The Complete Guide to Compound Bow Cams

Nov 21, 2022Bow Tuning and Repair, Compound

Modern compound bows are an incredible feat of technology. The compound bow cam is the main component that gives these bows their amazing power and speed. Here is everything that you need to know about compound bow cams and how to get the most out of their design!

What Is A Compound Bow Cam?

The cams are the unique parts of a compound bow that are round or oval in shape. They can be found at the end of the bow limbs and are what make a compound bow a compound bow.

Cams come in many different styles and shapes. There are single cams, hybrid cams, binary cams, and dual cams. Every bow manufacturer will have various styles of cams on their bows, but they all serve the same purpose: giving power to your bow while making it easier to hold at full draw and shoot.

How Does A Compound Bow Cam Work?

Compound bow cams are specially designed to manipulate the draw weight of the bow. Once you get past a certain point, the weight that you feel drops. Even though you are holding back less weight, you still get the same amount of stored energy at the shot.

A cam does its job thanks to its design. They work inside of a cam system that transfers energy from the bow’s limbs into the bowstring while making it easier to draw back and hold. Thanks to this series of cams, pulleys, and cables, the cam system creates a bow that is easier to shoot and extremely powerful.

Speed and Cam Profiling

There are several shapes of bow cams on the market today, and these have a direct correlation to the bow’s speed. These are generally classified into different categories like round, medium, and hard cams. Let’s start with round cams.

Round cams were the first type and shape of cams that compound bows featured. During the ’80s, many bow manufacturers began moving away from these circular cams. They did this in favor of more egg-shaped cams that produced more speed, but you can still find models today that use round cams. Round cams produce some of the smoothest draw cycles you will find, but do so at the loss of speed.

On the other side of the spectrum, you have hard cams. As people became more and more obsessed with speed, compound bow cams evolved and changed. This produced hard cams or those that were able to store more energy and produce higher speeds. This comes at a price, however, since they are usually a little harder to draw.

Most bows fall under the medium cam category, giving you a good blend of speed with a smooth draw cycle. Almost all modern compound bows have cams that fall into one of these categories, each with its own set of advantages and disadvantages.

Types of Compound Bow Cams

In addition to the various cam styles, there are a few different types of compound bow cams to choose from. When it comes to compound bow cams and decisions, this is the most often asked question. What are the various types, and what are they good for? Let’s take a quick look at each of the types and what makes them unique.

Single Cam Bows

Single-cam bows are very common, especially among starter compound bows. These bows use a round idler wheel at the top of the bow and a single power cam at the bottom. Single-cam bows are usually a little quieter and easier to work on than other types. When it comes to tuning and maintenance, single-cam bows are the clear winner. They give you a functional and basic system, but one that is very effective. Thanks to the rise in technology, single-cam bows have come a long way since their inception. This is why they are the most popular option on the market.

Dual Cam Bows

Dual cam (sometimes called twin cam) bows have two separate cams that work together in order to produce higher draw weights and energy. With two cams producing energy, you get a lot more speed. With more speed comes improved accuracy. Both of these cams can be in any style, but they must be the same style in order to be synchronized and work together. Dual-cam bows provide more power and speed than single-cam bows, but they do require more work and tuning. If the two cams are not working entirely in sync, you can experience performance issues.

Hybrid Cam Bows

Hybrid cam bows are very similar to dual cam bows. They are designed to help solve the synchronization issues that can sometimes occur with dual-cam bows. But while hybrid cam bows use two cams like a dual cam bow, they only utilize one power cam and one control cam. The control cam follows the power cam, forcing them to work in harmony. This makes both cams automatically in sync and much easier to tune. With great speed and power like a dual cam, hybrid cam bows generally have much less maintenance than a dual cam as well. Of course, when they do need work, they can be harder to work on (especially compared to single-cam bows).

Binary Cam Bows

The last type of bow cams are called binary cams. These take hybrid cams to another level. With binary cam bows, you have two active cams similar to a dual cam bow. In this setup, however, both cams are able to work independently of one another thanks to the cable system. Instead of pulling on opposing limbs, they only pull on the opposing cam. This system allows the cams to correct any imbalances and helps avoid timing issues. This means you get excellent speed and power, although binary cam bows can be harder to work on due to their more complex design. Unfortunately, there are many patent issues with binary cam bows, so it is not uncommon to see many manufacturers produce “hybrid cam” bows that are actually binary cam with a different label.

Compound Bow Cams and Let Off

Every compound bow will have some degree of let-off. Most compound bows will have let off between 60 to 90%. This can and does vary between different models, brands, and styles. Their overall design will dictate just how much let-off you can expect. Because let-off is produced by the elliptical shape of the cams, it plays an important role in how much let-off you can reasonably expect.

The more elliptical of a shape a cam has, the higher let-off it can produce. This comes at a trade-off, however, as it will usually not have as smooth of a draw cycle. Many compound bows also include ways to manipulate the let-off and change it, thanks to adjustments that can be made on the cams.

Which Compound Bow Cam Works For Me?

Now that you have a better understanding of the various types and styles of compound bow cams, which one should you choose? This will come down to your personal preferences. While most archers start out with a single-cam compound bow, that doesn’t mean you have to. Your skill level could be an important factor to consider, however, as some types are easier to work on and tune than others.

For beginners or those that want a lower maintenance bow, a single cam might be the way to go. Dual-cam bows will be the best choice for those that desire speed and power over all else but they will come at the price of more tuning and work. This is why many archers opt for binary or hybrid cam bows, as they offer a good blend of power and accuracy without worrying as much about tuning or maintenance.

Compound Bow Cam Replacement

One of the best things about using a mechanical system like a compound bow is that parts can be changed or replaced. This also holds true for compound bow cams. Most bow manufacturers produce replacement cams for the models that they sell. You can replace the bow cams in the event that they are damaged or you simply want to upgrade them.

Bow cams can be bought from the manufacturer directly, or a bow shop can order them for you. This is usually the best route, as the bow shop can then install the new bow cams for you with all of their tools and knowledge. Compound bow cams can cost anywhere from $50 all the way up to $400. It is important, however, to get bow cams specifically designed for your model of compound bow.

Final Thoughts

Compound bows are incredible feats of engineering and technology, and all is made possible thanks to the bow cams. Although bow cams come in a variety of different shapes and styles, there is sure to be one that fits your needs and preferences. With that being said, I hope you were able to learn everything you need to know about compound bow cams. Good luck and happy shooting!

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  1. Ana

    Thank you. Very helpful information.

  2. Kenneth Fracchia

    I am working on a project that requires an idler cam. Do you know if cams made by different manufacturers all have the same diameter axel? The cams that I have seem to use and 3/8 diameter axel. Is this common for most cams?

    • Marc

      Thanks for the question, Kenneth! Using a cam by a different manufacturer is a roll of the dice. I believe your best course of action is to get in contact with the bow manufacturer and ask them. There may be some subtleties that are crucial for optimal performance. If that particular bow/cam isn’t made anymore, they may help you find a suitable replacement that will work. Best of luck!


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