Bow Strings – Bow strings must be replaced when they show signs of wear or weakening. Choosing the best bow strings is made more difficult by the number of materials available. Material for modern bow strings do not stretch, and the shock will damage some bows. The main factor in choosing the correct bow strings is the kind of bow you are shooting.
Longbow: The best bow strings for a traditional longbow provide a degree of elasticity and dampening. Traditional materials used to build longbows are not typically able to take the shock of modern strings materials. When a bow is bent it stores energy that is released into the arrow. When the arrow leaves the bow, the bow string stops the limbs very abruptly. Modern fibers made of high modulus polyethelene like Dyneema or Vectran do not absorb any of this impact and can actually break your bow. If you are shooting a custom longbow or having one built, be sure to discuss the bow strings material with your bowyer. Dacron is the choice of most traditional shooters, and it is usually the best choice for longbows as it is sufficiently strong, yet has a degree of stretch that protects your bow from damage.
Recurves Bow: Bow strings for a recurve are usually designated by the manufacturer or bowyer. High-end competition recurve bows use synthetic materials that withstand the shock of modern bow strings material. However, if you use these high performance bow strings on older bows, the shock can crack limbs and shatter limb tips. Replace your bow strings with the same kind you are using, and if in doubt, use Dacron. If you are having a bow made, and you want the option of using fast, no-stretch modern strings, ask your bowyer about designing reinforced limb tips that can handle it.
Compound Bows: Compound bows use modern construction techniques and materials that allow the use of extremely strong synthetic bow strings. In addition to the mechanical leverage provided by cams, inelastic bow strings transfer all available energy into the arrow, which accounts for significantly increases in arrow speed. Compound bows are not unstrung for storage. Fastflite string will not change point of aim or lose tension over time. Dacron string is a poor choice in a compound bow because it stretches and creeps over time changing the shooting dynamics of the bow. In the case of the compound bow, the best are small diameter, strong and inelastic.
Knowing your bow will give you a better shot at making the right choice in selecting your bow strings.