Connecting your fly line to backing means joining the thin, high-capacity line on your reel to the thicker fly line with a connection strong enough to survive a big fish and clean enough to run through your guides, and the best way to do it is a loop-to-loop cat's paw. A fly line runs about a hundred feet, so to fight a hundred pound tarpon or a big snook you need several hundred yards of backing behind it, and that backing-to-fly-line connection is crucial. In this How 2 Tuesday I bring in Nick Davis from 239 Flies, who spools reels all day, to show how he does it.
Watch and listen now: press play in the player above and follow along.
The strongest, cleanest connection is a loop-to-loop join using a cat's paw. Your backing has a small Bimini-twist loop and your fly line has a welded loop. Pull the Bimini loop into a bite, pass the leading end through the fly line's loop, then run the fly line spool through the Bimini loop twice. Pull it tight and you get a cat's paw with two points of contact, which looks like an X. That double contact keeps the backing from digging through the fly line coating when you fight a big fish.
A cat's paw is a loop-to-loop connection where one loop wraps through the other twice instead of once, creating two points of contact that look like an X. Nick Davis from 239 Flies uses it to join backing to fly line because it pulls the loop together at the bottom rather than letting a single strand dig into the fly line on each side. The payoff is that when you hook a big fish, or go to swap the fly line, your braided backing will not cut through the coating of the fly line.
As small as possible while still fitting over the fly line spool. Most spools are around four inches in diameter, so a loop about five to eight inches long is plenty. You want it small because an oversized Bimini loop can get pulled into a weird shape and catch on the rod tip or a snake guide as it runs through, and as Nick says, if it can go wrong in fly fishing, it will go wrong. Keep it just big enough to pass the spool and no bigger.
You use the same loop-to-loop idea, but only run the leader through once instead of twice, since you are not doing a cat's paw with a tapered leader. Run a tapered leader sized to your rod, twenty pound for an eight weight, thirty pound for a nine or ten, forty pound for an eleven or twelve, through the fly line loop and back through itself. From there tie on about eighteen inches of fluorocarbon tippet, and your finished leader runs around ten to ten and a half feet to the fly.
For most fishing, yes. Modern welded loops are very strong and most anglers trust them completely. Rio was one of the first companies to add them, and it took years for people to come around, but the technology is now reliable enough that you rarely see one fail. In the old days anglers would snip the loop off and build their own with twenty or twelve pound mono and a double, triple, or quadruple nail knot. Today the welded loop is the way to go for everyday fishing.
Because it spreads the load across two points of contact instead of one. With a single pass, the thin backing can dig into the fly line coating on each side, and if you hook something big, or go to change your line, the braid can slice right through. The cat's paw pulls the loop together at the bottom with that X pattern, so the backing grips evenly and cannot cut through. You will not lose a ten pound bonefish on your eight weight because your braid sawed through the coating.
Here are the steps Nick walks through. We cover the details in the episode and on the video above.
We unpack each of these in the episode. Press play in the player above.
The whole reason for running the spool through twice is to create two points of contact, that X pattern, so the backing cannot dig into the fly line coating. With a single pass, the thin braid saws into the line on each side, and when you hook a big fish or go to change your line, it can cut right through. Nick demonstrates the difference in the episode, so press play in the player above.
Most fly lines now come with a welded loop, and it is very strong, though it took years for anglers to trust it. In the old days we would snip it off and tie our own loop with twenty pound mason and a double or triple nail knot, convinced it was stronger. Nick and I get into when you can trust the welded loop and when you might not in the episode, so press play in the player above.
On the front end you do not use a cat's paw, just one pass through and back through itself with a tapered leader sized to your rod, then about eighteen inches of fluorocarbon tippet. Nick lays out his exact leader formulas for eight through twelve weights in the episode, so press play in the player above.
This is so much easier than it used to be. The cat's paw to the backing and a simple loop-to-loop to the leader give you a connection you can trust on big fish, and you can swap fly lines in a couple of minutes.
If you want Nick to rig your reel, look him up at 239 Flies on Instagram. Press play in the player above.
How 2 Tuesday is my weekly series where I break down one fishing skill at a time, from knots and casting to gear, tactics, and the habits that make you a better angler. Watch and listen to every How 2 Tuesday episode from Tom Rowland.
Nick Davis · 239 Flies · Brian Butts · backing · fly line · Bimini twist · cat's paw · welded loop · nail knot · Rio · tapered leader · fluorocarbon tippet · How 2 Tuesday · Saltwater Experience
I'm Tom Rowland, a professional fishing guide based in the Florida Keys, host of the Tom Rowland Podcast, and the longtime host of the Saltwater Experience television show. On the podcast's How 2 Tuesday series I break down one practical skill or lesson at a time, from fishing technique and gear to the habits that make you a better angler, in short, focused episodes you can put to use right away.
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