Author Topic: American flat bow efficiency  (Read 732 times)

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Offline Fox

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American flat bow efficiency
« on: November 24, 2021, 07:21:21 pm »
How efficient is a American flat bow? With no set or reflex? What speeds would be expected from a 26Ē draw at 50# certainly enough to kill a deer. But how does this bow compare to a recurve or a R/D or a higher stress design?
Why must we make simple things so complicated?

Offline bownarra

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Re: American flat bow efficiency
« Reply #1 on: November 25, 2021, 02:32:53 am »
Wood can only take a certain amount of strain. The wood doesn't care what design it is in :) Unless you build a bow too wide/thin then they all see similar strain. Really that is the goal as a bowyer :)
An American flatbow is a slightly modified pyramid design - it will be plenty efficient if you do a good job of tillering.

Offline simk

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Re: American flat bow efficiency
« Reply #2 on: November 25, 2021, 04:52:38 am »
What is plenty?  ;)
In my bowmaking I found that a more complex design with somehow reflexed ends or pronounced levers will always outshoot a very classic straight bow by around 10fps. straight bows here go up to 175fps, more complex designs up to 185fps at 10gpp - these are my personal benchmarks.
« Last Edit: November 25, 2021, 04:57:40 am by simk »
---- learn something on every bow ----

Offline RyanY

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Re: American flat bow efficiency
« Reply #3 on: November 25, 2021, 06:54:44 am »
I canít answer the original question but I think itís possible that we havenít seen the best possible straight limbed bow performance. Weíve probably gotten very close but itís rare that designs are built and tillered in such a way that a limb has totally even strain along itís whole length. The typical American longbow taper of parallel limbs results in areas of higher and lower strain. Same with a typical straight line taper pyramid bow with circular tiller. I wonder if itís possible to squeeze out a few more fps with even, low strain resulting in no set with a perfectly matching width and tiller profile. Probably not 10fps more but who knows.
« Last Edit: November 25, 2021, 02:29:21 pm by RyanY »

Offline Badger

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Re: American flat bow efficiency
« Reply #4 on: November 25, 2021, 02:26:08 pm »
      I think about 165 fps at 26" draw with a 10 grain per pound arrow would be excellent for a straight limbed flatbow. One thing funny, in my experience I could take a good shooting 28" draw straightbow and test it at 26" and it would have a very big drop compared to a bow that had never been pulled past 26". It doesn't have to be that way but it usually is.