Primitive Archer

Main Discussion Area => Bows => Topic started by: stuckinthemud on January 26, 2018, 12:35:38 pm

Title: Deflex, why?
Post by: stuckinthemud on January 26, 2018, 12:35:38 pm
I don't want to hijack the splices thread but apart from aesthetics, what's the point in deflexing? I guess it de-stresses the centre, reducing set, allowing a short bow a longer draw-length? For those of us with tiny arms (I draw 24") is deflexing worth doing? Someone once said reflexed stave is natures gift to the bow builder, can't remember who, but it's a great quote.
Title: Re: Deflex, why?
Post by: vinemaplebows on January 26, 2018, 12:53:35 pm
Have you wondered why the majority of glass bows are deflexed? Build enough and you will understand why.
Title: Re: Deflex, why?
Post by: DC on January 26, 2018, 01:09:23 pm
I think it uses some of the storage space that is usually wasted in the brace height. Put another way normally you use 6" of tip travel to get to brace, if it's deflexed 2" you only use 4" of tip travel to get to brace. That leaves you with 2" more for draw length. If you don't need the draw length that means you can make the bow a little shorter and have less limb mass. Just my opinion/idea. They may be wrong.
Title: Re: Deflex, why?
Post by: gfugal on January 26, 2018, 01:11:23 pm
From my understanding it's three fold 1) it reduces the stress. Better a naturally deflexed bow than a bow with set. 2) it makes it easier to string and prevents it from flipping on you. This is especially important when you have large hooks. 3) it just looks cool.
Title: Re: Deflex, why?
Post by: DC on January 26, 2018, 01:23:36 pm
It's definitely easier to string. I have a couple of deflexed bows with large hooks that I can string using push/pull. If they weren't deflexed I would have to use a stringer.
Title: Re: Deflex, why?
Post by: PEARL DRUMS on January 26, 2018, 01:41:36 pm
There isn't a more smooth drawing, smooth shooting, quiet shooting and generally faster self bow made.
Title: Re: Deflex, why?
Post by: meanewood on January 26, 2018, 04:29:38 pm
Most logs I harvest are 50-70mm in diameter and may yield just one stave. If not straight and knots not being a factor, I choose the de-flexed side. Apart from some of the previous advantages already mentioned, I find it reduces the shock on the natural strings I use on Warbows above 100lbs.

The more the bow is reflexed toward the brace height, the required breaking strain is reduced dramatically, allowing for a breaking strain of 2 or 3 times draw weight instead of 4 or 5 times draw weight!

When you are making a linen or hemp string for a 150lb bow, you can keep the string diameter to 3mm instead of 4-5mm.

You don't lose any performance, it's not set and the shock load on the bow and the strings is reduced increasing their durability!
Title: Re: Deflex, why?
Post by: Springbuck on January 28, 2018, 08:06:13 pm
Just my opinion/idea. They may be wrong.

You don't give yourself enough credit! ;)
Title: Re: Deflex, why?
Post by: Badger on January 28, 2018, 08:12:55 pm
  The deflex also helps to smooth out the last several inches of draw and prevent stacking by improved string angles.
Title: Re: Deflex, why?
Post by: stuckinthemud on January 29, 2018, 04:27:14 am
Thanks guys, the comments have been really useful and I will make my next billet bow deflexed/reflexed to see what difference it makes but I'm guessing many of the comments  are about bows designed to draw 27"? My absolute max draw is 25 so is smoothing out the last few inches/increasing draw length and improving string angle as relevant to me?
Title: Re: Deflex, why?
Post by: bjrogg on January 29, 2018, 05:44:07 am
I'm thinking you'll probably get the most benefit from a slightly shorter bow for your short draw.
Bjrogg
Title: Re: Deflex, why?
Post by: gfugal on January 29, 2018, 10:34:09 am
I'm thinking you'll probably get the most benefit from a slightly shorter bow for your short draw.
Bjrogg
+1
The opposite is true for me. I have a 30-32 inch draw (not quite sure since I never had a bow that can draw that far). Reflexing my bows is pretty much a death sentence unless I do it just right. Haven't been successful yet, so deflexing might be a better option for someone like me than you.
Title: Re: Deflex, why?
Post by: simson on January 29, 2018, 11:38:38 am
I don't want to hijack the splices thread but apart from aesthetics, what's the point in deflexing? I guess it de-stresses the centre, reducing set, allowing a short bow a longer draw-length? For those of us with tiny arms (I draw 24") is deflexing worth doing? Someone once said reflexed stave is natures gift to the bow builder, can't remember who, but it's a great quote.

You have answered yourself.
And yes you can achieve a longer drawlength (given same bow length, same draw weight). But in my experience the limbs mass is a good higher than in an reflexed bow. This disadvantage can be compensated (at least a part) by making deflex/reflexed designs.