Its all fair dinkum sweetandsalt I know exactly where your coming from! This thread turned more into personal opinion than actual design ideas on the first page. Going into the math and trial and error involved in taper design would fly over the heads of alot of people. Myself to degree as well. To attempt to bring this back to a more scientific taper design aspect, is almost mute by know. But I'll try
and I should say that this is based on cane rods, I can only imagine the same would apply to a mandrel for graphite and glass rods.
The black line represents the dimensions or measurements of the given taper, starting low on the graph and ending as high as it does this rod would be consider "crisp" or fast in the cane world, maybe more progressive for arguments sake. The tip is soft yet responsive transitioning into a midsection that would appear somewhat soft but as you can see in the green line as well as in the black the slight rise in the stresses and "dip" in dimensions is a "soft spot", this is what will aid in dampening as well as provide the reserve power to help a 7'6" have some reach out and touch someone capability. Where you see the two lines abruptly turn away from each other is where a "swell" is added to keep the energy from escaping through the handle forcing it into the cast. To go into why the stresses do what they do is a lesson in "Garrison Math" I don't really want to go into. This taper is what I would consider a "hot rot" in terms of dry fly fishing, also keep in mind that cane will always feel "slower" to graphite and even glass due to the weight and its a natural material that doesn't like to be rushed. Some Gillum tapers have a reputation for being really fast and comparable to today's fast actioned rods. I'm not entirely sure if this helps or confuses the issue even more but it is my attempt to show what goes into taper design and what adds to the performance of a rod.
On a side note: Only Adipose, this will be your rod! Its getting there, I just needed a slight break from it after last nights straightening bonanza!
---------- Post added at 10:59 AM ---------- Previous post was at 10:27 AM ----------
For comparisons' sake here is the taper of a rod that could by all accounts be considered semi-parabolic although I'm not a fan of that term.
I left the swell out on this graph but its less severe than the first. This rod would feel very slow but the tip is fast moving into a softer mid and back into fast before the butt. The butt softens up a hair roughly 10 inches before the swell (this is why its a gem to roll cast). Where I feel this rod shines is roll casting and single hand spey. Dan, you would be shocked at what this little 88" rod can do! Maybe this misses the point as to why one rod out performs another but it provides a glimpse as to goes into a taper to get a certain level of performance.