Hello Torsten,
Alejandro, Aitor, Cesar and me all agreed to never have seen any tighter loops coming with the closest to straight fly-leg in addition as those I shaped with Alejandro's very heavy (almost zero bending) 9 feet graphite "broomstick". Aitor made a slomo proof for those my loops. Let me add, that this was me casting a broomstick for a first time ever. There was room for improvement (not in terms of a smaller loop though), if only I would have trained with that stick.
"Ok loops" doesn't reflect what's possible ime.
Efficiency needs to be adressed in my point of view. Efficient in what exactly?
Tobias started his investigation, because he had a missunderstanding, when reading some postings here on SL. He thought, some SL users were saying, that rod flexibility castingwise only has disadvantages and wasn't needed. But to my best knowledge no one ever said that.
Based on this Tobias wanted to proof this statement to be wrong. For that he set parameters like this:
- zero mass for the broomstick and (flexible) fly rod
- same (100 degree) arc for both tools
- zero rod hand path for both (rotation only)
- tip path post RSP1 fly rod was left out
- the decelerational fraction of the arc for the broomstick was left out, too
- angular velocity was put the same for both rods
- the fly line to be accelerated was put constantly straight
- tip path for the flexible rod RSP0 to RSP1 was put straight
The efficiency he calculated was not representing any fly cast, but only reflecting on the energy transfer fly rod/broomstick to fly line.
A fly cast is about putting my fly to the target, usually a fish. If I fail to hit the target, I most likely will have to repeat the cast. Thus I spend twice the energy to hit the target. In other words: If my cast isn't effective at all, then efficiency seen for the purpose of my cast goes down the drain. In fact it's not worth comparing it at all.
In my opinion there is a very little sense in calculating efficiency for the cast without including loop shape, line speed and direction until the fly hits the target. It's great to compare line speed, but line velocity is what counts much more as you know better than me. When casting against wind, I would choose the tight loop and straightest possible fly-leg in low speed over the medium loop with a more convex fly-leg in high speed. This is based on my real fishing life experience.
Back to Tobias his investigation. No one I know would cast a broomstick with a straight as possible rod hand path (or even worse: rotation only) and a relatively wide arc. Instead one would add a rod hand lift at both sides of the stroke and keep the arc as small as possible. This would make for a much better fly cast - more effective and more efficient, too.
If a broomstick would not have any mass, I would take it castingwise (of course only castingwise) in some situations. No doubt we would see brilliant loops going pretty far. It would be a strong weapon in heavy winds.
Compared to that the flexible rod will open the loop front more and the cast imo will automatically loose efficency and often be less effective in fighting wind due to that.
Reality however is, that we have ZERO use for a none flexible stick, because it has too much mass, because it asks for a high level of force application within a small arc, because it asks for a tricky rod hand path, because we need some arc for deceleration, because we need high force to decelerate it and so on.
Taking the way Tobias made his calculations, a pretty flexible rod would be more efficient as a pretty stiff one as he concludes. That is because tip path would be closer to straight with the more flexible rod (if not Tobias would have set a straight path RSP0 to RSP1 for casting his RPL+ anyway instead of using a realistic tip path).
The truth however we see in the WC (stiffer rods in distance). The reality is, that it all depends on the many key factors being relevant in every single situation (tackle set up, type of cast, outside conditions and the abilty of the caster to list a few).
Here is what Tobias said, when having been questioned about his choice of tip path for the broomstick:
"There is no single clue, that the broomstick could be cast more efficient when applying different movements to it."
Well, this is wrong and was already been proven many times by slow motion studies.
If I would want to prove Tobias his findings to be wrong, I could set parameters like this:
- huge force applied for both tools
- tip path for a very flexible rod drops too much and a tailing kills the unrolling
- rod hand path adjusted for the broomstick to achieve a straight tip path and a very tight loop drives the fly to the target
Would there be a point in this?
Not at all. Fly casting is not about a sterilized model. We only ever will cast in the real world. If a model does not fit, it has failed.
Regards
Bernd
P.s.: No offense against Tobias his effort (which I appreciate a lot) or anyone intended. Just being straight in how it looks to me.