Advanced compound bows feature pulley systems called cams that are found at each end of the bow to pull the strings. As you draw the bow, the cams pull and turn the strings, lessening the amount of force it requires. This makes advanced compound bows easier to use than traditional or recurve bows. Most bows are made up of one riser set in the middle of two limbs, with the cams found at the end of each limb. Risers are usually made from magnesium or aluminum while the limbs may be a combination of fiberglass, laminated wood, plastic, or carbon foam.
Kinds to choose from
Advanced compound bows come in single cam, hybrid cam, twin cam, and binary cam variations. Single cams have two wheels: one round known as the idler wheel and the other elliptical called the power-cam. They are easier to use compared to the other kinds and generate less noise, although they can be hard to tune and may have uneven nocking.
Hybrid cams, on the other hand, use two elliptical cams, one known as the power cam and the other the control cam. They offer straighter nocking so they’re more accurate and are easy to tune and maintain.
As for twin cams, they have two cams for each limb, which may either be elliptical or round depending on the design. Faster and more accurate, they have the most level nocking around, making them ideal for competitive shooting. In the case of binary cams, they are compound bows with two cams for each limb like the twin cams, except that the cams are arranged to have the top and bottom cams moving in relation to one another. Since the cams move independently of the limb, this takes care of problems like varying string lengths and limb deflection.