There are several good things about a pure deflex bow. Efficiency being the best. However, it looses energy storage. A deflex bow is just like a car engine with lower compression ratio. It doesnt require much power to deliver its work. It's a solid reliable, under stressed bow that shoots a heavy arrow quite well. It also is less likely to take set as it bends less.
Now consider this engine with low power, and you wanna boost its performance. Enter the turbo charger. Reflex is like the turbo, perhaps even with a little lag as the tips must catch up to the rest of the limb once released. You take that low compression and shove air down its throat causing it to compress more. Now it has high efficiency AND its power goes up because its storing more energy. The tip/string angle changes providing better leverage, the bend radius increases as you get to the mid limb, and string tension at brace increases.
So, tillering a RD bow to look in profile at FD as a D bow you loose all the benefits of the reflex and are left with a deflexed bow that's like a turbo charged engine with the waist gate stuck open.
I mostly agree with you, but you're skipping over what I've been trying to say. Reflex is beneficial for non-deflexed bows too. It is not special to the D/R design. This turbo charger can be effective on many engines. When D/R bows hold their own against fully reflexed bows (even with modern materials with no set, and even when the fully reflexed bows have stiff outer limbs too) you can't explain the D/R bow's excellence by just pointing at the reflexed parts. That's racing two cars with turbo chargers, and saying one won because it had a turbo charger. Deflexed handles offer performance advantages of their own. Those advantages are there whether the reflex is or not.
Sidenote: D/R designs aren't under stressed unless they're overbuilt. Bending a thick piece of wood a little bit stresses the wood just as much as bending a thin piece of wood a lot. You can damage the wood either way. D/R bows aren't inherently less stressed, they're just easier to overbuild without looking overbuilt. (This is at full draw. They are indeed less stressed at brace)
My drawing on page 2
is a D shaped bow with a deflexed handle. Those drawings are carefully drawn with the necessary measurements. I didn't just make it up and draw things where I wanted them to be. I think the differences in lever length and the string angle are important. This helps with energy storage. They're better than a straight bow's too. The advantage may not be enough to make up for the lack of string tension, but they're still there and worth keeping in mind.
It's also worth keeping in mind here that a braced bow's profile doesn't tell you much about its unbraced profile. You could unstring a deflex handled D bow to find its limbs curl up like a Korean horn bow once free. It being a deflexed handled D bow doesn't actually tell you that it has low string tension, or that its limbs aren't reflexed when unbraced. I'd actually love to see more deflex handled horn bows with extreme reflex in the limbs. I suspect a lot of potential lies there.
There seems to be a lack of interest in what I'm saying here, but I don't think it's smoke. I'm open to being wrong, so if my logic is flawed I'd love for someone to point out why. No one who disagrees has really engaged with me yet.
