stop to cushion rod vibration and this relaxed position tends to be around the max counter-flex and to that extent the counter-flex dictates the loop size which is effectively the separation between the fly leg and the rod leg. You can see this happen here. But of course the line/loop size and shape can be altered during the line’s flight by manipulation of the rod. If you cast with a relatively stiff object such as a cane, walking stick or the like there is very little counter-flex of course and you will get very tight loops indeed, especially of the object is short!

The topic apparently arose during the narrow/wide loop exercises during tests. I expect instructors to explain three types of loops. Crossing loops where the fly leg crosses the rod leg – concave or tailing if you like but they don’t have to be in a vertical plane they can be made in any plane and indeed with either overhead or roll casts. Parallel loops made by an “SLP” where broadly speaking the rod leg and the fly legs are (ignoring the effect of gravity) apparently parallel because again these may be made in any plane. These can also be made at various loop widths but for the tests they must be made as specified. Open loops where the fly leg is widely separated from the rod leg due to a convex path.

Best wishes,

Ally Gowans

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Ally...

HAPPY EASTER !

You are NOT mad or delusional.

As with the three blind men describing the elephant.... any three of us may see different things in even a simple diagram. The diagram is static to describe a dynamic event.

That counterflex can increase the size of the loop is true. Much more so, however, if RSP, whence the loop begins to form, is below (or beyond with different casting planes ) the path previously taken by the rod tip during the earlier part of the stroke.

The point of RSP relative to the earlier path of the rod tip I see as the main thing leading to the size of that loop to which the amount of counterflex can add. This position change of the rod tip is by virtue of a change from SLP to some degree of convexity of the rod tip path up to RSP. Of course the convex path is continued and exaggerated by counterflex after the start of loop formation which is how counterflex can add to the size of the loop..... particularly when casting very flexible rods.

Some of that addition by counterflex is usually diminished by the momentum of the loop as well as rebound. (A dip in the rod leg which is pulled straighter as the flight of the loop continues.)

Once counterflex and rebound are complete and the loop is on its way, we can distort it by manipulation of the rod or with extreme movements even destroy it. Short of destruction, however, we can't really change its size.

I have rigged a broomstick with handle, guides and a tip top. It is rigid .... can't percieve any bend. with this device, I can make tight or wide loops. I do that by stopping and unloading at chosen distances relative to the path of the oncoming line. This yields a convex rod tip path just before loop formation for a wide loop, and hardly any convexity for the tight loop.

THERE IS NO COUNTERFLEX OR REBOUND with that, "rod".

..... So the discussion boils down to which is more important to the formation of a wide loop ? Convexity of the rod tip path prior to RSP ? or convexity of the rod tip path after RSP, during counterflex. ? My view is that it is the former.

At CCI level testing, I do as you stated. At an MCCI level, I expect a much higher level of discussion.

(In our messages, we have not considered the effect of followthrough. I thought we'd address that subject as a separate issue at a later time.)

Gordy