Advantages of Over and Under Lining Tenkara Rods

All Western Fly Rods come with a Line Weight Designation, like a 9 foot rod for a 5 Wt. Line, for example. T-rods do not have any information like that on the box. But it would be most helpful if they did. About as close as we can get (in English) is the designations of L L for level Line Rods, L T for rods designed to cast either Level or Tapered Lines. Generally speaking, L L Line rods are soft and Full Flexed, and have the lowest Penny Ratings and would include a very soft 4:6 or a 5:5 soft to stiff rod segment description. 6:4 rods could go either way but, 7:3 and 8:2 rods would be Tip-Flexed, Fast Action, Casting Rods.

As the line is cast, it is the energy stored in the rod that catapults the weight of the line out in the desired direction. The Western Fly Line Numbering System corresponds to the weight (in grains) of 30 feet of line less the taper, which for a 5 Wt. Line would be 140 Grains. Tenkara Level FC lines are also Numbered: Size - # 1.5; Dia in Inches - .0081; Lb Test - 6 Lb. Test - Approximately
# 2 .0093; 8 Lb.
# 2.5 .0102; 10 Lb.
# 3 .0112; 12 Lb.
# 3.5 .0122; 14 Lb.
# 4 .0130; 16 Lb.
# 4.5 .0138; 18 Lb. Test

But there is no, as far as I know, correlating weight standard or measurement for T-lines. It stands to reason that more line will weigh more than less line will, and thicker line will weigh more than thinner lines do. And the best rod casting characteristics will fall within the line weight range the rod was designed to cast most efficiently, even though we have no exact way of knowing what that range will be. But, we can determine a lot by feeling how the rod is throwing the line we are casting, and that’s where over and under lining the rod comes into play.

Say you are fishing a small, stair stepped, plunge pool stream, where not only are the casts short, but the length of the pools requires a very short line to be used or the fly ends up in the rocks and in the bushes. Your 3.3 m rod casts best with a # 3 line as long as the rod is long but, that’s too long for the pools you are fishing, and the rod casts poorly with the shorter lines of 5, 6, 7 and 8 feet because these shorter lines do not weigh enough to load your rod properly. The solution is to Over Line the rod by going to a bigger, heaver, line size. One that has enough weight to load the rod properly in the shorter line lengths this kind of water demands. Because the line is so short, the heavier line will not compromise holding your line up and off of the water because it does not weigh all that much in such short lengths.

At the other end of things, lets say you need very long lines to fool really spooky fish, requiring lines of 6 to 10 meters or more in length, and your 3.6 m long rod casts best with a # 3.5 line as long as the rod is long, + 4’ of tippet. Ten meters of a #3.5 line is going to over load the rod and you will not be able to get the distance or accuracy you need. But 10 meters of # 2.5 line will load your rod well enough to get the distance and cast accuracy needed if, (and this is a very BIG IF) your casting is good enough to use all the line’s potential. To get there just takes time and a lot of practice but, you can do it if you work at it. We all Can.


Very logical analysis, Karl. I haven’t really considered varying the line size when changing length for casting performance. About 90% of the time I probably use a line about rod length +/- 1’ and then add a few feet of tippet as my starting point. I tend to think about line size based on penny rating and on wind or if I’m trying to reach farther and need to go lighter to keep the line off the water…but that was to reduce sag and not based on rod loading. Much of the time I’m using various sized bead heads so I tend to go with a lighter line anyway. You’ve got me thinking…thanks for bringing this up!

In the past, I tried using a heavier line (#4 or #5) when fishing small streams and creeks to try to load the rod better. But I found no difference or advantage over my standard #3 level line. The casts, drifts, and all other parameters were the same. I stopped making heavier, short lines and now just use my standard #3. As for longer lines, I’ve experimented with that too. But my conclusions are mixed. I still need more data.


I think you’re on the right track and herewith is a possible shortcut to successfully creating a database for line size versus length. A gram scale weighs to three decimal points. Might it be useful to weigh your ideal line weight so as to easily replicate it with another line size?

Such scales are small and inexpensive. I bought one on Amazon for fourteen bucks.

Barry Kustin

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In my hand, which implies that individual (personal) variances in casting techniques will change things, the Mizuchi rod casts better, for me and not necessarily everyone, with 3.5 lines. But, like Tom, I generally fish streams with # 3 lines, as well.

In defining line length, I only count the HiViz Line Length, starting at 5’, 7’, 9, 11 and on through 13 feet to fish different stream widths and pool lengths. The transition sections and tippet are “clear”. But I also carry the 7 thru 13 foot lines in size 3.5 as well. In flowing waters, I fish Dry Flies all most exclusively, which will probably differ a lot from what most of you are doing. For streams, it’s 2 to 3 feet of 6X Tippet for me - FC.

My go to line for Stillwaters is the Dragontail’s Floating Level PVC T-line of rod length, followed by a tapered leader, consisting of: 24” of 16 Lb. RIO Salmon/Steelhead Nylon Tippet material; 18” of Valcan Sanyo # 3.5 FC T-line; followed by 12” of # 2.5 Valcan LowViz FC T-line; followed by 9” of 8 Lb. test Cabela’s NoViz FC Spinning Line and Finished off with 3’ of 5X FC Tippet. Because I fish dry flies, I find that FC butt sections sink too fast for dry flies.

For really windy conditions on lakes and ponds, I fish a 3 m, Tungsten Wire Line that Esoteric Tackle sells in different lengths, with a short tapered leader, starting with 24” of # 2.5 Valcan FC T-line; 18” of 8 Lb. test FC, and 3 feet of 5X FC Tippet material. The Tungsten Wire Line really cuts through the wind and sinks like a rock. Strikes are not seen but felt through your line and your rod.

The Transition Sections go between the HiViz Level Lines and Tippet, they are clear, 18” of 8 Lb. test FC and 9” of 6 Lb. test FC, plus 36” of 5 or 6X FC Tippet material.

I did not put up this post to, necessarily, convince anyone to change what they are doing but to foster some thought and experimentation on what we are doing with our lines and how we fish them. Tenkara Addict was disappointed with the way the FoxFire Rod cast in its longest length - 9’ 3”. He said he prefers stiffer and faster rods. He was fishing a # 3.5 line. If he cast that rod with a # 2.5 line, the rod would feel faster and stiffer. The rod is designed to be a short, soft, Level Line Rod, so it needs a light level line to be used on it to realize its best performance potential. I think we can all agree that that makes since…Karl.


I do have an electronic reloading scale that I checked line weights with in the past, mostly the differences between tapered mono nylon furled lines, furled FC lines, level FC lines and tapered 000 Wt. PVC Floating Fly Lines. Unfortunately, I didn’t keep the records. I remember, they were all pretty light in weight and I found it more practical to go by the feeling of how well each individual line loaded and cast on a target rod by feel than by recording the numbers. Unsatisfactory lines were retired and the good ones were labeled for size, material and length, coiled and carried in Zip/Lock book Leader Wallets, with plastic sign dividers cut to fit each Zip/Lock Bag to carry 2 Lines in each pouch. The divider’s line descriptions are written in with H2O proof felt marking pens. This carry system is much more convent, organized and compact than carrying your lines on line spools.

The lines are coiled from the tippet end first, around your hand, thumb holding the end against the first joint on your first finger, wrapping the line around your hand into the crease in your palm below your little finger and under our line-securing thumb until all but about a foot of line is coiled. The remainder is spiraled around the coil to secure the line, and the coiled line is dropped/slid into its line pouch zip/lock bag line wallet pouch and zipped close.

To put a coiled line into use, you open the zip/lock, take the line coil out, un-wrap all but 1 of the coil securing wraps, stick your compressed hand in the coil hole and expand your hand against the coil and pull the line off of the coil while wobbling your coil hand back and forth.

Pulling an an arm length of line back and forth over your shoulders or legs 10 to 20 times (until you feel the Heat) will take all the coil set out of your line and it will lay and cast very strait.

I prefer the Girth-Hitch Loop attachment with a Double-Overhand Lilian Knot Attachment method. The double overhand knot is easier to untie and more secure than a single over hand knot would be

In general line parameters or so tied to fishing style, conditions, and the fly weight at the end that trying to designate a line weight to a rod is futile.

Most folk want as light a line as possible for presentation but not everybody. Just that detail illustrates the issue. Personal preference.

Some of this is covered in other threads. Flouro, mono, braid, and furled of the same weight and length will all cast differently because of diameter… wind resistence.

The rod load is in the casting stroke not the line weight. Yes you need some wieght but i think it has more to do with enough weight to turn the tippet and fly over than loading the rod.


G, I mostly agree with what you are saying. Chris Stewart believes the T-angler is best served by matching his line to the rod he is casting. I would just like to know what line the rod maker designed that rod to cast.

Chris attended a Tenkara Gathering in Itoshiro, Japan in 2011, where a survey was conducted, every responding angler fished with a Level FC Line, with the majority choosing the # 3 size. Understandably, I believe this applies to Japanese made rods. The Chinese made rods, generally, will do better with heavier lines.

And another factor that comes into this is line stiffness, which is why Tenkara source FC lines cast better than general purpose made FC lines will, because the FC T-lines are stiffer. G, have you ever cast with a Tungsten Tenkara Line? Tungsten Wire Lines are at the top of the stiffness scale and they cast like a bullet. The Tungsten line I have Mics out @ 0.007” in DIA. And it is nearly twice as heavy as lead. Soft line materials use up much of their casting momentum in turning themselves, the tippet and the fly over, so there is a lot more that goes into casting than just the line’s weight, you are sure right about that.

I have not fished tungsten lines or any wire lines.

2.5 -4 LL are the zone that most people fish regardless of rod or line length. The # choice has more to do with control of fly than rod load. Most rods will throw really heavy lines without an issue and may be easier to cast, but then will produce drag on presentation. Most folk will develop a skill for casting light lines to gain better fly control onthe water. The line choice is not related to rod loading, but rather a factor of the lightest the angler can manage for the conditions and other preferences.

In general we all can load most tenkara rods with without any line. The line is just there to present the fly and land the fish. That 2.5 -4 LL range has the perfect density and wind resistence for the task of presenting a typical kebari. If you had heavier or larger profile flies like a streamer, you may need a heavier line, but that has nothing to do with rod load.

Conditions we fish factor too. Like if i live in a windy location i would opt for a heavier line, than of I lived in an area that had little wind. It would not make sense for a rod to dictate the optimal line weight as the choice is not tied to the rod at all.


To what extent does the minuscule weight of an additional .001 inch in diameter over 7-8 feet of line, compare to that of the rod itself? While pretty much non-existent in the graphite western rod sector, “self-loading” is well known amongst the bamboo and fiberglass aficionados. I feel the same holds true to some extent with my tenkara rods. So if the rod seems to cast well at standard length with a #3 line, then I don’t use heavier lines as lengths shorten.

<this was left out of my reply, no idea why>

Wind - now that’s another matter altogether….


FWIW I also think the weight of the line is marginal in the way the rod behaves. Even if I can “feel” the line when casting, my understanding of casting mechanics is that the rod loads much more under its own weight and elasticity than under the weight of the line. Casting the rod with no line kinda demonstrates what I’m trying to say.

Scott and Oliver, this is just something you will just have to try for yourselves to see if it makes a difference You can feel. It is up to you how many thousandths in DIA you want to up the line diameter. All that I can say is that it makes a difference for me with the rods I am fishing. Keep doing things any way you like, doesn’t matter to me one way or the other. I just put this out there for those who it might help. Obviously, it will be of no help to you. And that’s OK too, it’s your fishing, do it any way you like.

For those who might be interested, here are the Tenkara Level Line Specs, subject to individual line maker tolerances:

2.5 - 0.272mm - 0.011"

3.0 - 0.296mm - 0.012"

3.5 - 0.320mm - 0.013"

4.5 - 0.365mm - 0.015"


Good topic. I’ve been gravitating towards lighter lines for both tenkara techniques and nymphing with fixed-line rods as well as with rod/reel nymphing.

There is a lot to experiment with – the casting is one thing, the cross-section-subject-to-wind and the sag/weight of the line is another. For me, I am primarily looking to figure out which I like to optimize for and continue to fish with more of a compromise in other aspects – I hate changing lines out when on the water.

So far, I’ve found that a lot of experimentation doesn’t necessarily give the answers I want, but at least it helps me to detect when the rigging/equipment is more of a limitation than my skill (long lines in tight quarters in wind is an easy problem to detect and correct).

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Hi Lance, I think, a lot of the time, we learn more from our failures than we do from our successes. So failures are not always really failures because you get to learn what does not work. When the first thing you put on scores and you have a many fish catching day, we tend to revel in our successes with out much learning taking place. And other than the pattern that caught all those fish, not a lot else is recalled.


I agree, Karl.

I get to fish almost daily, so when I get over catching enough, I like to try new things. That’s when I push for versatility rather than brute force but less widely applicable.
To me that is the really rewarding part. It can be finer tippet/lighter flies, broader depths, etc. But you don’t make much progress if the count is all you’re after all the time. It is often successful just because it isn’t something you’ve done much before … sometimes it is a flop, but low expectations are the key to happiness!

I did a little more research on a rod’s abilities to cast all by itself with out the line having much weight to add to the casting motions.

Rod: Nissin SP 390, 12" 11" long, 1.5 Oz. in weight. RFI 2.05 and it is an 8 penny rod. If any rod ought to be able to cast due to it’s own weigh and elasticity, you would think this very soft rod would be a good candidate.

Line: A rod length of Kmart Merc. Cotton Thread, Size 50, no tippet (why waste it).

Results: The rod would not cast this line! As a matter of fact, the line became a hopeless bird’s nest in an unbelievable short length of time. This is an experiment anyone of you can try for yourselves that demonstrates the importance of the line’s weight to the rod’s casting action. As can be seen from the Line Specifications above, each line size is exactly 1/1000th of an inch apart. If 1/1000" does not make a difference, why did the line makers set up the line sizing system the way they did? The number 4 line was omitted because I have never cast or fished with a number 4 Line. But, as can be seen with the Number 3 Line, the number 4 Line would Mic out @ 0.014".

Another interesting thing is that the Line Weight doubters complained about the heavier (thicker) lines being harder to hold up and off of the water when they went to heaver lines under windy conditions. And the reason FC Level T-Lines are preferred for wind and fishing in general is because FC line is about twice as heavy as the same diameter in Nylon Lines are. The idea that the rod can cast a line all on it’s own is false…Karl.