Line Weights and why it matters

Line Weights and why it matters

Paul Arden | Sunday, 18 September 2022

There is a discussion on the Board regarding line weighs and the AFFTA table, because as hopefully everyone should know by now, flylines are often overweight and sometimes by 1, 2 or even more ratings. In other words your 6WT line might really weigh a 7, 8 or more! While we can talk about how this has happened, what I really want to talk about is why it matters and is a serous problem… for fishing.

The first thing I should mention is choosing a line is not (or shouldn’t be!) about matching the line to the rod. It’s not about “rod loading”. The flyline should match the size and weight of flies being fished. The smaller the fly, the lighter the line. The heavier the fly, the heavier the line.

There is undoubtedly a cross-over (for example I might fish a size 10 fly on a 4, 5, 6 or 7WT line) and it’s possible of course to fish small flies on heavier tackle, less effectively and with care. It’s also possible to fish heavy flies on light tackle, also less effectively and while wearing a crash helmet.

And fishing is fishing. We break rules all the time. However the main significance of the flyline weight, is what is being turned over at the end of the leader.

Let’s take the 6WT line that I gave in the original example. I would use this line to fish flies down to size 16 and up to about a size 10 leaded. It will throw heavier and it will fish smaller, but that’s approximately the ideal fly size range.

An 8WT line on the other hand I use to cast size 1 and 1/0 Poppers here in the Jungle. It’s a streamer bashing rod for me. 2-3 inch weighted streamers. I’m not going to fish size 16 dry flies on it that’s for damned sure.

So if my 6 line weighs an 8 what am I supposed to do? Put the dry flies away and bring out the Dog Nobblers? 

And that’s why it’s a problem. It’s more of a problem than this too, because the heavier the line the less fishing sensitivity you have; the poorer the take detection, the less delicately the line lands and the thicker the tippet needs to be that you can comfortably fish.

Let’s talk tippets. On a six weight line 4lbs tippet would be pushing things for me. That’s about .14mm. I’ve done it but I have to be careful, especially if the fish are big which all mine are. Six pounds tippet is about right. Of course this should match fly size as well.

On an 8WT line I’ve never gone below 12lbs and I don’t want to tell you what’s on there right now. But we can call it 40. Not because I can pull 40lbs but that’s another story. More typically on an 8WT I would fish 12-16lbs tippet. Try putting that through the eye of a size 16 Funneldun.

So you can see there is a big difference between fishing a six and an eight weight line.

So why is it that lines are getting heavier? It’s quite simply because most anglers are buying the wrong rods. They are buying very stiff rods and then trying to find a line that “loads it” in their mind. It’s not about rod loading, everyone here on Sexyloops will tell you that, but it’s definitely about rod loading for your average fly caster!


So what’s the answer? Well of course everyone should buy the line first and then ask what rod to buy. That is how Sexyloops rods are designed. We take AFTTA conforming lines (not half up, not 1 or 2 line weights up, but bang on AFFTA) and design the rod to suit. And we make the 6WT and lighter models very good at casting short distances, in other words the first few rod lengths. That’s a fishing rod. 6WT and below in particular have to excel at short-lining.

But it’s not an ideal world and if you have bought a rod that has a 6 label but you feel the need to put an 8WT line through it, then you are just going leave the Trout alone and go fishing for Bass.

Many fly line manufacturers will tell you the weight of the first 30’ on their websites as well as overall head weight. Personally I think the first number is most important especially for close range fishing. The second number matters if you are throwing shooting heads or trying to catch fish that require binoculars to see. I would never buy a line without having this information.

For Hot Torpedo owners it’s easy; go by what the line actually weighs according to the AFFTA table and not by what it says on the box. It’s amazing how that works. It’s quite a novel idea and should be adopted by the rest of the industry at large.

Cheers, Paul