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I am designing my next bow and I am thinking of the reflex/deflex design. I have read every book on archery I can find. I have two bows under my belt that turned out pretty well except I am not satisfied with anything short of perfection. My question is, how much reflex and how much deflex? When does a longbow begin to be a recurve? What is that perfect point of good control and good speed? Don't most recurves have pretty good stability now days? I realize that this is a loaded question but I need to ask it anyway. I might make two bows a longbow and a recurve but my first love is the longbow. Robin hood and Howard Hill and Byron Ferguson can't be wrong:) I will be using bamboo on the back with a maple core and belly. I might throw in a piece of glass down the middle to stabilize things a bit and to add more speed. How long should the riser/handle area be? Man those are a ton of questions. Thank you for your time, it is a very valuable commodity.

Mike
 

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Until you have all the answers for yourself, why not simply find a bow that you like, and make an approximation of the working design?

You can add details yourself - that's the "art" of bowmaking and should be your own input, but the basic working outline doesn;t need to be something every bowmaker has to re-invent each time.
 

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I suppose a set of loaded questions might merit loaded answers.

First, one might consider what the purpose of the duoflex is. Then it might become clearer how things might be combined in a way that more closely reflects your design criteria.

If you've had much experience with bows typical of the Howard Hill design, you have encountered "kick", the discernable vibration in the handle when the string arrests the forward motion of the limbs. This can become annoying after awhile. The purpose of deflexing the limbs is to reduce the kick so it's no longer discernable. The deflexing is done near the handle where its kick dampening effect is most pronounced.

Unfortunately, deflexing has another consequence, which is reducing the cast of the bow since it's already partially drawn beyond the usual rest position of the limbs when it's braced in effect, similar to when the bow follows the string. To compensate for this and restore the lost cast, the limbs can be reflexed near the tips. This is why one might notice the curves are essentially complementary, that is they're roughly equal but opposite.

When the bow is braced then, one can't discern the curves because they effectively cancel each other out. The duoflex bow for all practical purposes is then effectively a conventional long, flatbow with the kick essentially removed and the lost cast restored.

This is somewhat different than a recurve in the sense that the recurve effectively starts out as a short bow that becomes longer as one draws it. Thus, it is able to store energy in a way that's somewhat different than a straight or duoflexed flatbow. The recurves operate at a more acute angle away from the shooter than the rest of limbs and hence mimic a longer straight bow in a way.

The sihas on an Asiatic bow do much the same thing but actually participate in the energy storage as soon as the draw starts while recurves only start participating when the string breaks contact with the limbs near the tips.

This translates into a roughly 10-15 percent increase in velocity, all other things being equal, over a straight or duoflexed flatbow.

Now there's some dispute about how much velocity enhancement duoflexing might impart to a flatbow. I suspect it's not very much if it exists at all but it's possible it does exist, at least in principle, because of the angular differences at which the limbs are bent might store a little more energy than the straight limbs would.

I hope this has muddied the pond enough to keep things loaded.
 

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warder1268,
I'm not fond of longbows, due to the amount of hand shock they impart to the shooter. I've shot recurves for years and enjoy the speed, smooth shooting and general ease of "mastering" this type of bow.

However, I was at Cloverdale, In. at one of the Traditional National shoots and had the opportunity to shoot a flatbow with a reflex/ deflex limb design and loved it. I shot part of the 3-D course with it and should have purchased the bow, in retrospect. It was smooth, quiet and accurate. If I were to consider the purchase of a longbow, the reflex/ deflex limb design is something that I'd look for in a bow design.

Good hunting, Bowhunter57
 
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