Aside from working on your shooting technique, knowing the technical aspect on how your compound bow shoots arrows will help you develop a keen archery sense. Also, knowing how a compound bow works will give you a good idea on how to select the right kind of gear for you. Let’s find out more below.
How a Compound Bow Works: Focusing on the Parts
To point it out simply, all types of bows work by having an arrow drawn back on a bow string, with energy and tension building up as you tak aim. The energy is then released once you let go of the bow string, launching the arrow towards your target.
Now, the farther you pull back on the bow string, the greater the tension or the weight you'd feel. It does take some practice and skill getting the right feel and stance when shooting the conventional way.
For compound bows, an innovative process was created to counter the heavy sensation whenever you'll pull on the bow string. The compound bow's cam system is geared so, that when holding the bow at the full draw length, you do not have to counter the full draw weight. Simply put drawing a compound bow is hard, but holding it is easy - so aiming such a bow is a breeze.
Let’s break down the process by discussing a compound bow’s main parts:
Pulley System
One of the main reasons why compound bows is a popular choice among archers is that it'll allow you to use a bow with high poundage without so much of an effort.
Conventionally speaking, the pulley system integrated within a compound bow takes out approximately 80% of the bow's draw weight at full draw. The amount taken off is termed as "let-off".
To paint a clearer picture, a compound bow with a draw weight of 60 lbs. would require you pulling only 12 lbs. when at full draw. The pulley system makes this possible - not so much stress to handle when handling a heavy bow!
This means it's a lot easier to hold a compound bow at full draw height while aiming, versus a recurve bow where you need to hold the full draw weight at the full draw height.
Limbs
These are the parts that contain and spread out the energy released when drawing the bow string. Compound bow limbs need to be durable enough to withstand pressure generated from the pulley system as well.
Cams
Focusing more on a key part of the pulley would be the cams. Usually located at the limbs (the tip edge), these rotating (some, sliding, depending on the design) mechanisms help in lowering the draw weight when you're going at full draw.
Also, an important factor to consider is that you can only shoot a compound bow when it is at full draw. As such, you may want to choose a cam that will best fit your style - there are all sorts of cam variant designs, from creating faster shots to better bow handling.
Aside from the cam variants, there are also different cam configurations to consider. We will be tackling these configurations on a separate section below.
Riser
This is the central section of the compound bow. The riser holds together the key components of the bow (the rest, limbs, sight, stabilizers, etc.). Considering the many parts attached (and can be attached) to the riser, this component needs to tough yet light. Contemporary risers are made to withstand tension - yet still be light enough to handle.
The Actual Compound Bow Working Process
Now, let’s get more specific. Here is the conventional flow on how compound bows make arrows fly:
- Arming the Arrow – conventionally, this is the part where you will place your arrow on the rest. But for cases a compound bow does not have an arrow rest, simple adjust by arming it in a traditional manner.
- Draw and Let the Pulley System Work its Magic – pull on your bow string at full draw. This motion makes the cable attached to your cams to move as well. As the cable moves, energy is spread out, compressing the compound bow's limbs as well. Which leads us to the next step of...
- Storing the Energy – the limbs will flex as you pull on your bow string. Think of these limbs as a spring. As pressure is applied, a spring gets compressed. Once you've released that tension, the spring then expands. This is exactly how a compound bow's limbs work. The energy you place on these essentials will be released once you let your arrow fly!
- Experience the Let-Off – as minuscule as it can be, try to notice this sensation the next time you draw your compound bow. As you pull on your bow string and as the limbs start to flex, your cams work on this motion by decreasing the amount of weight you're pulling. You are more likely to experience this let-off as you approach peak full draw position.
- Transferring the Energy Towards the Arrow – now here's the amazing part of what a compound bow can do. As you release your bow string, you'd notice that the limbs will flex again. This is how the energy is transferred towards the arrow. Going with the spring analogy, the more pressure applied (the higher the draw weight), the larger the expansion would be (your arrow will hit stronger).
All these happen in a single motion - isn't that amazing?
More About Cams
Now, let’s discuss the many cam configurations that you may want to try:
Single Cam System
Consider the simplest cam configuration. As such, not so much maintenance is needed for this choice. A single cam system has a unique cam located at the top limb and a conventional one at the bottom limb.
Called the idler wheel, the top cam simply unrolls the string as you go for a full draw motion. The bottom cam does the brunt of the work: from taking up the control cable of the pulley system to correcting the downward cable's motion. Considering this is a simple design, the single cam system configuration offers quiet shots. But energy release pales in comparison to the other cam configurations.
Twin Cam System
Also called two cam system, this configuration offers better accuracy and faster shots than a single cam configuration. However, this configuration tends to be noisier. Coming with two functional cams located at each end of a bow's limb, energy is distributed and stored properly.
You would need to have and keep a good eye on maintaining this configuration. Some twin cam system configurations are extra sensitive when it comes to synchronization. Nothing spells disaster more than having cams not rolling at the same time. As such, arrow flight may also suffer if you do not maintain this configuration regularly.
Binary Cam System
Improving the sometimes faulty design of the twin cam system, the binary cam configuration offers a perfect match when using the two power cams of the compound bow.
Instead of being attached to the limbs, the cams of this configuration are linked with each other. This corrects synchronization issues encountered in the twin cam system. The design also helps creating more accurate shots.
Hybrid Cam System
Similar on how a binary cam system configuration is designed, the hybrid cam system improves overall performance by adding some much-needed stabilization.
Making use of the single cam system's feature of an idler wheel, the top cam of this configuration stabilizes the power distributed by the bottom cam for a more balanced shot. Also, the linked attachment of both cams (similar to what's seen on binary cam configurations) means that synchronization will not be a problem.
Another feature that sets this system apart from binary cam configurations is the set "slave-master" cam design. A binary cam system has both cams mirrored and linked with each other's movements; a hybrid cam configuration has the set motions of a top idler wheel cam and a bottom power cam.
Miscellaneous Compound Bow Terminology You Should Know About
We’d also like to take the opportunity to discuss two of the most common terms when dealing with compound bows:
Let-Off
We've mentioned this term earlier - let us know try to shed more light on this phenomena. Depending on the bow, different let-off rates may be offered. Regardless of the let-off rate, you just need to choose which would be the most comfortable for you to use. Comfort, after all, is essential in archery. And these let-off values will get you in the right kind of shooting zone you need to be in!
As a rule of thumb to keep in mind, the higher the let-off, the easier you can expect to handle a compound bow.
Valley
The moment a cam transitions in making adjustments towards a full let-off - this is how most archers define what the "valley" is. Remember the 4th step we've mentioned in the flow above? That would be the closest to explain what the valley is.
It really isn't quantifiable - it's more of a sensation. You may not even feel it when you're shooting. But you're bound to get that feeling sooner or later when you've got your compound bow set up properly.
But why explain this sensation? Simply put, for the wrong reasons on how you may be using your compound bow. Cams that produce short valleys are more likely to be aggressive on shooters. If you've seen others feeling some discomfort or if they start to twitch when at full draw, more likely than not, the compound bow needs to be adjusted for a relaxed shot.
Bonus: Benefits of Using a Compound Bow
Since we're learning on how compound bows shoot, let us also share some quick reasons on how this type of bow is a beneficial choice that you should really maximize to the fullest:
When You Need Power
Particularly for hunters, compound bows give you the edge you need - without the hassle of exerting too much effort. The process explained above shows how energy storage, distribution, and release will result in higher arrow velocity shots.
When Speed is of the Essence
Compound bows shoot faster arrows. If you need fast arrows (with more energy), then this is the perfect bow for you.
Accuracy is Boosted
Given the let-off potential and ease of grasping the bow itself, compound bows will allow you to take a nice and steady shot towards your target.
Keeping You Safe
Since generally all compound bows have a low draw weight requirement, you'd be able to handle these bows with ease. And with it being easy comes a higher chance to keeping it safe while shooting.
Potential to Outfit the Best Accessories
Compound bows enjoy having a large market of archery accessories, which can enhance your performance. Some of the best sights in the market are created solely for compound bows.
Portability
Compared to other types, compound bows are generally smaller. This means that you do not need to bother lugging your gear with you all the time. With less weight to manage, you'd be able to focus on what you need - your target(s).
Several Cam Configurations to Choose From
Aside from the actual compound bow construction and design, there are several cam configurations to select. Knowing what each configuration has to offer you will let you find out on what's the right bow for you.
Built Tough
Perfect for use out in the wild, compound bows are known to withstand even the harshest elements that nature can throw at you.
Make the Most Out of Your Compound Bow
Maximizing your compound bow's potential begins when you start learning more on how it works. From knowing how energy is stored when shooting, to the many types of variations or configurations to choose from, having these details in my mind will give you a clear idea on how to approach (and attain) the archery experience you have always desired. Good luck, and we hope you get to choose the right compound bow for you!
Read More
Here are some helpful links to let you know more about compound bows.
Science to the rescue! This fun and informative post explains more on how energy factors in when you shoot an arrow.
Here's a nice article explaining more on how compound bows work.
Watch how to shoot a compound bow properly in this World Archery Video.