Ed those are some wonderful looking bows you've got there. I admire your skill, and I fully respect that you guys have experience with extremely reflexed bows, and I do not. The most extreme bow I've ever made ended up with a little over 6" of reflex and was 60" long. Not so extreme. So I'm not telling you guys you're wrong, I'm just looking to understand better. I'm reading your post closely.
To tiller out a bow such as C that you showed it would be like tillering a wildcat.Linear and lateral stability would be an issue especially more so if the bow was very narrow.I've been there and done that and it an be done.
Tillering bow C would be a nightmare, for sure. I can't imagine the process of even just getting it to brace. I had enough trouble getting my bow to brace. The fact that people can tiller a bow like bow C without computer controlled machines producing nearly full draw ready limbs straight off the factory floor... it's amazing that you say it's possible.
The difficulty of tillering makes sense to me, because a huge part of the tillering process has to happen while the tips are beyond the handle, and are pointing away from the direction the string wants to pull them, leading to intense lateral instability.
Quite frustrating really with no added benefit but still very unstable as Badger stated even after tillering it stable.
If I'm understanding you right, this is where you lose me a little bit. If we picture bow C on a tillering tree, once you get to the stage where you can finally pull those tips down past the handle (which would be when you've tillered it like 60% of the way to full draw
), then I imagine things become much easier and much more stable. I am very familiar with this transition from the reflexed bows I have made. In the tillering tree, while the tips are above the handle, the bow is doing all kinds of weird things and desperately wanting to flip. After the tips are below, ahh sigh of relief, things are in control now. From that transition point on, the farther you draw it, the more stable it becomes. That's the point that I'd expect a reflexed non-recurved bow to start behaving more like a sane bow. I hope I'm understanding you right, but I think you're telling me this isn't the case with bow C. You're telling me it would remain unstable even after the tips are past the handle and pointing down. I'm having a hard time understanding why that would be.
In fact the bow would stack at the end of the draw then.A bow such as C should have retro bent tips pointing straight down the last 6" in the profile you've shown.
I'm not sure what you mean by tips pointing straight down. If you mean that a bow like C would automatically come out whip tillered, I'd have to disagree. If it came out whip tillered, then I'd just say whoever tillered it did it wrong. They should've left more material on the outer limbs. It's perfectly possible to have bow C come out to the circular full draw profile I've drawn.
I do agree that bow C would stack more than many recurved bows. Recurves, of course, add a lot more energy storage. But I think C would stack less than A and B, which was the point of the exercise. To distill out the effect of reflex without muddying the water with extra variables like recurves.
But sure. Add recurves to all 3 bows and they'll all stack less, and bow C will still stack less than the other two. I'd imagine that something like bow C with big recurves would start getting in to levels of energy storage that would make compound bows start worrying about competition. But that would be crazy unstable.
My expectation would be this: for bows with recurves, especially recurves that are extreme enough to point away from the belly side at brace (a.k.a. string contact somewhere along the limb), more string tension means less lateral stability. To a high degree. The string is trying hard to pull that recurve out of line. So for recurves, the more reflex the less stable in use.
Conversely, for a bow with no recurves, I wouldn't expect increased string tension to have nearly the same effect destabilizing effects in use. It will have some destabilizing effects, just because of the general increased tension everywhere. Like if I imagine limbs that are nearly as thick as they are wide, then yeah, there will be problems. But I wouldn't expect it to be too much for a reasonably wide limb. And to take that farther, if bow C were to taper in width like a modern fg recurve, with very wide and thin limbs staying quite wide and thin all the way to the tips.. I have a hard time imagining lateral problems. Perhaps my expectations just drastically underestimate the forces involved?
But in short, I'd expect recurves to have an extremely destabilizing effect on a high tension bow. However, I do see that shortening the working area will have a stabilizing effect. I'm with you guys there. But I'd think you'd only really need to do that to counter the destabilization from recruves. In addition, you can shorten the working area without recurves.
But every extremely reflexed bow I've ever seen has had some form of recurve. If the tips aren't pointing away from the belly at brace (string contact), then they're pretty damn close to being in line with the string. This makes sense because people are chasing that power. But it also means it makes sense that people have this association of more reflex = a bow with less lateral stability to a high degree. If you know of or have made any extremely reflexed bows with no recurve, I'd love to see them and to know more about them and how they failed.
A boat shape type profile with the reflex mostly on the outer half of bow will be much easier.With not so much up close reflex to tiller coming from the fades but if reflex is in fades more so should be put in the outer half of limbs yet.
More reflex can be put on the last 6" of these bows here too with a bit more benefit but this profile is easier for me to brace with just a primitive stringer the way it is without the use of tepeliks.They are still very stable bows.The extra reflex on the outer limbs puts more pressure or strain closer to the handle which is stiff which helps stabilize the limbs better.Making static recurves have the same effect of pressure on a self bow.
I fully understand you here and my expectations agree.
It's interesting to note that it would be possible to make a bow that had your boat shape when unbraced, but had a perfectly circular tiller (identical to bow C) at full draw. What would your thoughts on that be?
Again, I respect your experience with this, I'm just contrasting my expectations with what you're saying in hopes that I can understand better. I'm actually wondering if our thoughts on this are as different as they seem to be.
