Bow design and development

[DC]

I was waiting for my turn at the range the other night and was looking at the bows. Not counting the compounds every bow there(except mine) was a FG recurve.( I can be a little slow sometimes ) Ignoring the FG part all the designs were deflexed recurves. Not one FG longbow and I know they made them when I was a kid. This got me thinking that somewhere in the past bow making companies must have done a lot of testing of various designs and all decided to make basically the same design. There must be a lot of data squirrelled away on the effect of various tests. Does anyone have access to any of this stuff? I realise that FG data won't be directly transferable to wood but a good design is a good design.

[Badger]

  That is an interesting question you are asking. Surprisingly little good data has been generated from bow making companies. They found designs that seem to get them up in the 90% of what is possible range and settled in. For the most part little details about things that can have small effects on performance have been ignored or have failed to be isolated. Some computer modeling programs available now seem to be making design a little easier as building hundreds of bows to test small things is not practical.

[DC]

I guess they aren't huge companies like GM that can afford to have a "Skunk Works" department constantly fiddling with stuff.

[bradsmith2010]

I have a feeling that a design that will please the masses,,is what you see,,
it is hard to apply alot of what you see to a wood bow,, just a differet beast,,Marc makes some deflex recurves and you can see that works,, but alot of great designs have been used for centuries as well,, that are not deflexed,,etc etc,,
the deflex may be the best design for fiberglass in general,, not sure about that,, maybe the most" popular "  right now,, alot of Native style bows were reflexed in the handle,, so something about that worked for them,,and thats how they made a living,,

[JNystrom]

I see the point of view is "what is the most accurate and fast arrow launching tool on open ground while standing in FITA position". Maybe a reflex-deflex is the best design for that. Or like said earlier it just pleases the masses. If you look at maybe the golden era of target archery, men shot a 6 feet longbow.

On my opinion the best bow design is the one that suits the purpose best. I wouldn't go hunting or shooting from horse back with a 6 foot longbow.

[bradsmith2010]

good point, what is best for the purpose at hand,, could vary quite a bit,,

[Stick Bender]

I think the claim to fame for the D/R bow is it can be pulled to full longer draws in a shorter package as compared to long bows , there is a ton of info on the long bows as you described by bowyers that are still making them particularly the guys making HH type or ASL type bows the D/R design in the FG world is generally considered a Hybrid type bow not a true static recurve & with modern material there just as fast or faster then static recurves ,I think Fred Bear spent most of his life trying to perfect the deflexed design the D/R design can be incredibly fast and accurate design ,I'm not sure how the FG data would be applicable to natural material designs the taper rates will be genraly more shallow and the material used capable of much higher stresses & mass properties , I think the reason you see similar designs is because of trial and error they just work it's hard to improve on history , another plus for the D/R design is the stack free FDC in a short package ! Just my 2 cents but I love the design because it's performance & feel !

[DC]

One thing that strikes me as odd is that FG will bend further and take more strain(correct me if I'm wrong) and yet any FG bow I saw(I searched a bit), even "long bows" have a deflexed handle which reduces strain. Makes me think that there is another advantage to deflexed handles.

[bradsmith2010]

like stick bender said,, stack free full draw curve,,

[DC]

Missed that, sorry. trying to read too fast. I would have thought that the stack-free part would come from the reflex rather than the deflex. I can see low stack being more than a comfort thing too. If you have a maximum draw of 40# and you can remove the stack portion it leaves room for the whole F/D curve to hump up, sorta. Do you have a theory why the deflex would contribute to low stack?

[Stick Bender]

Well there are probably many reasons that could be covered over a dozen threads on the topic by far smarter people then me ,but from a lay mans practical point one of my hunting bows Is a 60 in deflexed angular design it will not stack tell past 32 in. If I where pulling the same length strait long bow to my 31 in. Draw it would stack like crazy ,so DFC is much better with deflexing in the center & & reflexing the mid limb & tips allows a better string angle as opposed to a non deflexed design enhancing performance & that applies to any material used I would think ,great topic Don. Here is a FDC done by a friend of mine on that bow !

[PatM]

Deflex also more reliably eliminates shock and vibration.

 There's still plenty of glass bows of other design out there.  Your local scene just doesn't use them.

[DC]

SB-deflexed angular? What is the angular? And DFC? Sorry.
PatM-I didn't look real hard, just did a bit of surfing some the major manufacturers. It's hard enough getting around the compounds let alone finding info on traditional bows.

[Stick Bender]

If you deflex the center enough the strung profile becomes angular but with any design there are trade offs ,I just built a 64 in. of the same design it had great  performance but there is a point where the deflex is so great  that your brace height becomes so high that performance balances out ,I think the design performs best in shorter bows even with heavy arrows, I have been religiously playing with the design for a year and it's always about making another to find out what's best...lol a lot of little hidden quirks in the design but great bows ! It's like any thing with this bow making you just have to build and find out what works best at your draw & weight & materials !

[bradsmith2010]

full draw curve   fdc

I am working on a sinew recurve now,, but the handle is gonna be straigt or reflexed,, I just dont think I can get the tips to come forward enough with deflex in the handle,, but maybe I should try it on the next one,,