# Adjusting Brace Height...what will it do?



## SEC (Jul 13, 2007)

I have been reading that once you find the correctly spined arrows you can make adjustments in brace height to fine tune the arrow flight.

Trouble is...I have not been able to find what changing the brace height is supposed to actually do. Increase it/decrease it, what will it do?


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## howard hill jr (Aug 21, 2009)

If the brace height is too low it will over stress the limbs of the bow.
Withing the manufactures guide lines, raising the brace height will cause the bow to be less sensitive and more forgiving with the effect of shooting less hard because it is storing less energy (not much less). As the brace height is lowered the bow will shoot harder and sometimes become less forgiving and more sensitive to a bad release. It could get low enought for the string to start slapping your arm. The brace height should be kept with in the mfgr. recommendations unless you really know what you are doing.
If you are having problems tuning a bow brace height is one way to solve a problem. You are almost always better off raising a brace height rather than lowering it. Byron Fergason has an extreeeeemeeeeely high brace height.
He does this because it makes the bow more forgiving? and it does not shoot as hard so my guess is he makes up for it by using a heavy bow.
Thats the basics of it. Just another variable to play with to get you bow in or out of tune.


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## SEC (Jul 13, 2007)

Great, this is exactly what I was looking for...thank you for the response Howard Hill !!


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## kegan (Aug 28, 2006)

As a wooden bow shooter- I've seen the opposite. Lower brace heights are better (in terms of stress on the bow)- and higher will kill a bow.

But as for arrow spine: If you arrows are showing up weak (striking to the right for a right hander), then lower the brace height. If the arrows are striking stiff (left), raise the brace height.


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## BLACK WOLF (Aug 26, 2005)

SEC said:


> I have been reading that once you find the correctly spined arrows you can make adjustments in brace height to fine tune the arrow flight.
> 
> Trouble is...I have not been able to find what changing the brace height is supposed to actually do. Increase it/decrease it, what will it do?



A lower brace height requires a weaker spine and a higher brace height requires a stiffer spine...so if you have a bareshaft that is giving a slight stiff indication...increasing brace height may fix that problem and vice versa for a bareshaft stiff indication.

I recommend you always stay wthin the manufactures recommended brace height.

Ray


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## Two Blade (Jul 13, 2008)

Raising the brace height will increase your draw weight slightly and you will give you a slightly slower arrow and lowering your brace height will slightly lower your draw weight and give you a slightly faster arrow because the arrow stays on the string a little longer because of the lower brace height.


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## BowmanJay (Jan 1, 2007)

kegan said:


> As a wooden bow shooter- I've seen the opposite. Lower brace heights are better (in terms of stress on the bow)- and higher will kill a bow.
> 
> But as for arrow spine: If you arrows are showing up weak (striking to the right for a right hander), then lower the brace height. If the arrows are striking stiff (left), raise the brace height.


You hit it right on the head! This is how you fine tune your bow. It does work and I use it all the time....


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## Viper1 (Aug 21, 2003)

SEC - 

Raising the brace height will:

DECREASE the dynamic spine of the arrow (ie make it act softer)
INCREASE the draw weight 
DECREASE arrow speed

Lowering the brace height:

INCREASE the dynamic spine of the arrow (ie make it act stiffer)
DECREASE the draw weight 
INCREASE arrow speed

On a well made bow, changes in brace height should in no way affect the longevity of the bow, even if you go beyond manufacturers specs. 

Raising the brace height may in some cases make a bow more forgiving as it DECREASES string time and offset angle at departure at the cost of a few fps (OK, some times more than a few). BUT, arrow spine must be correct for the new brace height.

Viper1 out.


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## howard hill jr (Aug 21, 2009)

kegan said:


> As a wooden bow shooter- I've seen the opposite. Lower brace heights are better (in terms of stress on the bow)- and higher will kill a bow.
> 
> QUOTE]
> 
> You are right, I was thinking too far ahead of my typing.


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## ravensgait (Sep 23, 2006)

As usual Tony AKA Viper nailed it, one thing make sure when you are playing with the brace height , do it a few string twist at a time and keep track of what works best.. Randy


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## rattus58 (Jul 9, 2007)

I'm not a techy....

Most all of my bows have a much higher brace height than low to get "optimum" for me behavior and tune.... meaning the quiet I get.

I'm not into speed, but I'm into efficiency/quiet/accuracy and maybe someone can tell me that if because of my slightly longer draw length than many that the increased brace height is somehow more appropriate for a longer draw... Any ideas here?

Aloha...  :beer:


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## Viper1 (Aug 21, 2003)

Tom - 

Without knowing exactly "how" you shoot, if a higher brace height works "better" for you, it usually means your arrows are pr are acting slightly overspined. 

Also speculation: a longer draw length stores more energy in the limbs, a taller brace height allows less energy to get to the arrow. (The limbs are still holding energy at shock.) That may be a factor in why taller is quieter. 

Viper1 out.


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## WindWalker (Jan 23, 2005)

Sec:

Don't confuse yourself with all the "science." What works for one and for a particular bow is not universal; it's a starting point.

-Know your exact draw-length on that particular bow
-Scale the draw-length so you know the exact (dynamic) draw-weight on that particular bow.
-Match your (loaded) shaft spine you will use to your dynamic draw-weight on that bow.
-Set your nock height and brace height in acordance with the method of finger release you use, with best arrow flight and accuracy as your primary objective.
-If arrow performance and accuracy is spot on but noise level is greater than you hoped for, don't sacrifice arrow performance and accuracy to reduce the noise. Control the noise by other means.


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## Arcus (Jul 7, 2005)

Decreased speed - arrow acts weak
Increased speed - arrow acts stiff 

I'll bet I'm not the only one who finds this counter-intuitive (of course, my intuition has been off-base before). I know you've explained it before, but would you mind doing it once more?



Viper1 said:


> Raising the brace height will:
> 
> DECREASE the dynamic spine of the arrow (ie make it act softer)
> INCREASE the draw weight
> ...


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## Viper1 (Aug 21, 2003)

Arcus -

The change in spine requirements with changing brace height (which I assume is what you're referring to) has more to do with the INITIAL push from the bow and angle-off at departure than with the arrow's speed. And yes, it is counter intuitive. 

Brace height is a function a paradox, when you increase the BH, the arrow gets a harder push at release (due the the increase the draw weight) and therefore is forced to bend MORE - requiring or allowing for a STIFFER spine. The other part, the angle off at departure, has a similar effect to changing the degree of centershot, (taller BH - closer to CS) even though the Physics are a little more complicated.

See if this helps: 










The easiest thing to do is bareshaft your rig, then make drastic changes in the BH and see where the bareshafts go.

Viper1 out.


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## ravensgait (Sep 23, 2006)

WindWalker said:


> Sec:
> 
> Don't confuse yourself with all the "science." What works for one and for a particular bow is not universal; it's a starting point.
> 
> ...


That's a given we are talking about tuning a bow to get the best from it.

One thing that Rattus Mentioned was a higher brace for a longer draw, I have seen the same thing with some of my bows but for some reason I go for the opposite when looking for efficiency. I go for as low a brace height as I can get away with IE not pealing the skin off my arm lol

A lower brace height makes the bow touchier to shoot and a higher brace makes it more forgiving to shoot. So if you are a newbie or someone who doesn't have the greatest release then you want the higher side. But play with it till you find what works best. Sure you can take a bow and twist the string to the MFGs recommended Brace height and it will shoot fine with the right arrows but say one size arrow shows stiff and the next shows to soft. Sure you can add weight or take away weight of the arrow to get it shooting(This is why I think some shoot 200 grain heads lol) But if the arrow is close you likely can get it just right with a brace height adjustment .. Randy


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## Arcus (Jul 7, 2005)

Thanks. That helps.




Viper1 said:


> Arcus -
> 
> The change in spine requirements with changing brace height (which I assume is what you're referring to) has more to do with the INITIAL push from the bow and angle-off at departure than with the arrow's speed. And yes, it is counter intuitive.
> 
> ...


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## rattus58 (Jul 9, 2007)

Viper1 said:


> Tom -
> 
> Without knowing exactly "how" you shoot, if a higher brace height works "better" for you, it usually means your arrows are pr are acting slightly overspined.
> 
> ...


Interesting. I should probably write some of this stuff down like I do with my muzzleloader to have something "concrete" to refer too.

Thank you for both your observations and the diagram you posted... 

Much Aloha.. Tom  :beer:


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## Tajue17 (Aug 18, 2005)

with all my bows I start with the max brace height no matter what then I un twist the string only to fine tune my arrows as I'm bareshafting them,,, bows get noisy and my opinion they get less forgiving with a lower brace height so I sacrifice a little useless speed for a quiet bow and more forgiving bow..


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