The difference between compound bows and recurve bows

(I) As we all know, the bow used in recurve archery in modern sports is composed of the main parts such as the bow handle, bow limb, bow string, arrow rest, arrow side pad, sight and counterweight shock absorber. The compound bow is composed of the bow handle, bow arm, eccentric wheel, wheel axle, bow string, rear view window, tension adjustment bolt, cable, cable limit rod, string slide, arrow rest, sight, counterweight shock absorber and release device. Both recurve bows and compound bows are sports equipment that shoot arrows at targets through effective and consistent bow opening by humans with the help of the elastic force of the bow limb. For bows with the same tension standard, the longer the bow of the recurve bow is pulled, the greater the tension is, and the farther the arrow can be shot. The compound bow uses eccentric wheels and fixed pulleys of different shapes installed at the fixed positions of the upper and lower bow pieces (most of the compound bows of the aiming type generally use symmetrical eccentric wheels), fix the positioning length cable and bowstring on the pulley positioning pin and install the bowstring of appropriate length through the pulley groove, so as to use the lever principle of the eccentric wheel to pull the bow with heavier tension. After the bow is pulled, the tension will eventually be reduced by 65-75% according to the different shapes of the eccentric wheel. In other words, the opening force of the compound bow is large, and the symmetrical force of the bow after it is pulled is greatly reduced. It is worth mentioning that the longest draw distance of the compound bow is unchanged by the mutual restraint of the pulley positioning pin and the cable and bowstring. Therefore, for the same bow, after the bow is determined, the tension is consistent, and theoretically the distance of the arrow shot is also equal.

(ii) Different sights are used, and the aiming methods are different. The aiming of a recurve bow is to use the tangency of the bowstring and the bow handle (or the outer ring of the front sight) to ensure the distance between the arrowhead and the eye through the same relationship between the hand that hooks the string and the lower jaw. It can also be said that the aiming method of a recurve bow is formed by the overlap of two triangles at a certain target distance, namely, the vertical (the fixed distance between the arrowhead and the eye is extended and contracted to the target intersection through the straight line of the arrow tip and the front sight) and the horizontal (the straight line of the fixed distance between the bowstring and the front sight is extended to the target intersection). Most compound bows used in competitions use optical sights. Its sight is based on the recurve bow sight, with the front sight replaced by a magnifying glass. To ensure the verticality of the bow push, a horizontal bubble can be installed at the bottom of the magnifying glass; a rear-view window is installed at the eye position above the bowstring and arrowhead. In this way, a three-point one-line relationship is formed between the front sight of the rifle (the aiming point in the middle of the magnifying glass), the notch (the rear-view window on the bowstring) and the target. Looking at the magnifying glass on the sight through the rear-view window forms the optical principle of the telescope, and the target is magnified and clear, which is equivalent to optical aiming. The aiming method of a compound bow is simply to center the line. That is to say, the outer circle of the magnifying glass should be centered when viewed through the rearview window, and the aiming point in the magnifying glass should be aligned with the center of the target.

(III) The arrow rest of the recurve bow generally adopts the side-mounted type. Due to the hand-drawing and releasing of the string, the tail of the arrow after the string is released will swing left and right within a certain distance, and it can only maintain longitudinal straightness after the parabola. Most of the compound bows used in competitions use the straight-shooting type arrow rest. Since the release device is used for mechanical release, the influence of the fingers on the bowstring can be avoided, and the longitudinal flight of the arrow can be guaranteed to be straight.

(IV) The method of releasing the arrow is different. The release of the recurve bow is achieved by the uniform release of the three fingers of the hand that draws the string, so that the bowstring rolls out from the belly of the finger at the point of support. The compound bow is specially made with different types of mechanical release devices, which can shoot the arrow by pulling the trigger on the release device with the thumb or index finger. Simply put, the release of a recurve bow is achieved through the action of three fingers on the bowstring. The change in the force of different fingers will directly change the flight direction of the arrow. For example, if the upper finger (index finger) exerts too much force or releases late, the arrow will be high; if the lower finger (middle finger, ring finger) exerts too much force or releases late, the arrow will be low; when releasing, the force of the curved finger muscles is not smooth or inward, the arrow will be biased to the left; if it is loose or outward, the arrow will be biased to the right. The release device of the compound bow is developed and manufactured to address the inconsistency of human release, which basically solves the problem of the influence of human factors on the equipment. From the release of the recurve bow with three fingers facing the bowstring to the release of the compound bow release device with the point against the bowstring, the accuracy of the shot arrow has been greatly improved.

(V) The vibration of the bow itself will inevitably affect the flight of the arrow. The heavier the tension, the greater the vibration. The shock absorption of the recurve bow relies on the weighted shock-absorbing rod installed on the bow handle and the shock-absorbing rubber block bonded to the upper and lower bow pieces, while the compound bow can also install shock-absorbing rubber blocks on the sight and the bowstring cable limit rod. This makes up for the excessive vibration caused by the large shooting force.

In short, the recurve bow is artificially increasing the symmetrical force on the bow. The fuller the bow is opened, the greater the linear symmetrical force is, and the effective and consistent control ability is relatively weakened. The compound bow is formally aimed at this weakness. Through modern scientific principles, the recurve bow is mechanically modified. The archery technique of the compound bow is easier to master than that of the recurve bow, and it is quick to get started. It can stimulate the interest and confidence of the shooter, and the accuracy is higher than that of the recurve bow. The disadvantage is that it takes more force to open the bow at the beginning. As long as it can be pulled open, it is suitable for all ages, men and women, and it should be considered a good thing from the perspective of physical fitness and muscle strength.