It's always a good idea to have a plan and, indeed, I had a great plan in mind when I first sat down to tie the Two Bit Stone. I reasoned that since my Two Bit Hooker is constantly on the end of my tippet when there are a lot of mayfly-size aquatic insects around, creating a larger version to imitate a Golden Stone was a logical progression. I even thought it would be easy. But then, like so many times before, reality reared its ugly head. While I thought I would be able to simply alter the colors and the size and come up with a slim, heavy representation of a Golden Stone, what I first ended up with was really just a yellow version of the standard Two Bit Hooker. It was too short, too fat, and looked too cartoonish to be acceptable. I hate it when that happens.
It's this process of trial and error with thread and feathers that I love so much about fly design. Honestly, the further the final version is from my original idea, the more excited I am, because I know I allowed myself to just go with the flow and actually improve the pattern instead of just sticking to a rigid game plan.
Obviously, I wanted a fly that would be heavy, so working off the design of the original Two Bit Hooker, I started with two tungsten beads. After several prototypes, the profile still wasn't right and I considered going a whole new direction and using just a single bead, when it occurred to me to try using a longer hook to stretch the fly out. Using a 2XL Tiemco 5262 gave me a longer chassis to more closely match the naturals' profile, but beta versions tied with two beads were still too blocky and stout.
I began perusing pictures of Golden Stone nymphs to refresh my memory of their overall shape and size. A Golden Stonefly is a pretty cylindrical critter when you really take a close look. It's no wonder flies like Pat's Rubber Legs are so popular. A stonefly, at its essence, is really just a tube with some legs, tails, and antennae flailing about in the water, and chenille patterns really do match that basic outline pretty well.
But I am a fly tier above all else, and I just can't settle for something so simple, even if it is effective. I wanted something smaller in the size 12 to 16 range anyway, so I could fish it on a dropper, and match with the juvenile Golden Stones that are common year-round in Colorado, so I kept at it.
With the cylindrical idea in mind, it occurred to me to use three beads to finish the thorax, divide the legs, and create inherent weight in the fly. Using an appropriately sized bead for the hook size made the fly a bit too thick in my opinion so I downsized the beads and now use the next size down per hook size to streamline the thorax. To clarify, on a size 12 stone, I use a 7/64" bead, the size I would typically use for a size 14 fly.
It was this single final alteration that made all the difference. While my first few versions were tied with three tungsten beads, about ten minutes of fishing proved that you can indeed make a fly too heavy. Triple-tungsten bombs dragged down even large foam Charlie Boy Hoppers, as they plummeted straight down to the center of the earth. Nearly all of them ended up stuck in the river bottom.
The final version uses a single tungsten bead paired with two of brass to create just enough weight to drift the fly low in the water column, but stay off the sticks and rocks along the bottom. I also carry a few in my box tied with two tungsten and one brass bead, as a heavier version for deep, fast-water fishing, but have decided that three tungsten beads are just too much in most scenarios.
Along the way I played with a few different tail materials, finally settling on gold-dyed wild turkey biots. These biots have beautiful mottling and being somewhat thinner and softer than goose biots, are more durable and less prone to breakage. Small black wire created a perfect, three-dimensional rib over the abdomen and a wingcase of Golden Stone Thin Skin topped with a single strand of 1/100" Mirage Flashabou added for the final accent completed the front end.
The thorax is Superfine Dry Fly Dubbing because it can be applied sparsely and twisted tight to the thread, allowing me to fill the gaps between the beads and build a solid foundation for the Whiting Coq de León hen saddle hackle legs. Softer dubbings just didn't cut it as they compressed too much under the thread turns.
To toughen the body, magnify the flash and rib, as well as to help create the overall shape of the fly, I finish the Two Bit Stone with a head-to-tail coat of Solarez UV resin along the top surface of the fly. The finished product is accurate, slim, heavy, and durable. That was my plan all along.
Charlie Craven co-owns Charlie's Fly Box in Arvada, Colorado. His latest book is Tying Nymphs: Essential Flies and Techniques for the Top Patterns (Stackpole Books/Headwater Books, 2016).