When it comes to crossbows, many things need to be considered to ensure an accurate shot. One of the most important factors is the length of the crossbow string. How do you measure the string, and how to ensure that you order the correct size? Read on to find out.

How to Measure Crossbow String Length?

The first place to look is the manual. If you don’t have the manual, look online for the make and model of your crossbow.

Once you have the manual, find the section that pertains to string replacement. This will give you the specifications needed to purchase the correct size string.

Contact the manufacturer if you don’t have a manual or can’t find the information needed. They should be able to help you out.

Another way is to tune your crossbow, and once everything is set to where it needs to be, and you are happy with the results, measure the string.

So, in short: 

  • Look up the section of the manual that pertains to string replacement.
  • If you don’t have a manual or can’t find the information needed, contact the manufacturer.
  • Tune your crossbow and once everything is set up perfectly – remove & measure the string.

Are all Crossbow Strings the Same?

No. Not all crossbow strings are the same. You can buy crossbow strings made specifically for your make and model of the crossbow. These strings will be the correct length and have the right amount of stretch. They will also be made from materials that are compatible with your crossbow.

Southland Archery Supply 150Lb Crossbow...

Or you could order a custom-made set of strings and cables. Make sure to send in your old string (yes – with the exact number of twists); this will make it much easier for the string shop to make a set that will fit your crossbow precisely.

What is the Serving on a Crossbow String?

The string serving on a crossbow is approximately four inches long and tightly wound around the string.

“The serving performs a number of tasks. It protects the string material, provides a consistent surface for release from the trigger mechanism, reduces friction on the track, and protects the loaders fingers from potential damage by covering possible pressure points on strands of string material.”

Source: National Crossbow Federation

How do you Serve a Crossbow?

If you are a beginner. You don’t! If you know what you’re doing, be careful! Here’s a video explaining how to do it:

Excellent video series by Don Katsumi!

Do you Wax Serving on Crossbow?

There is conflicting information on this. Most manufacturers don’t recommend it as it can potentially damage the string.

If you decide to wax the serving on your crossbow, be careful not to get any wax on the actual string material. Waxing the serving can cause premature wear of the string and may interfere with arrow flight.

But some manufacturers do recommend it. So, if you have a high-end crossbow and the manufacturer says it’s okay to wax the serving – then, by all means, do it!

Tenpointcrossbows“If your crossbow has exposed strands of the string or cables that are not served, then a coating of bowstring wax should be applied to the exposed strands.”

Excaliburcrossbow: “EX-WAX – Apply to string serving for longer life. Comes in a handy resealable container.”

Barnett RX 150 user manual“Apply lubewax to the center serving of string, rolling string forwards and backwards to ensure even application of wax.”

If unsure, contact customers support and ask before you wax the serving on your crossbow.

Do you Twist a Crossbow String?

Yes, you do! To keep the serving tight, twist the string counterclockwise. A string twisted in the opposite direction from how the serving was applied will loosen, resulting in premature string failure.

Do Crossbow Strings Stretch?

Yes, they do. Some of the string materials on factory crossbows are not top quality. Or the manufacturer didn’t apply enough tension when they built them. High draw weights require more tension and better quality string material to minimize stretch. 

How Often Should you Change the String on a Crossbow?

There is no set amount of time for a crossbow string. Many factors affect the lifespan of your crossbow string, including its material, tension, and length.

One of the most significant factors in how long your crossbow string will last is how well you take care of it.

Most people recommend changing their crossbow strings every two years, but it’s not unheard of that some crossbow users have been shooting with their crossbow strings for up to 4 years!

How many Shots does a Crossbow String last?

How it will last depends on several factors. As mentioned above, your crossbow string’s lifespan will significantly affect its material, tension, and length.

In addition, how often you use your crossbow and how well you take care of it will also play a role in how long your crossbow string lasts.

Generally, most people get around 100-250 shots out of their crossbow string. Some get even way more, but it’s always best to air on the side of caution and change your crossbow string every two years.

Should you Unstring a Crossbow when not in Use?

No. I believe it is okay to leave your crossbow strung. But if you are referring to leaving it cocked, then the answer is yes. It is 100% recommended that you uncock your crossbow. This will help to prolong the lifespan of your crossbow string.

The reason for that is simple. When a crossbow is cocked, the string is under constant tension. Over time, this tension will cause the string to stretch and eventually break.

By decocking your crossbow when not in use, you are essentially giving your crossbow string a much-needed break and helping to prolong its lifespan.

How Long can you leave a Crossbow Cocked?

We reached out to Bear Customer Care and asked how long their X Saga 405 can remain cocked. And they recommend not keeping it cocked for longer than 5 hours. 

Uncock the bow for 30 minutes and give the string time to “de-tension.” So, if you plan to use your crossbow for an extended period, uncock it every 5 hours.


There are different ways to determine the length of a crossbow string. Check the manual; if you don’t have it, look online or contact customer support. The length of the string will be different for every crossbow model.

If you are looking for a custom-made string, tune your crossbow, remove the string and send it to the string maker. They will then be able to make a string that is the perfect length for your crossbow.

There is no set amount of time when it comes to replacing your crossbow string. It all depends on the quality of the string, how often you use your crossbow, and how well you take care of it. Most people recommend changing your string every two years or so.

3 thoughts on “How to Measure a Crossbow String”

  1. My crossbow is a Centerpoint Specialist and it is 3 years old. I’m estimating it has around 250 shots on it. I am experienced in fine tuning vertical bows and wonder if some of the same principles apply with respect to string and cable twists on crossbows. I have found almost nothing on the internet on this topic. If, for example, on my vertical compound bows, I want to slightly lengthen the draw, I can put some twists in the buss cables (I know this pre-stresses the limbs and makes it a hotter setup, but I’m talking a small number of twists). If I wanted to shorten my draw I can add some twists to the string and so forth. My question is, (recognizing there are important limits), could I adjust string and cable twists on a crossbow in a similar way? I want to return my (relaxed bow) axel to axel distance back to specifications since it has lengthened an eighth of an inch over these past three years, and it has lost about 10fps at 15 yards with the same arrow weight from three years ago. The string and cables look brand new, as I take good care of them. I have some new rigging on order from Centerpoint, but wonder about this kind of fine tuning as a viable option in the meantime. Your input would be appreciated. Thanks in advance.

    • Hello,

      First of all, thank you for reaching out with your question. We are always happy to help our audience in any way possible.

      It is indeed possible to twist a crossbow’s strings/cables as you have described to modify its effective draw length. However, this should be done carefully, and in extreme moderation. As I am sure you are well aware, a few twists in one direction or another can go a long way. It would also not be a bad idea to email Excalibur directly, as they can likely provide you with additional guidance regarding any manufacturer-specified limitations that might pertain to such adjustments.

      It is also worth mentioning that some crossbows tend to be more accurate when operating at one specific brace height, rather than another. Since twisting a crossbow’s strings/cables as you have described modifies a unit’s overall brace height, you might find that this method of tuning slightly affects the forgiveness of your crossbow.

      • Hello again,
        In-between my original post and your reply I was able to try some adjustments by gradually adding twists to the string and cables, taking some bow and speed measurements and continuing from there. Before starting I made careful pencil marks on the cams to see what direction and how far they rotated with each number of twists. And at the beginning I plotted a force-draw curve with the bow, while I had it detached from the rail. Here is a quick summary of everything so far.

        Over a period of days I ended up adding 10 twists to the string, and 5 to each bus cable. This resulted in positioning the cams exactly where they started, and making the relaxed axel to axel length to 3/16th’s inch shorter than the stretched out (3 year old) bow. The drawn axel to axel length is now 3/8th’s inch shorter. This change added approximately 25 foot pounds to the area under the force-draw curve, and restored my bolt speed (with the same arrow from three years ago (449 grains)) back to just 1 fps slower than I had recorded when the bow was new. I did not measure brace height that you mentioned, but the tiller on each limb ended up 1/16th inch longer on each side. I’m going to sight in again to see what happens there, as soon as I can.

        At the end of the day, I hope to replace this old rigging, as I expect to receive a new string and cables (totalling $70) from the manufacturer, Centerpoint very soon. I did ask Centerpoint what the number of string/cable twists should be from the factory, but have not heard back just yet. If I do not hear back, my plan for the new rigging is to put the same number of twists I currently have, but only after subtracting what I added to accommodate for the three years of stretching.

        This was a good learning experience for me, and I hope some of your readers will benefit as well. Again, I’ve found virtually nothing but your reply when searching this topic online, so thanks very much for your continued input.


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