By: Nick Jedlicka
Okay, count me as one of the guilty! I was not always totally up to speed on what the various parts and functions of my compound bow were. Maybe this was not such a big deal. For a beginner, it may not be essential to know every tidbit of info – but it certainly doesn’t hurt! But, if you’re serious about your bow, target shooting, and hunting, you literally cannot afford to keep yourself in the dark when it comes to knowing the parts that make up a compound bow!
What I am going to try and do is shed some light on the parts of a compound bow and some of the functions of those various parts. Hopefully you are able to pick up some new info that will be helpful to your shooting, or if the compound bow is a totally new or foreign concept to you – you’ll be able to pick up some great info to get started!
Axle to axle – a simple measurement from the top wheel/cam axle to the bottom wheel/cam axle; is the traditional length measurement for a compound bow. The right length is totally a personal preference, longer bows tend to be more forgiving (do not lose a lot of accuracy due to external circumstances), shorter bows are lighter and easier to tote into tight cover and move easier when in a treestand.
Riser – the central part on a compound bow, where the arrow shelf, sight window, stabilizer, string guides, and other accessories are attached. The grip or handle of the bow is also positioned on the riser. Risers are made out of aluminum or composite materials and create the backbone of a bow.
Cam – an oblong rounded component that holds the bowstring and allows the string to be pulled back. The bowstring fits in a narrow track on the cam. A cam can be located on the bottom and top axle, or a bow may have a cam on one end (bottom) and a wheel on the other. Bows today come in a variety of cam configurations such as a single cam, dual cam, and binary cam.
Grip – Located just below the arrow shelf and is where you would hold the bow with your non-dominant hand. Proper hand to grip fundamentals is crucial to consistent arrow flight. If your arrows are flying straight but veer off to the left or right check your grip first for hand torque.
Idler Wheel – similar to a cam, only circular in shape, like a cam the bowstring fits in a narrow track on the wheel. A wheel allows the string to be pulled by the archer to shoot an arrow. A bow that utilizes a wheel/cam design is typically thought of as more reliable as it pertains to consistent releases as the timing of the wheel and cam is all but impossible to disrupt.
Limbs – limbs are connected to the riser and extend towards the bottom and top of the bow and provide support for the axles. Limbs bend and flex when the bowstring is pulled, they are built to withstand pressure and torque when the bow shoots an arrow. Kinetic energy is stored in the limbs and this energy is transferred to the string when the shooter releases it. Limb on today’s bows can either be split or solid in design.
Brace height – the brace height is a measurement from the bow’s handle to the string and is determined by the riser’s design. Typically a longer brace height is desirable, allowing the arrow more time to stabilize a flight path before actually leaving the bow. However, with a longer brace height the slower the arrow speed. A good range of brace height to look for is somewhere in the seven to eight inch range
Release – a mechanical device that allows the string to be held in one small area and released smoothly at each shot. Typically, a release is strapped onto the shooter’s hand or wrist and utilizes a caliper-style grip to hold onto the bowstring or a small release loop/string connected to the bowstring. Releases increase accuracy dramatically.
Bow String – The bowstring is used to transfer energy from the shooters arms and back muscles directly to the limbs of the bow. This allows the bow to be “drawn” and thus store energy. A bow string also is the catalyst to transfer that energy from the limbs to the arrow. On a two cam system the string attaches to both cams, whereas on a “solo” cam system the string ends attach to the cam only, with the string traveling around the top idler wheel
Cables – Cables attach to the bowstring and basically work with the cams during the draw process and the release of the bow string.
Serving – The thread, or monofilament, wrapped area in the midsection of the string that accepts the nock set. Used to protect the actual bowstring from continuous use when the arrow is nocked. Serving can also be used on other parts of the string that can continual wear.
D-Loop – A loop that is used in conjunction with a mechanical release to fire an arrow. D-loops aide in giving better accuracy and more control while drawing and releasing arrows. A down side of a D-loop is that you will loose some speed, but not enough to deter you away from using this essential piece of equipment.
Cable Guard – The rod on compound bows that keeps the cables away from the center of the bow so the arrow can pass by without hitting the cables.
Cable Slide – Fits on the cable guard and helps the cables move smoothly across the cable guard.
Roller Guard– Similar to a cable guard, the cable roller or roller guard is found in many newer bows on the market today. It is stationary in nature and contains both the string and cables and keeps them out of the line of fire by using rollers.
String Suppressor – the string suppressor is designed to stop the string in the original resting position once released to reduce vibration and improve accuracy.
Limb Dampener – Limb dampeners are designed to reduce the vibration of the limbs during the shot.
Sight Window – The cut out section of the bow located on the riser just above the grip. Its purpose is to house the archer’s sight.
Arrow Shelf – the arrow shelf is the horizontal shelf designed into the riser that contains the arrow in all stages of the shot. This is where any type of arrow release is housed. It also protects the gripping hand from accidental injury.
Nocking Point – Is the location of the bowstring where the arrow attaches to the bow.
Stabilizer – is placed on a bow for the purpose of reducing torque and shock after releasing the arrow. In addition a stabilizer acts as a counter balance to help hold the bow steady before releasing an arrow.
Draw Length – When drawing back the string of a compound bow it is only possible to take it back to a certain length before it stops. This point is the full-draw position and the distance at which it can be taken back is called the draw length. The bow can only be shot for the draw length for which it has been set up although it is possible to alter the draw length by modifying the setup of the bow. It is important you are shooting a bow that matches your actual draw length to have consistent accuracy. To find your draw length the simplest way is to measure your wingspan and divide by 2.5. For example if you have a 70-inch wingspan your draw length would be 28”. Therefore you would want a bow that meets your 28” draw length requirement. As stated above most bows today are now manufactured with draw lengths that can be modified.
Draw Weight – The amount of force in pounds required to draw the bow. It is advised to get a bow that you can comfortably pull back. While higher draw weights mean more speed you still need to be able to pull your bow back over and over again without a struggle to aide in correct fundamentals and consistent arrow groupings.
Let off – the percentage of the bow’s draw weight that is required to hold the bow at full draw. For example a bow set at 60lbs, with 80% let-off, will only require that the shooter to hold back 12lbs of weight when the bow is at full draw.
IBO Speed – The International Bowhunter’s Organization has a speed rating that is generally measured with a bow set at 70 pounds, 30-inch draw and shooting a 350-grain arrow. Speed is all the rage nowadays but don’t lose sight that it is not as important as manufacturers might lead you to believe. Note that unless you are shooting the same specs used to attain IBO speed ratings, your bow of choice will not shoot as quickly as you might think.
Peep Sight – used as the rear sight of a gun is used. The peep sight is placed on the bowstring and the sight pins and target are viewed through the peep. Peep sights come in different apertures so test a few sizes out and settle on the one the best fits your requirements.
String silencer – typically rubber components of various shape and size that fit onto the bow string in order to reduce the noise and vibration on the string once released.
DID YOU KNOW?
Holless Wilbur Allen, Jr. created the first compound bow in the early 1960’s, and was given a patent on his design in 1969.