asymmetric limb length in bows
Is there a purpose for asymmetric limb length in Mongol/Hunnic bows other than convenient horseback usage? The Manchus seem to have used large symmetric bows on horseback, so I've wondered whether there's a reason for bow limb asymmetry beyond mounted shooting. (E.g., does it have something to do with ease of tillering?)
Not sure about the reason but assymetry enjoyed a long period.
how about:
if you observe closely, always the lower limb bends more in a symmetric "horsebow" (at least when shot the usual way). This may be balanced by a shorter (=stronger) lower limb.
:?
if you observe closely, always the lower limb bends more in a symmetric "horsebow" (at least when shot the usual way). This may be balanced by a shorter (=stronger) lower limb.
:?
I remember Csaba Grozer telling me that he found asymmetric bows performed better when handled correctly. That is, with the grip tilted forward rather than being held perpendicular to the ground. I don't know why that should be.
Japanese yumi are the most extreme example; but I think their origin may have been to do with the best use of the all wood/bamboo construction without having excessive length below the grip.
Japanese yumi are the most extreme example; but I think their origin may have been to do with the best use of the all wood/bamboo construction without having excessive length below the grip.
I have wondered about this point myself, since I use a modern "Hun-styled" asymmetrical bow. At one point of time, I was looking more for a technical explanation than anecdotal accounts. Eventually, I turn my search by combing through Kyudo sites since the yumi is a well known asymmetrical bow. My rationale was, since Kyudo is so highly codified and technical (to the point of being pedantic, at least to me) there's got to be something written about asymmetrical bow from their perspective.
The closest I found that gives a somewhat technical explanation on the advantages of an asymmetrical bow in English is this link. ( http://eclay.netwiz.net/translat/kyudo.htm ). The article presents several debate on the asymmetrical advantages of the yumi.
Long story short, the asymmetrical bow, provides a more stable/stronger grip (in you hold the bow in the kyudo style) when the bow is tilted forward at an angle (like when you hold a handgun) as opposed to holding the bow 90 degree vertically from the ground. There are some line diagrams in the article that try to illustrate the point.
I'm not too sure if the purposed bow mechanic applies specifically to the Yumi, since compared to other bows, the yumi asymmetrical profile is considered pretty extreme.
The closest I found that gives a somewhat technical explanation on the advantages of an asymmetrical bow in English is this link. ( http://eclay.netwiz.net/translat/kyudo.htm ). The article presents several debate on the asymmetrical advantages of the yumi.
Long story short, the asymmetrical bow, provides a more stable/stronger grip (in you hold the bow in the kyudo style) when the bow is tilted forward at an angle (like when you hold a handgun) as opposed to holding the bow 90 degree vertically from the ground. There are some line diagrams in the article that try to illustrate the point.
I'm not too sure if the purposed bow mechanic applies specifically to the Yumi, since compared to other bows, the yumi asymmetrical profile is considered pretty extreme.
There are some problems in that article about the mechanics of holding the grip of a symmetrical bow or at least one that has a vertical handle area.
In non-Japanese archery there are many ways of holding a bow and the method of transmitting pressure from the hand to the bow. For example, the Korean method of applying pressure from the base of the palm produces a straight line from the arm to the bow. One of the Near Eastern methods, in contrast, concentrates pressure on the belly of the bow through the area at the base of the index fingers and thumb with the wrist turned down so that the pressure is again concentrated on a line straight along the arm.
Some of the current reconstructions of asymmetrical composite bows also have rounded handles reminiscent of Scythian bows that are rarely present in the original archaeological samples they are based on. This means the dynamics of the grasp are different and it may lead to slightly different performance. Since the Scythian bows were asymmetrical, this does not mean the experience in shooting these bows is not similar to ancient bows, but they are a hybrid design.
Has anyone thought that asymmetrical composite bows might have been designed that way to make bracing more consistent? I have found that one of the problems bracing horn bows was the adjustments necessary to have both limbs bend and equal and even amount. Admittedly, it only takes a few seconds to fix a curvature issue. Since most of the time these bows were popular, bow cases for strung bows were not used, I doubt putting them in the bow case was a design criterion.
In non-Japanese archery there are many ways of holding a bow and the method of transmitting pressure from the hand to the bow. For example, the Korean method of applying pressure from the base of the palm produces a straight line from the arm to the bow. One of the Near Eastern methods, in contrast, concentrates pressure on the belly of the bow through the area at the base of the index fingers and thumb with the wrist turned down so that the pressure is again concentrated on a line straight along the arm.
Some of the current reconstructions of asymmetrical composite bows also have rounded handles reminiscent of Scythian bows that are rarely present in the original archaeological samples they are based on. This means the dynamics of the grasp are different and it may lead to slightly different performance. Since the Scythian bows were asymmetrical, this does not mean the experience in shooting these bows is not similar to ancient bows, but they are a hybrid design.
Has anyone thought that asymmetrical composite bows might have been designed that way to make bracing more consistent? I have found that one of the problems bracing horn bows was the adjustments necessary to have both limbs bend and equal and even amount. Admittedly, it only takes a few seconds to fix a curvature issue. Since most of the time these bows were popular, bow cases for strung bows were not used, I doubt putting them in the bow case was a design criterion.
I think the only way to hold a bow entirely symmetrically is to hold it with feet and draw with both hands. Otherwise there is at least some kind of asymmetry.
When you say asymmetry do you mean asymmetry as Yumi or asymmetry as english long bow ?
At lest one reason is that if bow does not have pistol grip, the hand can be positioned in better angle.
AFAIK no known historical bow has pistol grip. (Correct me if I am wrong ... )
When you say asymmetry do you mean asymmetry as Yumi or asymmetry as english long bow ?
At lest one reason is that if bow does not have pistol grip, the hand can be positioned in better angle.
AFAIK no known historical bow has pistol grip. (Correct me if I am wrong ... )
I have made and shot some very asymmetrical bows. Imagine taking a #40 long bow upper limb and putting a #40 short bow limb on the bottom. When at brace there is balance. Both limbs draw quite differently but return to balance at brace. This is the approximate launch place of the arrow. The aim seems correct, only the feel of the draw is different.
So, I find little enough difference to a center shot bow or any other. Possibly there is some subtle difference in string harmonics which I am missing.
This also goes for a crossbow with lifted arms. The bow, however asymmetrically drawn (to the centerline of the bow) returns to a balanced place and the shot is predictable.
So, I find little enough difference to a center shot bow or any other. Possibly there is some subtle difference in string harmonics which I am missing.
This also goes for a crossbow with lifted arms. The bow, however asymmetrically drawn (to the centerline of the bow) returns to a balanced place and the shot is predictable.