Determining a rods test curve

I have a custom built rod that I have had for a few years and the builder never marked the test curve on the rod. Does anyone know how I can determine what it is?

As far as I am aware, the test curve is determined by how much weight it takes to make the rod bend through 90 degrees.

I've seen it done by clamping the butt of the rod in a work bench, then attachnig weights to the tip of the rod until the tip is pointing straight down at the floor. It it takes 2lbs of weight to do this, then the test curve is 2lb.

Hope this helps. I'm sure I will be corrected if I am wrong on anything.

Adrian

Adrian you are correct don't worry. It may be better to get somebody to hold the rod at the butt section flat on a table and then adding the weight slowly though. I wouldn't like to put enough pressure on a rod through a vice if it was going to take a 2lb weight to bend it. It would probably crush the section being held.

Kevan

Thanks guys I will involve the wife this evening. Do you think I could achieve the same effect by attaching it to my weight scales and pulling it around to 90 Deg and then looking at the readout? I must say I have visions of my blank expiring in the process.

Regards Sean

I don't think with modern rods that the test curve loading means all that much. Not only that but it is very difficult to establish what the test curve actually is.

If you bend the rod by pulling at right angles as is instructed, you will find that you cannot quite make the tip form a true tangent to the line on the vast majority of rods.

The test curve is supposed to be a guide to the power of the rod and to the strength of line you can use with it. Many modern rods have complex compound tapers which send this theory out of the door.

In theory: 5 x TCL = optimum line strength where TCL is test curve loading. Therefore if a rod has a TCL of 2 lbs the optimum line strength is 10 lbs. This is not so.

The range of line strength you can use with a rod is dependant more on the action and length of a rod. For example you can put more pressure on a fish with a 10 foot rod with a through action than you can with a 13 foot rod with a fast taper action, whilst retaining a curve of resilience. In this case the TCL on the 13 footer can be more that the TCL on the 10 footer.

The whole business is in fact quite complex. A rod that is perfect for long casting may be quite useless for playing big fish for example.

The whole business is in fact quite complex. A rod that is perfect for long casting may be quite useless for playing big fish for example.

That is so true Ron. Unfortunately it is often the case with the cheaper carp rods that are aimed at the newcomer to carp fishing.

You should be able to determine the casting weight from the TC though. Roughly for every 1lb of TC equates to one ounce maximum of lead. I know some people go over this limit but surely you cannot be getting the most out of the rod if you do?

Kevan

Actually it's not as simple as that. The distance you can cast a concentrated mass is influenced in a fishing rod by several parameters. However probably most important is the SPEED OF RECOVERY FROM BENDING.

A fast taper rod of quite a low TC will cast further than a slow taper rod with a high TC.

Anyone who wants to get into this sort of technology should contact me direct.

Ron, as usual you're correct in what you're saying but I think all Sean wanted was to mark the TC on his rod.
I just hope it isn't a Les Moncrieff Longbow with reverse taper butt!!! LOL.

I understand that Richard.

But the point I am trying to make is why should we be bothered with test curves at all? There should, I believe, be some other sort of measure of how a fishing rod's performance can be assessed.

Thanks for all the input. Richard had it in one, almost. What I am trying to do is determine the weight of a lure/spinner my rod can safely handle. I can probably do it by feel, this wil give me a good idea but knowing the upper and lower parameters is becoming more important as I fish with a wider range of lures now than I used to.
Regards Sean

Thats the best way Sean, by feel if you ask me.

Maybe manufacturers could designate their rods by way of safe casting weight instead. A t the same time they could include a safe shock leader breaking strain - if it was needed - to be used with the classes of weight.

Kevan

We are on the same wave length here Kevan. I made a similar suggestion about 3 years ago in Angling Star.

I used to use a pair Tricast 11' 1 1/4lb TC (sadly stolen in December 1994) which were marketed as M/L 3-8 this standing for Medium to Long Range 3-8lb Line. I have always wondered why more manufacturers didn't and don't provide similar information.

When my rods were stolen I spent ages finding replacements and I looked at everything available at the time in the range of 1 1/4 - 1 1/2lb TC. The range of actions of the various rods was enourmous. The TC was indicative of very little other than the relative power of a particulkar blank compared to other blanks in a particular range.

IMO you should never buy a rod till you have tried it. i stuck to that rule when replaceing the tricasts and eventually bought Harrison 1 1/2's which are the best bit of kit I have ever purchased in 35 years of fishing.