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What Line wt. is my Rod?

Rod Building 
12K views 17 replies 9 participants last post by  Mumbles 
#1 ·
Nothing important. Just trying to find out what line to use on my unmarked graphite fly rod. There is supposed to be a way to determine line weight for cane rods, but I can't find it; and guess the two, plus glass, are all done the same way.

Short of a SWAG wave in the sky can determining line weight be done easily and more accurately?

I don't think it is critical, but the rod is 6'6", two piece, and bottom slime green in color.

Your help is appreciated, and thanks,
Bruce
 
#3 ·
I should learn how to Google properly.... I found the following at: https://suite.io/rob-wagner/30ya2c4

It was more complicated than I thought. I think mine is a different green than yours Steve. However, after beating the air, my SWAG is 2 or 3, also. I will do Rob's test and report back.

How to Determine the Weight of a Fly Rod
The weight of a fly rod refers to how heavy a line is needed to make it cast properly. It is vital to know this when choosing fly line, and easy to figure out.

by Rob Wagner


Most fly rods have the vitals - length, action and weight - written on the rod itself, just above the grip. However, with older or custom-made rods, the information may be missing or unclear. In that case, there is an easy way to calculate rod weight and hence the proper fly line to use with the rod.

Materials Needed to Calculate Fly Rod Weight
    • measuring tape
    • clamp
    • paper clip
    • metal washers
    • accurate scale
Determining the Weight of a Fly Rod
1. Measure the entire rod, minus the grip, in inches. In other words, measure from the very top of the grip (not the butt end, but the other end) to the skinny end of the rod. Mark down the measurement and then divide by 10. For a rod measuring 90 inches from grip to tip, that would give a final number of 9. This represents 10% of the rod length, excluding grip.

2. Clamp the rod tightly to a table, putting the clamp on the cork grip and letting the rest of the rod extend out over the edge of the table. No part of the rod except the cork grip should touch the table.

3. Measure the distance between the very tip of the rod and the floor. Now subtract from that the figure derived in Step 1. Continuing with this example, if the rod tip is exactly 36 inches above the floor, subtracting 9 gives a new number of 25 inches.

4. Pry a paper clip partially open and hang it from the tip of the rod, then begin hanging washers on the paper clip until the rod tip bends down to the mark calculated in Step 3. For the rod in this example, one would add weight until the tip was exactly 25 inches from the floor.

5. Remove the paper clip from the rod and measure the weight of the the paper clip and all of the washers used in bending the rod. This weight must be in grams. Accurate scales can usually be found at grocery or hardware stores and post offices.

6. Divide the weight by the number from Step 1. If the paper clip and washers in our example weighed 30 grams, one would divide that by 9 to get roughly 3.3 grams per inch. This is called the stiffness ratio.

7. Find the stiffness ratio and its corresponding line weight in the following chart, and you now know the weight of the rod. In the example used, the rod turns out to be an 8 weight and should be used with 8 weight line.

Stiffness Ratio: (grams/inch) .............Recommended Line Weight (Rod Weight)

1.4 - 1.6.................................................................3

1.6 - 1.9................................................................ 4

1.0 - 2.2 ................................................................5

2.2 - 2.6.................................................................6

2.6 - 3.0.................................................................7

3.0 - 3.5.................................................................8

3.5 - 4.15...............................................................9

4.15 - 5.0............................................................10

5.0 - 5.9................................................................11

While this method requires a little bit of work and some mathematics, it provides a simple way to pinpoint the exact weight of a fly rod. Armed with that information, a fly angler can then make an informed decision when purchasing a matching line.
 
#12 ·
I've been following this discussion and have used the info to test a heavier rod in my collection. It was marked as an 8/9 weight but tested as an 11 weight. That might explain why the WFSink TIP does not cast well. Hard to get the line up and flying. Now my question: is there a way to measure a fly line to determine its weight?
 
#7 ·
I fiddled and did a really good job of getting into a mess. Matthew, I may need to go back to "Common Cents". It's pretty heady stuff for me however. So, I persisted with Rob Wagner... I can get by when reading menus.

To reiterate: The rod is graphite, called 6'6", and I did find the weight on the tip section at the plug--3/4wt. I measured the length and the rod is 7'0" from "Made in China" stamp to tip-top. I decided to challenge Rob W., i.e., whoever designed the length, proportion, weight, and table system anyway; the Chinese, and; myself.

Working length = 73" / 10 = 7.3" It required 15.05g to sag 7.3 inches. 15.05 / 7.3 = 2.06 stiffness ratio. 2.06 falls within the stiffness ratio range of 1.0 to 2.2 on the Chart. Therefore, we have a rod in the upper range of 5wt. I won't try to guess the action.

Stupid Chinese. Stupid me for waving sticks and making predictions--earlier guesstimate of 2/3. Steve K. wins, sight unseen. Take me with when you go to the casino, huh?

Postscript: Getting a reverse Wells (?) to stick solid using a bar clamp is tricky. Otherwise, this test is easy ... if you have a decent gram scale. Still, starting with a 5wt line, we need to fiddle some more with other lines and find a good balance. This brings up a final question: Is it worth buying various lines for a rod that cost less than one fly line?

Thanks, everyone.
Bruce
 
#9 ·
I’ve been using this system on all my builds over the last few years. I call it the quick and dirty since it is easier and faster than CCS but does not yield as much data, just line weight. Someone could come up with an action angle scale if they had some “truth data”. Once I get done running the numbers I go out back and test cast at the resulting line weight, one under, and one over using lines of same taper and verified to be AFTMA compliant using my scale. I’ve found this test to be very accurate.

A couple of comments from my experience. Using metric length measurements makes this a bit easier. Just as with CCS, if you allow the rod to teeter at all under load (butt cap to lift off the bench) your numbers will be off on the light side. I always double check to make sure it has not moved after loading.
 
#10 ·
I've been using this system on all my builds over the last few years. I call it the quick and dirty since it is easier and faster than CCS but does not yield as much data, just line weight.

Once I get done running the numbers I go out back and test cast at the resulting line weight, one under, and one over using lines of same taper and verified to be AFTMA compliant using my scale. I've found this test to be very accurate.
For my purposes, having as much information determined as possible is always an advantage. At my current level of experience knowing the static rod weight, spares me from the expense of a couple rolls of fishing line.

[/QUOTE]Someone could come up with an action angle scale if they had some "truth data".[/QUOTE]

I think there are numerous people who want an "action scale". I do. I picked up the second bargain rod thinking it was a softer action and lighter weight. It actually turned out the opposite of the second rod tested.

BTW, I am learning the formatting of posting, too.

Bruce
 
#11 ·
After doing the rod weight test I decided to return it to Sportsman's Warehouse, because:

1. It reminds me too much of that initial half-inch, or so, of surface slime in the bottom of dead water. The part that might still be active and green. But, most alternate rods are gradations of the slime color that is become anaerobic. Those rods are black, grey, and even tend toward blue. The colors are just too scummy. I just have a mental image of our freshly $50 groomed shi-tzu/poodle mutt racing away in terror when another dog at the local dog park wanted to play. Buster ran into a pond and got stuck in the putrid bottom slime. There was no way to clean him... and all those colors.....

2. It was a red-tag bargain and sometimes bargains refuse to be anything but a bargain. It was the same weight of the other rod I have; and, I want to create a whole new set of reels, or spools, for a different weight of rod and fishing. I just have a lot of money (VISA credit) burning a big hole....

So, I returned the slime green rod for a margarine stick. Eagle Claw Featherlight. It's a nice color. An OK color. Maybe, some day I will paint it chartreuse.
 
#13 ·
Roger, other than casting, I don't know of a bench method for determining line weight. Others on the forum may know, and can help.

Some line manufacturer's will note specific line weight variance from AFTMA(?) standards, but are rarely more specific than "half-line/full line" difference. A good shop will have a variety of lines spooled up and you can test them before committing to the investment. Most dedicated fly shops have skilled staff able to help.
 
#14 ·
For CCS just mount the rod horizontally at the grip and add enough weight to the tip to deflect it 26" (measure the distance from the ground to the middle of the grip, then subtract 26". This is the distance from the ground to the tip with weight attached). For weight I use a large fish hook through a plastic bag, then add nuts/washers until it is properly deflected.
Post the weight and I'll calculate the ERN for you.
 
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