# The best way to find your correct Draw Length.



## Luke Cool (Oct 16, 2015)

There are a lot of questions about Draw Length in this forum. But often, the answers come up short. It’s easy to understand the reason for this; it is difficult to describe a feeling. And short posts are easier to read and write, especially on a phone. This below is an attempt at a complete answer.

*Form:* Your bow string should be drawn to the edge of your mouth. You can see where a lower anchor point will give you a longer Draw Length. This is only one of the differences your form can make. There are many others. The Draw Length needs to fit your anatomy and form, not vice versa. If you strain into an uncomfortable position, you will never be at your best. Your form should feel natural and comfortable to you. It should take advantage of leverage and physics so that you are strong and stable in your stance.

*How to find your correct Draw Length: *Your draw length will change from bow to bow because a bow's axle to axle length and its cam size both affect the string angle during a draw. To start with, take your fingertip to fingertip measurement with your arms held apart, then divided this number by 2.5. Adjust the bow's draw length to the resulting number. This is a good place to begin, but now we have to do some fine tuning. Ideally, in a full draw, the string should be held firmly to the back wall with a few pounds of force. This increases stability and consistency. In a stance using a good comfortable relaxed form, draw the bow to the back wall. 
*1) *If your form feels compressed, the bow needs to be adjusted to a longer draw length. 
*2)* If you have trouble keeping the D-Loop from floating away from the back wall, the bow needs to be adjusted to a shorter draw length. 
*3)* If you’re comfortable, and you don’t feel like you are having adjust your form to fit the bow, leave the draw length where it is.

*The Draw Length adjustment:* Some bows are draw length specific. This means there is no adjustment on ether cam. On all bows, you can fine tune the DL by twisting cables. With this draw length specific scenario, if its DL does not fit, you can twisting cables if it’s close. If it’s not close, you will need to buy a set of appropriately sized cams. Most bows have a Draw Length adjustment on one or both cams. From here, the owner’s manual is the best source of information on how to make these adjustments. These adjustments have upper and lower limitations. If you are extra big or a lot smaller than average, not every bow can be adjusted to fit you.

*Draw Length Braces Height does not affect Draw Length:* Less Braces Height accelerates the arrow longer. This gives you extra speed that you didn't have to pay for with a more aggressive draw cycle. A smaller Braces Heights deknocks an arrow very close to the rest. This often causes a less forgiving launch. A higher preloading on the limbs fixes this problem.

*A release span adjustment:* This is not for adjusting draw length. Its purpose is to adjust the hand’s anchor point. The length of d-loop can also be used for this. Or both can be used to adjust the trigger location.

If You have any questions comments, any more information, or something you think I got wrong or missed, please post it.


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## ChillR66 (Jun 2, 2014)

Thanks for the post. I do have a question maybe you can help me with. Please understand, I'm not trying to change the focus of your post and don't mean to do that at all. For me, the info really brings up the question .... Does a right or wrong draw length, anchor point, the bow's poundage adjustment and/or string and cable twists affect a bow's valley or is the valley a constant of the cam design?

I have a Mathews HTX which is tuned to specs, shoots bullet holes thru paper with fletched arrows and bareshafts and shoots fine. It's a 70 lb bow backed down to 60 lbs, 28" draw length. I feel my draw length and anchor point are good and I really like the bow - I just wish it had more valley, it has very little. Does anything add to or take away from a bow's valley? Thanks.


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## chiefjason (Mar 22, 2016)

ChillR66 said:


> Does anything add to or take away from a bow's valley? Thanks.


Changing the DW can effect the DL which can effect the valley on some bows. My daughters Elite is like that. You can see her fighting it when we turned the weight up, so we dropped it back down.


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## boilerfarmer12 (Nov 22, 2011)

chiefjason said:


> Changing the DW can effect the DL which can effect the valley on some bows. My daughters Elite is like that. You can see her fighting it when we turned the weight up, so we dropped it back down.


That may not mean her DL is incorrect. It just may mean she can't handle the extra poundage. When u increase peak weight I also increase holding weight.


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## Luke Cool (Oct 16, 2015)

Some bows have an adjustable valley, most don't. I would never adjust my draw length to get a longer valley.
A short valley is normally not a problem if you have the bow set to the correct draw length.
In post one, I did say "in a full draw, the string should be held firmly against the back wall".
If you can not easily do this, the bow needs to be adjusted to a shorter draw length.
I have 3 bows with short valleys. 
After I found that holding the string firmly against the back wall increased my stability and consistency, I'v grown to like it.
Also, a shorter valley actually has a few big advantages. 
1) The arrow gets into the power stoke very quickly.
2) Because of the longer acceleration cycle, this gives you extra speed that you didn't have to pay for with a more aggressive draw cycle.
3) Because the arrow spends less time in the bow, it increases accuracy. The longer the arrow is in the bow, the more time the bow has to introduce errors to the arrow's trajectory.
4) If you use a cable driven drop rest, the arrow's acceleration will be a lot deeper into the power stoke when the rest drops.


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## Luke Cool (Oct 16, 2015)

chiefjason said:


> Changing the DW can effect the DL which can effect the valley on some bows.
> My daughters Elite is like that. You can see her fighting it when we turned the weight up, so we dropped it back down.


It does change, but it changes very little, and it does so in the opposite direction that you are thinking.
When you increase the draw weight, it decreases the brace height, there-for decreasing the draw length.
Post number 4 is at least partially correct. When you increase her draw weight, it probably compressed her form. 
Maybe she can handle the extra poundage, she will just need to make some adjustments to correct her form.


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## chiefjason (Mar 22, 2016)

I've had this happen twice. 

Wife's bow, Bear Finesse. I increased the DW and it nearly became unshootable for her. She could handle the increased weight, but any relaxing on her part and the cams started to release. Tinkered with the cable stops and the valley came back. Left the DW alone, she shoot's it fine. 

Daughters bow, Elite Spirit. Slight measured DL changes when DW increases, it get's shorter. At full draw she had the same issue. She could draw it and hold it, but any relaxing and the cams started to release. Limb stop bow, so I just lowered the DW. With the DL change it may have compressed her as well, but it certainly appeared that the valley was gone completely. Whether it was or not is irrelevant I guess since she said it felt like it was gone. 

Had a buddy over last week with an Elite Impulse 34. While tinkering around setting up his rest and fixing his peep we moved the limb stops to see how he liked it. Watching him shoot was just like watching my daughter and wife shoot. No valley, any relaxation on the shooters part and the cams started releasing. No DW change, just limb stop to change the valley. Changed it back after 2 shots. 

With my Elite Victory 39, Matthews Chill X, or my Matthews Conquest I can't recall it ever being an issue. Could be experience on my part, could be the bow, could be strength. 

In my way of thinking, if changing the DW changes the DL then it likely effects cam timing. Which is essentially what creates the valley. The sweet spot where the cams are easily held idle and neither moving from the draw or moving to fire. Could you tinker with it and fix that? I'm sure you could. But referring to the guys question, in my experience DW and DL changes can tweak the valley.


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## boilerfarmer12 (Nov 22, 2011)

chiefjason said:


> I've had this happen twice.
> 
> Had a buddy over last week with an Elite Impulse 34. While tinkering around setting up his rest and fixing his peep we moved the limb stops to see how he liked it. Watching him shoot was just like watching my daughter and wife shoot. No valley, any relaxation on the shooters part and the cams started releasing. No DW change, just limb stop to change the valley. Changed it back after 2 shots.
> 
> In my way of thinking, if changing the DW changes the DL then it likely effects cam timing. Which is essentially what creates the valley. The sweet spot where the cams are easily held idle and neither moving from the draw or moving to fire. Could you tinker with it and fix that? I'm sure you could. But referring to the guys question, in my experience DW and DL changes can tweak the valley.


Changing the DL may affect valley slightly. 

As far as moving the draw stops, uh yea that's what it does. it shortens the valley and essentially the draw which means you will hold of lot more weight. the cams aren't fully rotating.


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## chiefjason (Mar 22, 2016)

That was my point. The two issues appeared to be identical. One intentionally shortened the valley the other two incidentally shortened the valley.


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## Luke Cool (Oct 16, 2015)

chiefjason said:


> In my way of thinking, if changing the DW changes the DL then it likely effects cam timing. Which is essentially what creates the valley. The sweet spot where the cams are easily held idle and neither moving from the draw or moving to fire. Could you tinker with it and fix that? I'm sure you could. But referring to the guys question, in my experience DW and DL changes can tweak the valley.


If the cams are not synchronized, the let-off valley will be smaller.
The timing its self has a negligible affect on the let-off valley.
Changing the draw length changes the string angle during full draw. A longer DL makes a bigger valley. 
But little changes in any adjustment has a proportionally very small affect on the valley.
And all of the adjustments you are referring to, have a much more important function.
When I making any of these adjustments, the valley is of no concern to me.
I tweak them to their best setting for their main purpose, then live with the valley as is.
On both my BM32 and the Omen, PSE allows me to adjust the let-off valley; I choose to leave the valleys as small as possible.
So I guess my question to you is not can you, but should you use these important adjustments to tweak the valley?

And yes, when draw weight is increased, maintaining your correct form is a matter of acquired discipline.
Experience matters.


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## chiefjason (Mar 22, 2016)

Luke Cool said:


> So I guess my question to you is not can you, but should you use these important adjustments to tweak the valley?


Not saying you should, just making him aware of my experience in it effecting the valley. If I had the time I could have done several things to the Elite and probably gotten the valley back. I didn't. So I went back to where I started. I took my Chill X down to minimum DW today. 5 turns. Zero noticeable difference in the valley from maxed out at the upper to the lower, other than lighter DW. They asked if anything could add or take away from the valley. Some things seem to do just that. So if you make a change, and the valley changes; it's good info to know what to look for to change back or fix. Would I rely on DW change to change the valley? No. Now that I've seen it will I be more aware of it in the future? Yes.


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## Luke Cool (Oct 16, 2015)

boilerfarmer12 said:


> Changing the DL may affect valley slightly.
> As far as moving the draw stops, uh yea that's what it does. it shortens the valley and essentially the draw which means you will hold of lot more weight. the cams aren't fully rotating.


There are two cams on each cam. The big one is for the string, and the smaller one in for the cables.
Let's look at the bows that are draw length specific. 
The outer cam has a tear drop shape, it's very aggressive, and it does participate in the let-off valley.
On bows with adjustable draw lengths, the outer cam is rounder. This is a compromise because there is no participation in the let-off valley.
Instead, the large outer cam is round and uniformly spaced from the axle throughout the duration of the possible let-off valley and draw stop area.
When draw length is adjusted, the inner cams that guide the cables are rotated into a different positions in respect to the large outer cam.
The position of the small cam determines the draw length, and where the let-off valley and draw stop is. 
This is an example. Not all adjustable bows are exactly like this.
On some, as it gets closer to the end of the draw, the outer cam is not uniformly spaced from the axle.
What I'm saying is, what will work on one bow, may not work on another. 
.


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## bigcountry001 (Jul 5, 2016)

great chart and information


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## Luke Cool (Oct 16, 2015)

bigcountry001 said:


> great chart and information


Thanks.


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