Will shortening the bowstring raise the draw weight?

[Grey Taylor]

I was recently told at a shoot that the bow's draw weight may be raised by shortening the string.
I don't think this is true but I didn't have enough information behind my thought to counter the statement.
So, beside the fact that radically changing the brace height with a too-short string isn't necessarily a good idea, why or why not will the bow's draw weight be affected by the string length?

Guy

[Stumpkiller]

No.  The bow will still draw the same amount at 28" as marked.  It will feel like more because you have less distance to pull to get you there.


Furnulum pani nolo?  I don't want a small oven?

[Grey Taylor]

Thanks, Charlie.
It is supposed to mean, "I don't need a toaster." It sounded interesting when I ran across it on the Internet and seemed to be a gentle poke to those who itemize a list of every bit of archery gear they own.
Not that there is anything wrong with that if it's what you're in to    

Guy

[Ragnarok Forge]

Were they talking about adjusting the brace height or a shorter string.   Raising and lowering brace height effectively changes the bow weight in very small amounts.  This is what allows you to fine tune your bow to your arrows.  What is actually happening is that your increasing or decreasing the string travel which changes the amount of energy released into the arrow when shot. So while the draw weight did not change,  the result is the same as if it did.

[Mark Baker]

I disagree, and believe it will indeed raise your bow weight.   By shortening the string, you have effectively flexed the limbs into draw, before actually drawing the bow.   Any added draw you make only adds to this.   Although it adds a little weight, it actually makes your bow shoot slower, by reducing the "stroke" of the bow limbs.   So, the rule of thumb, to get the "most" from any given trad bow, is to brace the bow as low as possible, but still achieve good arrow flight.  Your bow will shoot faster, at less draw weight.

[Grey Taylor]

Clay, the individual was talking about using a shorter bowstring.
I suspect this will be an interesting discussion...

Guy

[Balding Kansan]

I agree with stumpkiller.

An "X" pound bow @ 28" will always be "X" @ 28" even though the brace height changed. I would suspect it would stack heavily the last few inches of draw making it feel heavier.

[sidebuster]

One sure way to find out is to pull the bow on the bow scale before and after the brace height adjustment.  The truth will be in the pudding.

[Ragnarok Forge]

Sidebuster has it right.  It is all opinion until the scale comes out.  Someone have a bow scale?

[lil red rooster]

I have seen it first hand.  Changing the brace height effects the preload on the the limbs.  It does indeed change the weight.  And more than you might think.  Mark has it right though.  The increased weight is off balanced by the decrease in the power stroke.  This is partly the reason that Asiatic bows are so efficient.  The limbs are preloaded so much.  Take a recurve and measure it at a 6", 7", and 8" brace.  You will be surprised at the difference.

[Jeff Strubberg]

It does raise the draw wieght, but its a very, very marginal difference.  Think a pound or so for a 2" change in brace height.

It also makes your bow less efficient.

[Bjorn]

My scale is not sensitive enough to pick it up............I suspect it is a temporary gain and there is a loss too. Shorter string raises the preload a bit but it is still the same when pulled to 28". The string time has been reduced so there is less force on the arrow.

[Breeze430]

Isn't "stack" increased draw weight?? I think so..

With a string for a 56" recurve on a 58" recurve I get less than a pound difference on a 42 pound bow.

[Stumpkiller]

Stack is when the rate of change increases sharply.  Say you gain 2 pounds per inch as you pull the string back from 26" to 27", and another 2# for 27" to 28."  But if you need 5# to pull from 28" to 29" the bow has "stacked" once you got past 28".

Depending on tip design, some bows stack like hitting a wall and others can be more manageable.  It can be a good thing if your bow stacks right as you hit anchor.  

If you look at some of the graphs and polars on bow tests that last bit of draw can also add a lot of speed and cast to an arrow.  That's why some guys think a Bear Kodiak Hunter is a snoozer and others a great bow.  Get those tips working and it does all right.

[kevgsp]

A shorter string/higher brace height WILL increase the draw weight.  By how much?....depends on many factors. Small adjustments may not be noticeable.

To make it easier to understand imagine a string 6-8" too short for your bow. When u draw back to your anchor the limbs will be bending more than with a string the correct length...hence higher draw weight.

[Al Dean]

Shorter string raises draw weight at 28" because of the angle of attack between string and limbs.  With shorter string limbs are actually bent more.  Depending on the bow it can raise weight noticably.

[StickBowManMI]

I think that this is a very interesting concept and I agree with Sidebuster that the scales will tell the truth. Sure hope that someone does use the scale and post the results for all of us to read.