[drive-through]

Dear listers,
It's winter as y'all well know and I have way too much time on my hands. While reviewing all known to me spey casting videos I was puzzled by the video #24 on the Dana's web site, i.e, "The beautiful longline casting of Mitsuru Kaneko". If one watches closely, it seems obvious that his rod is a pretty slow one since after the power stroke the rod tips keeps going down quite a bit. The puzzling part is that the spey line flies straight out in a beautiful tight loop without a hint of a wave in it. How coud this happen? More importantly, is a there an established repationship between the rod dampening and the cleanliness (spell?) of the cast? Would it be fair to say that after the power stroke one's spey rod does not affect the cast at all?
Thank you.

 

[juro]

Interesting point.

Although there is some post-release deflection (for lack of better term) with any rod, this rod which I believe is a CND Specialist has much less than most and a very high modulus (IM8) so the amount (regardless of rod) is negligible compared to the load coming off the blank that it is propelling the tight loop.

The influence of the deflection can be seen in the shallow angled dimple that rides behind and below the piercing cast loop, and there is some tension between the two as they fly together through the air.

Although pure conjecture, I would argue that this tension between the two is what keeps that loop so tight, and that it would be impossible to keep the same tension constant to the rod tip without it.

Thus my theory is that a uniform, shallow angled shock dimple is an advantage to long line casting. But I am no expert, only a student and certainly don't know for sure. Maybe a guy like Simon Gawesworth or Tim Rajeff could explain better.

But the two things I would offer to this discussion for thought:

1) The counter-action of one directed force against the force of the main forward stroke is not always bad. One could theorize that the tension created keeps things energized along the way.

>> The most obvious example of this is the snap-t cast, where the rod is driven forward against the intial backward lift. The result - the two forces counteract each other and the fly zings past the angler under opposing forces.

2) When teaching single-handed casting, I often use a forward directed snap-t to demonstrate the it's the shock wave that casts the line, not the rod. In other words, pull the rod back sharply at the end of the forward stroke and place the rod down on the picnic table. The deflection-tensioned loop seems to whiplash forward on it's own accord completely detached from the rod.

Good topic!

 

[JDJones]

Shock wave

First let me define what I am referring to as a shock wave. As the rod is brought forward, accelerated under load (bent backwards) and brought to a quick and positive stop, the loop is formed. However, that is not the end of the story. The rod will continue forward, past the perfectly straight position, recoil, or rebound, whatever you want to call it again, and possibly still go past the perfectly straight position another time before all of the energy is consumed by the cast. This is often referred to as damping. Some of the old fiberglass rods were real (whippy) bad at this. The modern graphite rods are much better, having a quicker recovery.

At any rate, this recoil is what causes the shock wave in the line. Now for some reason which I cannot explain, other than having seen it in slow motion digital video, this shock wave will travel down the line at a faster rate and eventually catch up with the main loop (if the line does not come down on the water first). And when it does catch up, it will add it's energy to that of the main loop, thereby accelerating it or kicking it over.