Bow Weight Versus Draw..?

[bow101]

Reading lots of stuff on here and other Bow forums.
Tell me something what is the correlation between draw lenght and weight.

(1) A bow having a draw of 30" with a weight of 40lbs.
(2) A bow having a draw of 26" with a weight of 50lbs.

Which bow will have more distance.......? And is it better to build a bow having a max draw lenght, in other words the more the better..?

[Hrothgar]

My guess is the bow pulling 50# is going to shoot further; given the arrows are the same weight and length.
The first pyramid bow I made was a 58" hickory. When I had it drawing about 60# at 22" I was anxious to see how it would shoot--the draw length was really pretty comfortable. Shot about a dozen arrows and they were really exploding, albeit a little inconsistant. For some reason I went ahead and tillered it down to 55# at 26. It shot more accurately/ consistant, but definitely was slower. If I could undo it, I would rather have kept the shorter, stronger draw.

[SLIMBOB]

I don't know the actual numbers, but I think the longer draw bow at 40# will have equal or greater cast than the shorter draw bow at 50#, all things being equal.  But all things aren't equal.  The longer draw length stores more energy, but set will increase as draw length increases which will have an effect.  You would need to go wider or longer to counter.  Things are getting father from equal.  Point is, design parameters would be different for the 2 bows.

[lostarrow]

Far too much not stated to make any conclusions. Are you looking for distance or  force upon impact? What length and weight are the arrows? what is the brace height? Are recurves or siyhas involved. What is the tiller shape?..............................Not sure what you are looking for for an answer.

[Pappy]

Not sure on the 40@30 /50@26 but I will say in all the shooting I do with others,
I shoot around 50@26 on most of my bows,I shoot with guys that shoot 50@28
and with the same arrow and the same weight bow in most cases the longer draw will have more cast and hit harder. Hard to be sure about all things being equal with selfbows but I do believe longer draw will give a harder shooting bow. In fact I am sure of that. My draw was 25 for a long time but have since
changed my form and now shoot around 26 and it has helped with penetration, not sure on cast ,never shoot for distance.
   Pappy

[BowEd]

Did a little bit of that through a chronograph with a fella one time.He shot a 60# bow at 25".I shot a 55# bow at 28".Both had equal profile.Both shot the same arrow.The 28" draw bow was faster even though it was 5# lighter.When you talk maximum draw length that's putting a bow to the edge.I'd rather have a bow that can take an over draw occasionally but still survive.You might break a lot of bows tillering them to maximum draw length all of the time,but when you get one it should be a screamer.

[BowEd]

I assume we are talking sef bows here.

[Del the cat]

It's the area under the force draw curve (FDC).
If you assume a linear FDC you could draw a couple of triangles and do some arithmetic to get the area of them.
Maybe I'll do it later over a cup of tea, but at the moment I have a bow heat treating and some insulated plasterboard to screw up to the ceiling . Heck I'm multitasking.
Oh gtg the kitchen timer tells me I gotta move that heatgun.
I'm back, I dun it.
If you have draw weight as height of the triangle and drawlength as the base line.
Area is half base x height so
26" draw 50# gives 13x50=650 inch pounds or whatever.
30" draw 40# gives 15x40=600 whatsits
So the 26" at 50 wins
Obviously this is just an approximation ignoring brace height and assuming poundage increases in a straight line from zero draw.
If you assume a 6" brace height and then draw going from zero to max you get a closer result.
26" now becomes 20/2 x 50 =500
30" now becomes 24/2x40=480
Del

[Pappy]

Del,Deep real deep.
   Pappy

[Sidewinder]

I'm glad there are guys out there that are as smart with math as Del, that way I don't have to be, lol. I suppose I should have paid more attention in my algebrea and geometry classes.
 My first answer would have been that the longer drawlength would have been equal to or greater than the shorter draw length and heavier weight, so I guess its just like in class, I would get the answer right but they would count it wrong because I needed to " show your work Mr Hartley".  Danny

[boughnut]

And I though I had some math skills with this bow making stuff.  Del you just made me feel dumb thanks   I would tend to think the longer draw because it is storing more energy and transfering more over the extra distance it is pushing the arrow but guess I am wrong.  I dont get into distance shooting at all though I like em close 20 yards and under but I am a hunter.  Still would be interesting to have maching designs at the draw weights and lenghts listed shot by same archer for a comparison.  Hate to say it but the test might work best with a fg bow just so there are not as many differances in wood quality and all that.

[bow101]

  Thanks guys i think that sums it up. So having read all the posts i would assume to allways go for the maximum draw pull one can achieve through proper tilling, bow design, etc...........etc..........

[Hrothgar]

Bow101, there is still one other factor--  make sure you have the correct length and spine on your arrows; otherwise your paradox is going to be really screwed up--just thought I would inject that 

[bow101]

I did not mention arrows because they really did not factor into the equation..........assuming all other variables are the same......such as the arrows been eqaul.

[BowEd]

More investigation and testing is done in the book Paul Comstock wrote the Bent Stick.He tests bows for distance shooting and talks a lot of maximum draw and full draw and the difference in performance of the bows used of different types of woods.