What is the Idler Wheel in Archery?

The idler wheel is a circular disc that is mounted on the axle of a compound bow. It is also known as the cam, and it is one of the key features that distinguish a compound bow from a traditional bow. The bowstring passes over the top of the idler wheel and is then attached to the bow's limbs.

How does the Idler Wheel Work?

The purpose of the idler wheel is to reduce the amount of force that the archer needs to exert when drawing the bowstring. In a traditional bow, the amount of force required to draw the bowstring increases as the string is pulled back further. This can make it difficult for archers to maintain a consistent draw length and can cause fatigue over time.

In a compound bow, the idler wheel is designed to take on some of the force that is required to draw the bowstring. As the archer pulls back on the string, the idler wheel rotates, and the bowstring is redirected around the wheel. This changes the angle of the string, which reduces the amount of force required to draw it back further.

Types of Idler Wheels

There are different types of idler wheels that can be used in compound bows, including single-cam, hybrid-cam, and dual-cam systems.

Single Cam Idler Wheels

Single-cam idler wheels are the simplest type of idler wheel system. They feature one idler wheel and one power cam, which work together to reduce the amount of force required to draw the bowstring. The power cam is an elliptical shape that is designed to store energy as the bowstring is drawn back and then release that energy to help propel the arrow forward.

Hybrid Cam Idler Wheels

Hybrid cam idler wheels have two idler wheels that work together to reduce the amount of force required to draw the bowstring. The cam shapes are typically asymmetric, with one side having a larger radius than the other. This creates a smooth draw cycle and helps to reduce string torque.

Dual Cam Idler Wheels

Dual cam idler wheels have two idler wheels that work independently to reduce the amount of force required to draw the bowstring. The cam shapes are typically symmetric, with both sides having the same radius. This creates a fast and powerful draw cycle but can also make the bow more difficult to tune.

Advantages of the Idler Wheel

Here are some advantages of using an idler wheel in a compound bow:

Reduced Draw Weight

The idler wheel works together with the cam to create a mechanical advantage that reduces the amount of weight the archer has to hold at full draw. This can make it easier to draw the bow and hold it steady for longer periods of time, which can be especially important when hunting or competing.

Increased Let-Off

Another advantage of using an idler wheel in a compound bow is that it can increase the amount of let-off, which is the percentage of draw weight that is released once the bowstring is at full draw. The idler wheel helps to store energy in the bow, which is then released when the bowstring is released. This means that the archer can hold less weight at full draw, which can be more comfortable and reduce fatigue over time.

Consistency and Accuracy

The idler wheel helps to create a more consistent draw cycle, which can result in more consistent arrow speeds and better shot placement. Additionally, the reduced draw weight and increased let-off can help you hold the bow steadier at full draw, which can also contribute to more accurate shots.

Customizability

Different types of idler wheels and cam systems can be used to achieve different performance characteristics, such as speed, power, and ease of use. This means that you can choose an idler wheel system that best fits your shooting style and needs as an archer.