Rather than imagine what's true I decided to see what's true. I clamped a 12 foot light surf rod to my workbench at a slight angle above horizontal, suspended a 6 oz sinker from the tip top, then measured and recorded the distance between the center of the rod blank at the tip-top and each of the first five guides to the floor and recorded these distances. Then I tied a length of mono to the rod butt, threaded the mono through every other guide, out the tip-top, and tied the mono to the 6 oz. weight and suspended the weight from the rod. The measurements of the rod blank's center to the floor was the same with or without the guides threaded. Prove it for your yourself. Guide placement does NOT alter the natural arc of the rod under a load.



Edited 1 time(s). Last edit at 06/14/2020 11:05AM by Phil Ewanicki.

Interesting. Did not see that coming.

It does if the guides are not properly placed. You can prove this to yourself by the same experiment but drop a guide or two, and move the spacing a bit.

If this was not true, it would be impossible to create a bow-string effect with poor guide placement.

...........

Phil,
I expect that it would be exactly the same with this amount of weight if you only threaded the line through the first guide and the tip top. (although, with the bow in the rod, the line will be bow string as Mr. Kirkman suggested - so it would likely that more line will be let off the tip due to the bow string effect.

But, if you were to take a piece of cardboard longer than the rod and trace the arc of the rod with the line running through all of the guides, with line running through every other guide, and with the line only running through the first guide and the tip top - and I am expecting that the bent rod arc will be identical for each of the three tests.

Now, if you changed the test so that you had 32 ozs hanging off the rod - or 2 lbs, you might then have a different arc in the rod for the three different tests. i.e. the 2 lbs would load the rod substantially more than it was loaded with 6 ozs.

By the way, if you don't mind - since you have the rod and the line - can you run this test ? i.e. marking the rod arc on a cardboard for each of the three different line routing? Just curious about the results.

Take care

Guide placement can change the way the rod flexes. Take it to the bank.

.............

Roger: I tried tracing on cardboard and got similar but less precise results. It's tough to get and secure a long enough piece of cardboard and to trace over it without bending the rod. I went with a 12' rod to maximize the difference in the bend of the blank and measured to the eighth of an inch. If there is a controlled experiment (versus a "feeling") which contradicts my results I have not heard of it, let alone read about or see it. BTW: If you move all your guides toward the tip-top the rod flex will change - it will slow down, and if you put your guides close enough together they should create a measurable "flat spot" in your rod - but why would anyone do this?

There are controlled experiments and they are easy to accomplish. You will need to load the rod until it has achieved it's full flex (into the lower 3rd of the rod). Do this with just the load attached to the tip. Then add perhaps 3 guides and repeat. Add 3 more and repeat. So on and so forth.

The more guides you add the closer the rod will flex to it's natural intended curve. The less you have, or the more poorly they are spaced, the larger the difference will be between the rod's natural flex and what you'll have with too few or poorly spaced guides.

Set up a camera and keep it at the same angle and distance. Photograph the rod with each different guide set-up. Then compare the photos.

............

Tom: What you suggest is pretty much what I did. I figured for purposes of measuring deflection my bypassing a guide with the line has the same effect as cutting the guide off the blank, and a tape measure is as reliable a measurement as a photograph. Perhaps the rod must be loaded closer to a ninety degree angle before the influence of guide placement changes the curve of the rod? I think I will suspend a bank sinker tied to the tip top of a clamped-down rod and measure precisely where the point of the bank sinker touches the floor; then thread the line through all the guides and secure it when it just touches the floor. If the sinker is NOT right on top of the first mark your claim is proven.



Edited 1 time(s). Last edit at 06/15/2020 12:08PM by Phil Ewanicki.

Tom,
Makes perfect sense.

Tom,
Makes perfect sense.

It seems to me that guide placement has as much or more to do with load distribution than merely the arc of the rod!

Load the rod from the tip, only. Now install a butt guide and a tiptop. Load from there. You will see that compared to the rod loaded from the tip only, where the tip of the blank never exceeds 90 degrees to the butt, the subsequent test with butt guide and tiptop will result in the tip moving back beyond 90 degrees to the butt. Each additional guide will lessen this somewhat. Put enough guides on the rod and the blank's natural flex will be preserved. The idea is to attain this with as few guides as possible.

We've had photos of all this in the magazine some years ago.

.............

Phil: I suspect the taper of the rod has much more to do with total load distribution than the guide placement. The entire rod must bear the total load, no matter where the guides are located or how many guides there are - even if there is only a tip-top connecting the load to the rod. Even if guide placement could alter the bend of the rod [which I doubt] precisely what benefit would that produce? All the strength of a rod blank, any rod blank, ALL BY ITSELF, with any curve, won't cast any line twenty feet.



Edited 1 time(s). Last edit at 06/15/2020 06:51PM by Phil Ewanicki.

Phil, but it will..i made two 50" E=glass rods that toss a 1/4 ounce rattle trap 30 to 35' using a bow and arrow cast..i pull the lure back and release, the rod does the rest..this cast really comes in handy in tight brushy conditions when bank fishing..

Phil, on a fly rod with the guides on the underside when fitting a fish, if you only had a tip top that is where the majority of stress will be, with a number of guides they distribute some of the stress! Case closed!

Used properly, most of the stress falls to the butt - the lower 1/3rd of the rod. This is true with no guides, and is also true with enough properly space guides. The problem is when you have too few guides or guides that are improperly spaced. In that scenario, the load may not properly transfer to the lower 3rd of the rod and over-stress somewhere along the top half. Any time a rod fails from simply being overloaded, it should always break in the butt area, just a few inches ahead of the handle.

.................

I respect opinions but believe in proof. I'll try some other ways to load a rod with and without running guides and see if I can find a significant difference in the bend of the rod. No matter how you deflect or load a hot-shot blank I do not believe you could get it to break anywhere near the butt.

I personally broke about 200 rod blanks during the research and testing for the RodMaker article on rod breakage. So I'm offering proof, not opinion. No less than 12 rod and blank manufacturers now use that article in their warranty departments to facilitate their personnel making determinations as to why returned rods had broken.

If you load a hot shot blank to overload failure, you will note that the tip section will be straight and any flex will be in the butt. It will break somewhere in the lower 1/3rd of the blank, typically just a few inches above the handle. The only way to break a rod in the upper area from any sort of overload is to high-stick it. Otherwise, all blanks are designed to transfer the bulk of any load to the butt area. The more you load a rod, the flatter the tip area becomes and the more flex you'll have in the butt area.

............

the fewer guides you try to use, the more critical guide spacing becomes..one or two more guides than standard makes guide spacing less critical..

ben belote Wrote:
-------------------------------------------------------
> the fewer guides you try to use, the more critical
> guide spacing becomes..one or two more guides than
> standard makes guide spacing less critical..


This is correct. And also why you want to use no more guides than necessary, but why you have to use good placement when you do this.

And when we go back to the idea of something like a Hot Shot blank - what would be the point of having all that power in the butt, if the tip is going to break before you can get to all that power further down? Load a Hot Shot blank to failure and the tip will be straight - the butt will be where all the flex is.

..........