The Relationship between Draw Weight and Stabilizer/Bow Weight

QandA logoI love it when I get questions I had never thought about before. When you learn a subject, it tends to channel one’s thoughts, thus avoiding questions that can challenge them, so it is good to consider such questions. The question that stimulated this flood of philosophical thinking was: “If I increase the draw weight of my bow should the weight of the stabilizer also be changed?”

* * *

At first this seemed like one of those questions beginning Olympic Recurve students ask that are inherently nonsensical, but this one is not.

The “stabilizer weight,” including how that weight is distributed, is primarily a matter of balancing the bow as well as resisting movements that can occur in the short amount of time the arrow is on the string and moving (~ 20 ms). (The long rod of a OR setup resists the bow from tilting up and down and twisting left and right, while the short rods resist the bow from rocking left and right or rotating around the axis of the long rod. About the only motion they don’t resist is movement along the axis of the long rod, which is normal and acceptable. Note, though, that the biggest source of movement resistance is the mass of the riser itself.) The draw weight is a matter of force applied to the string and riser by the archer. The weight of the stabilizer and bow is also a force but it is at roughly a right angle to the draw force … and the two do overlap some. (If you didn’t know that weight is a force, you weren’t paying attention in middle school science class.)

The deepest part of the grip of your bow (called the “pivot point”) is typically the midpoint of the length and mass of the bow. Your bow hand is mostly below that point so the bow draw force (created by your two hands and the musculature and skeleton between them) is pulling the bow back into your bow hand but also partly upward, too (like the way a construction crane works (see illustration and photo), the pull of a cable from the bottom causes the top of the other end of the crane to rise, including any weight attached to it). So, like the crane, the draw hand is supplying some of the upward force needed to hold the bow up against gravity. When you raise the draw force, you increase the amount of this effect and it is easier to hold the bow up at full draw, that is the bow “feels” slightly lighter. So, you could add more weight to your bow or take some off if it feels better, but there is no reason to try to compensate for the increased draw weight other than that.

The bridgework bit is like your bow arm. Pull on those cables and the arm will move up. (The draw force is the equivalent of the pull on the cables) And, yes, I know that the cables can also lift what is on the end of the hook without moving the arm, sheesh!

The bridgework bit in this crane is like your bow arm. Pull on those cables and the arm will move up. (The draw force is the equivalent of the pull on the cables.) And, yes, I know that the cables can also lift what is on the end of the hook without moving the arm, sheesh!

There should be no effect of the draw weight change on the feeling of balance at full draw, even though the strain you feel at full draw has gone up. That increase in strain is horizontal, not vertical. So, if your bow still feels nice and balanced, you are good to go.

The bow arm acts like the beam of the derrick, with the draw force being like the force acting through the cables. This produces a slight upward force at the bow hand which helps to hold the bow up.

The bow arm acts like the beam of the derrick, with the draw force being like the force acting through the cables. This produces a slight upward force at the bow hand which helps to hold the bow up.

Realize, though, that since your “back half” takes on part of the work of your “front half” as described above, once you let the string go, then it is harder for the front half (your bow arm specifically) to absorb the loss of help from the draw arm and “dropping your bow arm” after the shot becomes more of an issue. We do not want the bow arm to drop soon after the shot because of “normal variation”—sometimes the drop will occur later (no problem) and sometimes sooner. If the “sooner” instances involve cases in which the arrow is still attached to the string, the dropping bow will take the string and arrow with it and a low shot will occur (definitely a problem). The indicator for the form flaw “dropping your bow arm” is that low arrow hits points show up out of the blue, as we say.

 

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