Drawforce Question.

[kawika b]

If I wanted to make up for speed loss due to a shorter draw length, I would make up for 1" of draw loss by adding 3# of draw weight right? I'm not entirely sure about the numbers but I think it went something like that.

[vermonster13]

4% per inch.

[kawika b]

So if a bow is rated at "X" fps for 50#@28" at and I drew 27" I would have to increase the draw weight by 4% to compensate?

[kawika b]

So I'd need to draw 52#@27" to equal to the same performance of the 50#@28" bow? I know that drawlength/powerstroke is king but the above numbers would be close,,, right?

Please help,,, my head hurts from all this thinking now.

[Orion]

Yep. You're in the ball park. A pound or two one way or the other isn't going to make much difference.

[kawika b]

So using the math of: draw weight - 4% for every inch under the AMO rating would be better than the usual 3#per inch rule of thumb,,, right?

[Bjorn]

Kawika the paperwork that comes with every ACS details the draw force for every inch from 23", or so on up to 28" maybe more............I am at work right now but when I get home in the next hour I'll look it up.
That is the kind of thing you are looking for-right?

[kawika b]

Pretty much that Bjorn. I need to go look for my ACS's paperwork,,, never thought to referance that.

[Bjorn]

Hi Kawika, I got busy tillering my Dryad bow blank and forgot all about everything else. But it is pretty much finished now and looks good.
Here are the ACS numbers:
42#@25; 44#@26; 47#@27; 50#@28; 53#@29; 56#@30.
Sorry for the delay,
Bjorn

[kawika b]

Thanks Bjorn. Dryad eh? If you ever need to unload you ACS's you know where to find me.

[Bjorn]

I'm afraid my ACS's are too gentle for your Gorilla arms, Kawika!

[bvalentine002]

Originally posted by kawika b:
If I wanted to make up for speed loss due to a shorter draw length, I would make up for 1" of draw loss by adding 3# of draw weight right? I'm not entirely sure about the numbers but I think it went something like that.

I read this differently...with the same answer.
What I have heard is:
1" = (approx.) 6 fps (all else being equal)
1# = (approx.) 2 fps (all else being equal)

So, you need to go up by 3# to match the speed of 1".

I have a 31-32" draw, so we knuckle draggers have a built-in advantage in the FPS department (but the drawebacks exist too...like finding arrows long enough).

-Brett