Bow shape

This shape, viewing the limbs, is designed to take into account the construction materials, the performance required, and the intended use of the bow.

Longbows as used by English archers in the Middle Ages at such battles as Crecy and Agincourt were straight limb bows.

Recurve bows made out of composite materials were used by, among other groups, the Persians, Parthians, Scythians, Hyksos, Magyars, Bulgars, Huns, Turks, Mongols, and Chinese.

However, as the bow is drawn, the recurve 'unwinds', the limb becomes effectively longer, and the mechanical advantage of the archer increases.

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.

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.

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 and with heavy draw weights, used en masse.

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.

This allows a bow that is significantly shorter than a recurve or a longbow to shoot with the same or greater velocity and power.

They became the classic weapon of the horse archers who have repeatedly conquered much of Asia and Europe; their short profile compared with longer bows made them ideal for horseback use.

Highly reflexed composite bows are still used in Korea and were common in Turkish and Indian traditional archery.

Shapes may be optimized for various purposes, especially maximum speed of the arrow; the details are the subject of active research.

"Eiffel Tower" bows taper sharply, but smoothly, to a very narrow outer tip.

Current definitions of the traditional longbow require approximations of a D-shaped cross section.