Cam timing is a very important aspect of owning a compound bow that is often overlooked by many archers. The cams on your bow control the strings and cables of your bow. This means they play an essential part in a functioning and accurate compound bow.

But, from time to time, cams will need to be inspected and adjusted to ensure they are performing properly. This is where the cam timing and cam lean will come into play!

What Is Cam Timing and Cam Lean?

Cam timing refers to how well the cams on a bow are rotating in synchronization. The vast majority of bows shoot much better when the cams rotate at the same exact time. If they do not rotate at the same rate, one will stop before the other and create problems in the string which can torque the arrow upon release.

Cam lean is another common issue with compound bows. Cam lean is when the cams are at a different angle from the plane of the cam to the vertical plane of the bow. It is very similar to how a car with too much weight would look. Imagine you are standing in front of a car and all of the passengers inside are sitting to one side. The car would be leaning to that side instead of being perfectly level.

This is the same concept with the cams on a compound bow. The various strings and cables on the bow create levels of tension through the drawing process. When a string or cable is pulling differently than its counterpart, it results in cam lean. Every compound bow is different, and some are more prone to cam lean than others.

How to Test Cam Timing and Cam Lean

To determine if your bow suffers from cam timing issues, both of the draw stops should contact the cable or limb at full draw. If one of them makes contact before the other, you have a cam timing issue that will need to be adjusted.

Both cam timing and cam lean can be tested by visually inspecting them. This is often the least efficient and reliable method to know if your bow is suffering from these issues. To see if you have timing issues, have a friend watch your draw and pay close attention to the draw stops and when they hit.

A much better way to test timing is to use a draw board. A draw board is a simple device that you place your bow inside and draw with a mechanical crank. This allows you to slow down the draw rate in order to examine when the draw stops hit and if the cams are properly timed.

Cam lean is much easier to visually inspect and find problems. A quick trick is to place an arrow shaft on the cam wall and compare the angle to your bowstring. If the arrow runs parallel to the string, the cam is properly aligned. If the angle is off, you have some cam lean.

What is Single Cam Timing?

Some compound bows rely on a single cam in order to function. Many people would believe that because of this, timing isn’t important. This, however, is not the case as the single cams must only rotate a specific amount in order to be fully optimized. If this rotation is off, then the cam’s performance may also suffer.

You can tell if a single cam has timing issues by looking for a timing mark that will allow you to see if it is off or not. This timing mark varies from manufacturer to manufacturer, but it’s often a hole in the cam or specific marks on the cam. If a single cam bow is properly timed, you should be able to look through the hole in the cam and see the cable centered inside of it.

What is Dual Cam Timing?

Most modern compound bows utilize dual cams. With these bows, it is important that both cams roll and move in sync with one another. If one cam completes its full rotation before the other, then you have a timing issue. This results in your pull at full draw being uneven. Bad timing issues with dual cams can lead to accuracy and consistency issues. Some bows still perform fine even if the dual cam timing is a little off, but this comes down to an archer’s personal preference.

How to Adjust Cam Timing

Single Cam

1. Inspect the Timing Hole or Mark

Check your cam with the timing hole or mark to see if your bow is properly timed. As a general rule of thumb, the cable of the bow should be running through the center of the hole if everything is perfectly timed. If not, you know you have timing issues.

2. Place Bow in Bow Press

If your single cam bow needs the timing adjusted, you will need to change the position of the timing holes on the cam in relation to the bowstring or cable. Place the bow in a bow press in order to safely work on it.

3. Twist/Untwist Bowstring or Cable

Once the tension on the bow has been released through the bow press, you can change the cam rotation and position by twisting or untwisting the bowstring and/or cable. Check with the bow manufacturer to determine which one should be adjusted to affect the cam on your single cam bow.

4. Recheck Timing, Test Bow

After adding a few twists in either the bowstring or cable, test the draw of the bow once again. Take the bow out of the press and see if the timing hole or mark is now properly aligned. Repeat this process until you get this right.

Dual Cam

1. Inspect Cams to Determine Timing

With a dual cam bow, it is often recommended that both cams hit their stops in synchronization. While this is not always required, it is a great place to start for most archers. To begin, check to see how well your cams are working together. Have a friend watch you draw your bow or use a drawing board to inspect for timing issues.

2. Place Bow in Bow Press

Place your bow inside of a bow press to release the tension on the cables and bowstring. If you see that one of your cams is slower than the other, you simply need to add a few twists to the cable on the cam that stopped first.

3. Twist/Untwist Cables

Place a few twists in the cable. Remember to only try small increments at first, as they will go a long way. Take the bow out of the press and review the cam timing. If both cams are not coming to the stop at the same time, repeat the process by adding another twist or two.

4. Reevaluate Timing, Repeat Process as Needed

Repeat this process until you get both cams perfectly timed. If you overdo it, simply undo a twist or two in the cable that you have been working on. Examine the cams during the draw process to affirm that both are working in sync.

How to Adjust Cam Lean

1. Inspect Cams for Lean

Examine your cams to inspect for cam lean. Cam lean is best checked using a draw board. You will lay an arrow across the surface of the cam and confirm if it’s in line with the bowstring. If you do not have a draw board, have a friend stand behind you while at full draw. They can then examine the cams to see their positioning.

2. Put Bow Inside Bow Press

To fix any cam lean, you will need to place the bow inside of a bow press. This will take the tension out of the bowstring and cables to allow for adjustments.

3. Adjust Yoke Harness(s)

To make adjustments, you will need to adjust the string yoke harnesses by twisting or untwisting them. If the cam is leaning to the left, make one full twist to the left side of the split-yoke harness. If it leans to the right, make the adjustment to the right. Make one twist at a time until the cam is more or less straight up and down.

4. Reevaluate Lean, Repeat Process as Necessary

Take the bow out of the press and reexamine the cam lean. If there is still a significant amount, repeat the process and add/remove more twists to the appropriate side. Make sure you do not overdo it, however, as too many twists on one side can cause the string to jump off the rail of the cam.

Final Thoughts

Cam timing can cause accuracy and consistency issues without the vast majority of shooters realizing it. Over time, a compound bow can experience cam timing issues or cam lean that need to be addressed. Luckily the process is fairly simple. With a few pieces of equipment, you can properly set your cam timing and fix cam lean to ensure a perfect compound bow!