Good quality compound bows are those utilizing the system of levering cables to bend the limbs. The limbs are the upper and lower part of the bow, which gives the power and flexes to eject the arrow. The limbs of a modern compound bow are stiffer in comparison to the old-fashioned longbows or the re-curve bows. This is because its manufacture does not use wood. the energy efficiency point of view is that wood cannot make a good compound bow as a raw material.
The extra stiffness that the modern compound bows have is due to the pulleys and levers that they have. When these elements are not present, you cannot flex the compound bow. When you pull strings backwards, you gain a mechanical advantage, and a peak weight is reached providing the energy required to eject the arrow.
The ability to be used in any weather is another added advantage of the modern compound bows. It can be hard to use bows made of wood in damp or rainy weather as most woods absorb water. Besides, the traditional cannot be used as well in dry weather as the natural oil tend to evaporate and the wood cracks.
There have always risen arguments that which materials are the best to make good quality compound bows. Others can also argue that which are the specific types of compound bows present in the market. As long as a material can be used in the construction of an aircraft, ranging from aluminum, magnesium or their alloys, they are good for the manufacture of a good compound bow, and that is the solution to all these arguments.
The limbs of a compound bow contain the strength. The pulleys or the cables store no energy. Also important is the construction of the wheels and cams, as they must drive the strings so as to smoothly function. In as much as the term string is being used, the modern compound bows are equipped with a highly efficient polyethylene cable and do not use string. The cables that can hold much tensile strength are made not to stretch, as stretching lowers the cables efficiency. High tensile steel is used in some old-fashioned cables, though the good quality bows incorporate the cables made from polyethylene.
Controlling directly the speed of the arrow are the cams and there exist few different types of bows that have either hard or soft cams. The softer cams are more applicable in compound bows normally being used by the beginners.