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The fundamental principal behind the bow is simple. As the bow is drawn the limbs bend and store energy. When the string is released, energy stored in the limbs is imparted to the arrow as the limbs return to their "at rest" position. Any energy not absorbed by the arrow is dissipated as noise and vibration in the bow. Bow Efficiency is the measure of how completely a bow transfers energy to the arrow. Efficiency is measured in percent (%). Cast is how efficiently a bow shoots an arrow or how far in yards. Weight is how much pulling force in pounds it takes to draw the bow back to anchor point at one's draw length (longbows and recurves are usually measured at 28" draw length). Speed measured in Feet Per Second (FPS) has become an important measurement for bows in recent years. Bowhunters are always interested in Kinetic Energy, measured in Foot Pounds as an indicator of how hard an arrow hits or its penetration power.
Bows can be divided into two simple categories, bows without wheels (longbows and recurve bows) and bows with wheels (compound bows). Until the late 1960's into the early 1970's when compound bows came into vogue, the only choice archers had was either a longbow or a recurve.
The longbow has been around the longest and is the simplest bow. The oldest longbow design, the self-bow, is made from one piece of wood and is basically straight. When braced (strung-up) the bow forms a semi-circular arc from one limb tip to the opposite limb tip. This design doesn't have well defined riser section and the handle forms part of the curve of the bow. For this reason, self-bows tend to give a "kick" or recoil to the bow hand when an arrow is loosed (released). To alleviate bow hand shock in later designs, the handle was made thicker and the limbs were now slanted outward toward the back of the bow (away from the archer). This design is known as a reflex bow. Bow designs where the limbs slant inward (toward the archer) are called deflex bows. Reflex bows tend to shoot a little faster than deflex bows and longer bows tend to shoot a little smoother than shorter ones. Reflex vs. deflex and long vs. short shooting characteristics tend to hold true across all types of bows.
Modern technology carried the reflex longbow design one step further and created the recurve bow. Not just slanting straight limbs outward, the modern recurve has an outward curve to the limbs. Combine this with laminated limbs of wood and fiberglass, and a cutout in the riser section allowing the bow to be shot closer to "center-shot (arrow is more in line with thrust of the string) and the recurve bow draws smoother, has better cast, transmits little or no shock to the bow hand, and is less affected by temperature and humidity extremes. Recurve bows are also available in "take down" models, which come apart for easier packing into remote areas.
The most recent improvement in bow design has been the compound bow. Compound bows have an eccentric wheel at the end of each limb and two cables running between them. Early designs had four wheels with two of them being idlers. Many had brackets to hold the wheels on the limbs. Today's bows all have the wheels slotted into the limbs. Compounds are popular for two important reasons. Where a recurve gets harder to pull (stacks) as you draw it further back, the compound bow reaches peak weight about half way through the draw then "lets off" or gets easier to pull toward the end and has a reduced holding weight at full draw. For this reason, compound bows can be held at full draw longer for a steadier aim. Also, because of the let-off, the peak weight of the bow is not immediately transferred to the arrow. Therefore lighter arrows may be used yielding a flatter trajectory. Bow let-off and lighter arrows potentially increases accuracy both at known and at unknown distances making compound bows are the overwhelming choice of beginner as well as experienced archers.
If you pick up a bow and hold it like you were about to shoot it, you would be holding it by the grip or handle. Handles are found on both recurve and compound bows. They are usually made of plastic or wood. Some bows have the grip machined as part of the riser. Different types of grips are available producing either a high, medium, or low wrist position. Grips are chosen to suit the shooting style of the archer.
The riser is the middle part of the bow where the grip is located and the limbs are attached. The riser is where most of the equipment is attached to the bow: limbs, sight, arrow rest, stabilizer, etc. Different risers effect how the bow performs. There are straight risers which the have some best features of the other two types; either a deflex riser (is bent out away from the string and is a more forgiving design), or a reflex riser (bent in towards the string placing the arrow closer to the string for more stored energy, thus more speed).
A bow is not a bow without its limbs, which are the longest pieces of the bow. They bend with the draw and store energy. They produce the power to propel an arrow. The limbs attach at he two ends of the riser. Limbs may be all one material as in the case of many longbows and some recurves or they may be laminated. Bow laminations (lams)may be different types of wood, a combination of wood and fiberglass, or carbon. Modern materials like carbon or carbon foam are more stable than traditional wood limbs thus allowing greater consistency and greater accuracy.
Strings are connected to the limb tips in the case of traditional bows and are connected to teardrops at the ends of the cables or directly to the cams of a compound bow. They are usually made of twisted strands of Kevlar, Dacron, or more advanced materials like Fast Flight or blended like Dyneema and Vectran to make a single cord. Dacron is inexpensive, but prone to creep, meaning that it may stretch and make for inconsistent shots. More recent developments in string materials and construction make for less stretch and longer life. Strings have a serving or overwrap in the area where it connects to the limbs or cams and in the areas where the arrow attaches for protection from fraying and strand breakage. String life is greatly extended when it is waxed regularly with a quality string wax.
This is where the arrow sits (rests) as the bow is drawn and shot. Rests are located in the center or the riser section above the hand and below the sight in the sight window area (a cut out section of the riser allowing the arrow to clear the bow without hitting any part of the riser. The longbow has no rest beside the hand. Other bows use plastic or metal rests, while some more bows may be fitted with a magnetic, drop-away, or similar complex rest. More complex rests collapse as soon as the arrow is released to prevent it from hitting the rest which could knock the arrow off course.
The plunger button (often referred to as a Berger button after its inventor Vic Berger) is a device that, when the arrow is being shot, provides side support and cushioning. It also aligns the arrow in the center of the bow and keeps it from hitting the riser once shot. Since the arrow will flex (bend) side to side when released, the cushion plunger provides the necessary resistence to keep the arrow going straight. This accessory is most often used when the string is released with the fingers. Archers usin mechanical release aids usually don't require a plunger since the release is in a straight forward motion. Finger shooters on the other hand experience what is called archer's paradox. The paradox occurs as the strings goes around the fingers as they release the string.
The nocking point is usually either be a piece of string (waxed dental floss is excellent) or a metal (brass) clip attached to the bowstring that holds the arrow nock in a fixed place on the bowstring, keeping it from sliding up and down. More importantly, it serves as an index so the arrow is shot from the same point on the string each time which improves accuracy. Several archers using mechanical releases will also use a "D-loop". a D-loop is a loop of cord or string material forming the shape of a "D" around the nocking point and where the release is attached. This gives a more even release as the pulling and subsequent releasing of the arrow is from straight behind the nock position. It also helps to keep the nock on the string better. Many modern compounds are so short that a very acute angle is formed when the bow is draw with a release. This acute angle may cause the nock to slip off the string before being loosed causing a dry-fire condition.
The sight can come in many forms with a lot of variations. The simplest is a fixed pin sight which has one or more sight pins each set a different distance; i.e. 20 yds, 30 yds, 40 yds. This type of sight lends itself well to hunting situations and field ranges where the distances vary and shots may be unpredictable. Another variation on this theme is a single fixed pin, movable sight where the sight is adjusted each time for a different distance. This gives greater precision in aiming over having to shoot a gap between two pins if the distance is different than the pin setting.Pins may be of straight stock with a head at the end or a circle with a cross-hairs or pin at its center. Other types are scope sights which have some amount of magnification and a dot or circle in the center. Some sights incorporate a level which tells the archer if his or her bow is canted (tilted).
Sight shooting is improved with the aid of a kisser. A kisser button is fixed onto the string and rests at the corner of the mouth when the string is pulled back. This is used as a marking point to let the archer know he or she has pulled the string to the same position. They are usually in the shape of a button, hence the name and are served into position once the correct position is located.
A peep sight is similar to a kisser in that it improves sight shooting and is served into the string. It is attached to the string at eye level and serves as a sort of rear sight. Different sizes and styles are available depending the need. Some have large openings and are good in low light like when hunting or shooting outdoors during overcast conditions. Some have very small openings often equipped with a clarifier (magnification) which is necessary when shooting some scopes. Just as the appeture (opening) varies in size, it may also vary in shape with some being round or oval, others may be cross shaped or segmented.
A stabilizer is a weighted rod that attached to the riser below the grip. It provides balance and dampening. Ideally it tilts the bow foreword slightly once the shot has been made. Newer styles of stabilizers have built-in vibration dampening devices. Hunting bows will require a shorter stabilizer for ease of use in a tree or wooded area. Target archers can get away with a longer model which provides better balance. V-Bars may also be used. V-bars provide lateral stabilization and are mounted at an angle that forms a "V" parallel to the ground (or nearly so). They attach to a straight stabilizer and may be used singularly or in pairs in combination with straight stabilizers for maximun stability.
The sling allows the bow to rest in the archer’s hand without having to actually hold the bow. It prevents the bow from jumping out of the hand when the arrow is loosed. This allows a relaxed grip and more accurate shooting as well as increased confidence.
A clicker tells the archer when he or she has pulled the bow to a predetermined distance. This helps the archer know when the string is pulled back far enough to fire, as too far or too short a pull will produce inconsistent shots. Clickers attach either to the sight window or to the sight bar. They are made od a a steel rod or piece od spring steel and are placed on top of the arrow as it is draw. Adjusted to rest right at the end of the arrow, slight pulling causes it to slap or click against the riser or side plate. At the sound the archer releases the arrow having reached the maximum draw. Clickers are used frequently on target model recurves and some compounds. There are models available that attach to the top limb tip for longbows too.
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This page Copyright © 1999/2007 Michael A. Tichenor & DRB, Inc.
Last Revised: Friday, March 23, 2007