Nice tie and a new rabbit hole is always fun to explore! I am not a traditional Spey fly tier but would love to find a reasonably priced copy of Shewey's book or a library copy. (just ordered on Amazon for $22)
Found this online at Maine fly fish, I cannot gauge accuracy of article or if Shewey covers it in his book. James, please keep this post updated I am feeling the gravitational pull of this rabbit hole.
The ribs were the one place where those ghillies showed off a bit and opted for some flair. But even there, there was some functional genius. The traditional Speys all featured at least two ribs, and some had four or more. A main rib of flat silver or gold tinsel widely spaced was primary. The gaps between each turn featured a narrower flat or twisted tinsel of the opposite color, and/or in some later patterns, a strand of bright silk floss. Always, a final counter rib of twisted gold or silver tinsel was wound on after the hackle in the reverse direction of the hackle to bind it down and keep the fly fishable if the hackle stem broke. When working with that many ribs, precision is paramount. If the gap in the main rib between turns 2 and 3 varies even a little from the gap between turns 1 and 2, the mistake is only magnified by the addition of the secondary and tertiary ribs. When ribbing a traditional Spey, you had to get it exactly right from start to finish, or the look would be ruined. There were no cheeks or herl butts to hide the blemishes, no gaudy and intricate wings to draw the eye up away from the body.
What struck me most when I first started reading about the old Speys was the emphasis placed on widely spaced ribs. Some period sources don’t specify the proper number of turns, but those that do mention two to four turns for a rib. At some point early in my fly tying days, I was told that salmon and steelhead flies must have five turns of ribbing. At first, I thought it was pretty arbitrary. Why not six or four, or some other number depending on the length of the hook and width of the ribbing material? What was so special about five? It was only after looking at lots and lots and lots of flies tied by people who will always be way better tyers than me, did I see that five turns of appropriately sized material made for the most aesthetically pleasing proportions. It also kept a nice balance of tinsel color versus body color. A red body was still definitely red, but accented nicely with gold or silver flash if there were five turns. Where hackle was wound butted up against that rib, it created an optimal balance between sparse and full as well.
So why only three or four (at most) turns of the main rib on a Spey fly? Here’s where the functional genius comes in. In order not to obscure the rib, palmered hackle is best placed against the rear or trailing edge of the rib. So, the number of turns of rib dictates the number of turns of hackle. The extra long coque tail and heron hackles of the old Speys had to be kept reasonably sparse, or they would interfere with the sink rate of the fly. Too much hackle also dampens the action in the water, as barbs clump together and move less freely, especially in swifter waters like the Spey. Placing five turns of ribbing, and thus five turns of hackle, on the extra short body of a Spey fly would have tilted the sparse/full balance too heavily to the full side.
Although nobody today knows for sure why the early Speyside tyers included additional ribs running parallel to the hackle and main rib, I think it may have had something to do with the lesser number of turns of main rib. The waters of the Spey are “peaty”; not cloudy, but certainly tinted. One way to increase visibility in the stained water without adding bulk to flies was to add more flash in the form of tinsel ribs. Second, third, or even fourth ribs wound between and counter to the main rib were an obvious solution. I strongly suspect that the ghillies may have been hedging their bets a bit as well. Period literature reveals a great deal of theorizing about (even an obsession with) the merits of silver or gold tinsels in a given set of conditions. Strong opinions were voiced streamside concerning whether it was a “gold day” or a “silver day.” Given that many of the old Spey patterns differ principally only in tinsel colors and configurations, there’s plenty of evidence in the flies themselves that the choice of gold or silver was a serious matter. A fly sporting both simply covered more bases.