Interesting article here from Kirk Deeter, on a conversation with Sage rod designer Jerry Siem, who was making the point that rod size is best related to fly size not the fish size.
But the leap, by Deeter and those commenting was that this required you to buy more rods _ is really a leap too far and in the wrong direction.
For most of us our first rod is a basic entry level 9′ 5wt, a choice which will handle most normal fly fishing tasks. Depending how acquisitory a person. the next question is usually another rod: either a better 5wt or a more fun rod. Which is what Jerry was pointing out.
If you want another rod: figure out what job you want it for, and the flies you are going to use, rather than buying a rod for bigger fish or one which you simply might like. I confess to having a couple of fun rod purchases which don’t come out of the tube very often at all.
And its not like you need a rod for every size fly from a #32 to 4/0. As I said that 5wt is the best choice for most trout tasks, though out at the edges, very small flies or very heavy ones, there may be better tools for the job. But’s only when you start wanting to push the envelop in technique that you need another weight rod.
Six weights are generally the tool of choice for smallmouth, but you can get a lot done with a 5. It’s when you need longer casts with heavy crawdads or bigger poppers that you will come up short. It’s the same with trout: you can cast size 4 hoppers with a 5wt, but you will do it easier with a 6wt.
So you might think a 7wt is about right which is a smart call when building a rod collection for different tasks. Sevens are the quiet achiever of the fly rod world, over shadowed by its bigger cousin the 8wt.
I confess to being addicted to 8wts. For years I fished an 8wt and a 6wt for everything from trout in the Rockies, salmon and trout in Alaska, to roosters in Baja and Bass in Arkansas. In hindsight though a 5wt was probably a better choice, but the 8wt can do so many things.
An 8wt will handle big wind resistant freshwater poppers, for bass or salmon, and all the Clousers and mid size baitfish patterns you need for inshore salt, and the sinking lines and big trout streamers we fish on the White. And an 8wt can still fish those #6 or #8 buggers and Zoo Cougars, and cast them a lot further than your 6wt.