Bow shape There are many different kinds of bow shapes . However , most fall into three main categories : straight , recurve and compound . Straight and recurve are considered traditional bows . In archery , the shape of the bow is usually taken to be the view from the side . It is the product of the complex relationship of material stresses , designed by a bowyer . This shape , viewing the limbs , is designed to take into account the construction materials , the performance required , and the intended use of the bow . If a limb is ' straight ' its effective length remains the same as the bow is drawn . That is , the string goes directly to the nock in the strung ( braced ) position . The materials must withstand these stresses , store the energy , and rapidly give back that energy efficiently . Many bows , especially traditional self bow s , are made approximately straight in side - view profile . Longbows as used by English Archers in the Middle Ages at such battles as Crecy and Agincourt were straight limb bows . A recurve bow has tips that curve away from the archer when the bow is strung . By definition , the difference between recurve and other bows is that the string touches a section of the limb when the bow is strung . Recurve bows made out of composite materials were used by , among other groups , the Scythians , Hyksos , Magyars , Hun s , Turks , Mongols , and Chinese . The unqualified phrase " recurve bow " or just " a recurve " in modern archery circles usually refers to a typical modern recurve bow , as used by archers in the Olympics and many other competitive events . A reflex bow is a bow that has curved or curled arms which turn away from the archer throughout their length . Design factors . If a limb is ' straight ' its effective length remains the same as the bow is drawn . That is , the string goes directly to the nock in the strung ( braced ) position . When the limb is recurved ( tip of limb away from the archer ) , the string touches the limb before it gets to the nock . The effective length of the limb , as the draw commences , is therefore shorter . However , as the bow is drawn , the recurve ' unwinds ' , the limb becomes effectively longer , and the mechanical advantage of the archer increases . Counter to this , stresses are building up in the materials of the limbs . The belly of the bow ( nearest the archer ) is in compression , the back ( furthest away from the archer ) is in tension , and the line between is in shear . The materials must withstand these stresses , store the energy , and rapidly give back that energy efficiently . The amount of energy stored is determined by the stresses withstood and the shape of the limb , from the unstrung position to strung ( consider as pre - stressed ) , then de - formed further to full draw as the recurve unwinds . These basic principles of changing mechanical advantage , to efficiently store more energy , and deliver it to accelerate the arrow , were clearly understood in antiquity , as shown by the examples that follow . Straight bow . Many bows , especially traditional self bow s , are made approximately straight in side - view profile . They are generally referred to as straight , despite the minor curves of natural wood and the " set " or curvature that a wooden bow takes after use . When the archer commences the draw , mechanical advantage is at its greatest and the bow limbs are only pre - stressed to the strung position ; therefore drawing weight is at a minimum . However , the drawing weight rapidly increases because mechanical advantage reduces ( consider the string is pulling more and more directly on the limbs ) and stresses are building up in the limbs . Consequently , drawing weight ' stacks ' ( very rapidly increases ) . On release , the reverse happens , the arrow is accelerated by maximum force , and this force rapidly decreases . Hence , the arrow must be sturdy enough to withstand such acceleration and , as the string may decelerate , it is possible for the arrow to leave the string prematurely , which is inefficient . Historical and current use . Longbows as used by English Archers in the Middle Ages at such battles as Crecy and Agincourt were straight limb bows . Usually made of yew , these bows were used to great effect by many archers shooting together in massed volleys . The arrows were long and heavy ( ' clothyard shafts ' ) with armour piercing ' bodkin ' heads . Practice for such long range warfare survives today in a Clout shoot , named after a type of shirt . Bows with curved side - view profiles . Recurve bow . A recurve bow has tips that curve away from the archer when the bow is strung . By definition , the difference between recurve and other bows is that the string touches a section of the limb when the bow is strung . A recurve bow stores more energy and delivers energy more efficiently than an equivalent straight - limbed bow , giving a greater amount of energy and speed to the arrow . A recurve will permit a shorter bow than the simple straight limb bow for a given arrow energy and this form was often preferred by archers in environments where long weapons could be cumbersome , such as in brush and forest terrain , or while on horseback . Recurved limbs also put greater strain on the materials used to make the bow , and they may make more noise with the shot . Extreme recurves make the bow unstable when being strung . An unstrung recurve bow can have a confusing shape and many Native American weapons , when separated from their original owners and cultures , were incorrectly strung backwards and destroyed when attempts were made to shoot them . Historical and current use . Recurve bows made out of composite materials were used by , among other groups , the Scythians , Hyksos , Magyars , Hun s , Greeks , Turks , Mongols , and Chinese . The recurve bow spread to Egypt and much of Asia in the second millennium BC . Presumably Greek and Phoenician influence would have introduced the recurve form to the rest of the Mediterranean region . The standard weapon of Roman imperial archers was a composite recurve , and the stiffening laths ( also called siyah in Arabic / Asian bows and " szarv " ( horns ) in Hungarian bows ) used to form the actual recurved ends have been found on Roman sites throughout the Empire , as far north as Bar Hill on the Antonine Wall in Scotland . During the Middle Ages composite recurve bows were used in the drier European countries ; the all - wooden straight longbow was the normal form in wetter areas . Recurve bows depicted in the British Isles ( see illustrations in " The Great War Bow " ) may have been composite weapons , or wooden bows with ends recurved by heat and force , or simply artistic licence . Many North American bows were recurved , especially West Coast bows . Recurve bows went out of widespread use , for war , with the availability of effective firearms . Self bow s , composite bow s , and laminated bow s using the recurve form are still made and used by bowyers and amateur and professional archers . The modern recurve bow . The unqualified phrase " recurve bow " or just " a recurve " in modern archery circles usually refers to a typical modern recurve bow , as used by archers in the Olympics and many other competitive events . It employs advanced technologies and materials . The limbs are usually made from multiple layers of fiberglass , carbon and / or wood on a core of carbon foam or wood . The riser ( the centre section of the bow ) is generally separate and is constructed from wood , carbon , aluminium alloy or magnesium alloy . The term ' riser ' is used because , in a one - piece bow , the centre section rises from the limbs in a taper to spread the stress . Several manufacturers produce risers made of carbon fibre ( with metal fittings ) or aluminium with carbon fibre . Risers for beginners are usually made of wood or plastic . The synthetic materials allow economic , predictable manufacture for consistent performance . The greater mass of a modern bow is in itself an aid to stability , and therefore to accuracy . It should be remembered , however , that accuracy is also related to a bow ' s draw weight , as well as how well an archer handles it . It ' s therefore imperative , particularly for beginner archers , to never overestimate their capabilities , and to choose a draw weight that is appropriate for their body build and level of experience . The modern recurve is the only form of bow permitted in the Olympics ( though the Compound bow is permitted in some categories at the Paralympic Games ) and is the most widely used by European and Asian sporting archers . The modern Olympic - style recurve is a development of the American Flatbow , with rectangular - section limbs that taper towards the limb tips . Most recurves today are " take - down " bows — that is , the limbs can be detached from the riser for ease of transportation and storage , and for interchangeability . Older recurves and some modern hunting recurves are one - piece bows . Hunters often prefer one - piece bows over take - down bows because the limb pockets on take - down bows can be a source of noise while drawing . Other equipment . Archers often have many other pieces of equipment attached to their recurve bows , such as : Reflex bow . A reflex bow is a bow that has curved or curled arms which turn away from the archer throughout their length . When unstrung , the entire length of the bow curves forward from the belly ( away from the archer ) , resembling a " C " ; this differentiates a reflex bow from a recurve bow in which only the outer parts of the limbs turn away from the archer . The curves put the materials of the bow under greater stress , allowing a fairly short bow to have a high draw weight and a long draw length . This allows a bow that is 1 : 2 the length of a recurve or 1 : 3 the length of a longbow to fire at the same or greater velocity and stopping power . The materials and workmanship must be of high quality . Highly - reflexed bows are more difficult to string and may reverse themselves suddenly ; they have seldom been used for hunting . However , they were the main armament of the Mongol armies that conquered much of Asia and Europe ; their short profile compared to longer bows made them ideal for horseback use . History . Bows of traditional materials with significant reflex are almost all composite bow s , made of the classic three layers of horn , wood , and sinew ; they are a variant of the recurve form normally used for such bows . Highly reflexed composite bows are still used in Korea and were common in Turkish and Indian traditional archery . There is an interesting section in Homer ' s Odyssey when the suitors attempt to string Odysseus ' bow and are unable to do so , whereas Odysseus is able to string it " without standing up " . A reflex bow is almost impossible to string unless one knows the technique and is easiest to string from a sitting position . This passage has been suggested as evidence that reflex bows were just beginning to spread into the Aegean area at the time of writing . Decurve bow . A decurve bow is a bow that has arms curved or curled at the ends to turn towards the archer . This bow form reduces the strain on the bow when it is used , and the bow may be under no tension at all when strung , so that it can be kept ready for immediate use at all times . It also reduces the energy stored in the bow , and the speed of the arrow . The form is seldom used in modern or historical bows , but was occasionally used by groups such as the Mohave who did not have easy access to good quality bow wood . It allowed them to make effective hunting weapons from the poor - quality material available . Deflex bow . A deflex bow is a bow that has arms curved or curled at the base , to turn towards the archer when unstrung . This bow form reduces the strain on the limbs and also the energy stored by the weapon . Most modern recurve bows are built with some degree of deflex . It has been used occasionally in traditional bows , for example to make a bow that looks like a traditional hornbow without using any actual horn . Compound bow . The compound bow , not to be confused with a composite bow , is a modern bow that uses a levering system , usually of cables and pulleys , to bend the limbs . The limbs of a compound bow are much stiffer than those of a recurve bow or longbow . This limb stiffness makes the compound bow more energy - efficient than other bows , in conjunction with the pulley / cams . The typical compound bow has its string applied to pulleys ( cams ) , and one or both of the pulleys have one or more cables attached to the opposite limb . When the string is drawn back , the string causes the pulleys to turn . When the draw commences , the archer has reduced mechanical advantage , but during the draw , as the pulley cams rotate , and the archer gains mechanical advantage over the bending limbs , more energy is stored , in comparison to other bows . Outline in frontal view . Bows usually taper from the handle to the tips . Tapering reduces mass in the outer limb and dissipates the limb stresses ; this increases the speed at which the tips move which propels arrows faster . Shapes may be optimized for various purposes , especially maximum speed of the arrow ; the details are the subject of active research . Narrow bows normally taper uniformly . However , the taper of flatbows varies . The working limbs of " paddle " bows maintain width for almost the entire limb length , " pyramid " bows taper uniformly from the handle to a narrow tip , and " Holmegaard - style " bows remain full width to about two - thirds of the way along the limb , then narrow sharply . " Eiffel Tower " bows taper sharply , but smoothly , to a very narrow outer tip . Cross - section of limbs . The optimal cross - section of the bending section of a bow limb is rectangular , and almost all modern bows have such limbs . However , many , perhaps most , traditional bows have had a cross - section closer to circular , with every possible variation being used at some point . Current definitions of the traditional longbow require approximations of a D - shaped cross section .