What is ultimate fly line weight for your fly rod? Or what is the ultimate fly rod for your line? The goal is distance.

[Mangrove Cuckoo]

Max power corresponds to both max torque and max rotation speed, and takes place during the acceleration phase of rotation.

Merlin

Merlin,

What about translation during torque and rotation? And of these three inputs, what is the approximate percentage of power from each? Or does that depend upon the physical characteristics of the caster?

[Walter]

Ron

This one’s for you.

https://www.purehockey.com/c/pure-hocke ... flex-guide

[RSalar]

Question 2: This is more than the spring effect; the inertial effect takes places from MCL to RSP.

Merlin

Hi Merlin, It is my understanding that inertia tends to keep an object that is at rest at rest and it keeps an object that is in motion in motion, unless acted upon by an outside force. So inertia, according to my understanding (limited at best), can not make an object gain velocity. The rod tip and line are accelerating after the caster's force is no longer a factor. That sounds to me like like 100% spring effect.

What am I missing in regards to the inertia effect vs spring effect?

--Thanks,

Ron

[RSalar]

Answer: ? I’ll let you bend doesn’t matter guys answer this one

They seek them here, they seek them there but Ron can’t find those Bend doesn’t matter guys anywhere.

Hi Vince,

There are a lot of knowledgeable fly rod people who are in the "bend doesn't matter" camp. In fact the debate has been going on for decades. I know there are those who would like to make this topic into some kind of joke but it is actually a very debatable topic amongst serious people. Don Phillips, in his book, "The Technology of Fly Rods," states on pp. 89, 90: "For decades there has been a significant debate in fly-fishing circles as to whether a fly rod acts as a flexible lever or a spring during casting. There is no question that the angler provides all of the energy required to cast the line, leader, and fly. The issue is whether or not a significant amount of the angler's energy is stored in the flexed rod and then subsequently imparted to the line as the rod unflexes or recoils. Many prominent anglers have expounded on the validity of the spring theory; perhaps an equal number favored the flexible lever. I have always been in the later camp (*bend doesn't matter), because of of my gut feelings about the casting process and because of the influence of people like Peter Schwab and Vince Marinaro who have been quite adamant about the application of the lever theory."

*my words in italics

So although the jokes about bananas, spaghetti, and squirrels are fun and entertaining, no one yet has come up with any practical way to test their theory. Ha ha ha, Ron doesn't get it. We all know he is wrong, ha ha. But some people have actually come up with methods to find out the real answer to the question: Does bend matter, i.e. is there a significant spring effect that helps propel the line farther? Orvis did some work with high speed cameras to find out the truth. Phillips explains what they did and how they did it. It's all in the book -- and it's very revealing.

Cheers,

Ron

[Walter]

Ron,

I’m trying hard to stifle my sobs of sorrow over that one, but what the heck exactly are you looking for?

Something about bend matters. We all got that. But in what context? Maximum distance? Fishing distance? Spring effect? Now it’s spring vs lever?

Merlin has done some great models with a lot of time and effort.

Tobias also has some interesting stuff on the physics side as well.

Many people have done many experiments from totally informal to somewhat formal. None of of them have tried to hide or misrepresent their results. Everyone agrees that bend matters to some degree but not to the degree you seem fixated on. They also said that many other factors are more important. They also made it clear that the degree bend matters changes for each individual cast. But you seem to think from this last post that there is an absolute number. There isn’t. For a bow and arrow cast it’s 100% spring. For a broomstick it’s 100% lever. Your absolute number is somewhere between those two on each an every cast. Kind of like snowflakes- no two are the same. They’ve explained that over the last 40 pages of this thread.

I’ve tried to explore the idea that you are thinking of something else that may be bend related but haven’t quite quantified it in your head yet. But you keep persisting that it’s all about bend. And when shown that, yes bend has an effect but less than you seem to be fixated on, you change the goal sticks.

So again, what the heck are you looking for? Bend matters for what exactly?

Walter

[VGB]

Ron

”Many prominent anglers have expounded on the validity of the spring theory; perhaps an equal number favored the flexible lever. I have always been in the later camp” (*bend doesn't matter) ………
*my words in italics

Do you not realise that a spring and flexible lever are both capable of bending and both can be levers?

Phillips explains what they did and how they did it. It's all in the book -- and it's very revealing.

I’ve read it but please feel free to reveal?

Regards

Vince

[RSalar]

Do you not realise that a spring and flexible lever are both capable of bending and both can be levers?

Of course — but the question is: Does the spring effect result in a significant increase in line speed? Or is all about the lever? I have been postulating from the beginning that the spring effect is significant. In fact I have stated consistently that I believe that there is an optimal bend that creates the maximum spring effect that has a significant effect on line speed. Others have argued against this position.

There are two schools of thought — (I’ve been criticized for being divisive for just stating this fact) — one school says that bend does not matter and the other other says it does. I say that bend matters — in other words, it is my contention that the amount of rod bend during the casting stroke will have an effect on line speed. Others have argued that bend does not matter - a 4 weight rod (actual rating not some number written on it) will cast a 5MED just as far at a 10 weight rod. It really doesn’t matter to me what the truth is — I’d just like to know what it is.

So far there as been no scientific evidence one way or the other. But I look forward to someone presenting something scientific.

— Cheers, Ron

[Walter]

Ron,

Still on the there’s two sides story. Vince and I have both suggested you go back through the thread and see who is in the absolute “bend don’t matter” camp. You say it’s too hard.

You start with absolute farthest distance as your criteria and the studies that you find too hard to go back and read say it’s at most a few feet and applicable only to competition and the data indicates that there is too much variance to pin it down to bend only. Consensus based on testing by the 8 rod, 8 caster study and Paul’s personal study with a group of competition - bend matters but not that much. And since every cast is different there is no specific bend that is going to be optimal for any one caster all the time.

You move on to line carry. Concensus- for you it was bend is everything but for others not so much and every cast is different…

Then it was fishing distances. Same but even less important than competition.

Now it’s spring effect and lever vs spring. Depending on the cast the range of spring is anywhere from 0% to 100% because every cast is different…

You keep getting the same answers but, they aren’t scientific enough for you. Merlin has spent years developing models that he freely shares results from but that’s not science. People are calling you divisive? Not sure if anyone specifically said that because this time I’m going to say I’m too busy to read 40 pages for you and I personally don’t care if someone did or not.

So far the only one I’m hearing say there is a hard BM camp vs a hard BDM camp mentality is you. Everyone else is saying that isn’t that big of a deal. I understand it’s hard to believe that a skilled caster can throw a 5 weight line just as far with a 4 wt rod vs a 9 wt but have you considered that there really isn’t a great deal of difference In the rods you can buy in a shop? No manufacturers sell broomsticks and none of them sell rods that bend double under their own weight. Before the rods make it the shop they get tested a lot. If some characteristic of the rod makes it perform poorly for the average caster then no manufacturer is going to sell that rod. You make your own rods so maybe you get to see the variance first hand?

[Paul Arden]

The only time bend doesn’t matter is when the lever is inflexible.

Cheers, Paul

[RSalar]

Walter,

Just the fact that this discussion in now 40 pages deep should give you an indication that the subject is controversial. If everyone agreed with the bend matters theory it would have ended on page one. There are two “camps” or theories — one is that the spring effect is substantial. Merlin stated that the spring effect can be attributed to as much as 20% of the total energy/line speed. Others have said it matters very little. I just quoted from Don Phillip’s book where he said there are two camps. It’s ok that there are two camps — that’s a good thing. But let’s solve it once and for all.

What do you think would be a good scientific way to determine the effect the bend of the fly rod has on the cast? Instead of debating this forever, let’s come up with a scientific test that we can use to measure the spring effect of a fly rod. Does the spring effect add any line speed? If so how much?

Let’s not get bogged down in personalities and teams and who said this or that. Let’s put some creative energy into figuring out a scientific method to actually measuring the spring effect.

Cheers,

Ron