THE SPORT
BOW TYPES:
To learn more about the most used types of bows, select from the list on the side
THE RUDIMENTARY BOW
For a long time man sought to improve both bows and arrows in terms of accuracy.
The first bows were basically obtained by bending a wooden stick and tying a string to the ends. Flexible and fibrous woods were used for this purpose.
And so it was until the medieval era where English and French archers fought using Longbows. This type of bow had a wingspan almost the size of the archer himself.
Arrows were made from wooden or bamboo sticks to which molten metal tips and feathers from the wings of birds such as turkeys or gooses were added to the back of the arrow to give stability to the flight.
But the search for faster bows continued and the application of composite materials such as horns, resins and other woods were used.
THE RECURVE BOW
It was discovered that by bending a bow in the opposite direction to its curvature, greater strength could be obtained to draw the bow and still add speed to the arrow. Then came the recurve bow.
This type of bow was used by archers in competitions until the 30s when the first detachable bows appeared. This would make it easier to transport the equipment in smaller cases and even replace the limbs (the part responsible for the effort and application of power to the string) with stronger ones.
The person responsible for manufacturing the first bows of this type was Mr. Earl Hoyt. Called TD1 (Take Down 1), it was made with a cast magnesium handle and wooden limbs.
Since then, manufacturers have started to invest in modern materials such as aluminum alloys, carbon fibers and foams, and even ceramics.
Nowadays the vast majority of competition bows are made of aluminum and carbon fiber. They use curved limbs, attached to the grips through standardized fittings so that limbs from one manufacturer can be used in grips from another manufacturer.
This allows for a wide range of bow configurations to suit all sizes and draw strengths.
Competition recurve bows
Competition curved blades
THE COMPOUND BOW
Since the 1960s, researchers have sought to develop more powerful and compact bows. That's when the compound bow came about.
It basically used a handle like the recurve bow, but with shorter blades and had pulleys attached to the end of each limb. From these pulleys, steel cables run to the opposite end of the bow so that when the string is pulled, these cables wrap around the pulleys and help reduce the force used to draw the bow.
Several models of compound bows have appeared since then, including quite extravagant bows that used up to six pulleys. Others had a recurve bow appearance and their pulleys were located next to the grip.
But one thing was certain. The compound bow conquered its adherents and is now considered the deadliest of melee weapons and also the most accurate spring-action projectile launcher.
Cables and string are attached to the pulleys to lessen the force exerted by the archer
Pulleys can be manufactured in different shapes
Modern Compound Bows.
On the left a competition bow. On the right, fully equipped hunting bow.
Force graphs on different types of pulleys
During the draw of the string, the effort required to open a compound bow can be translated into a graph like the one shown above. In this it can be noticed different curves of effort for each type of pulleys available in the market.
At the beginning of the pull, a sudden increase in power is noticed. Power is maintained at full power for most of the pull, which is called "peak wheight". At the end of the pull, the power drops sharply. This part of the graph is called the "pull valley", where the power reduction can reach up to 80% of the "peak wheight", depending on the shape of the pulleys.
Also due to the shape of the pulleys, it is impossible to pull the bowstring beyond the "pull valley".