Recurve Bow String Length Calculator
Recurve Bow String Length: The Definitive Guide
Getting the correct bow string length for your recurve bow is critical for optimal performance and preventing damage to your equipment. However, determining the right string length can be confusing, especially for beginners. In this guide, we’ll cover everything you need to know about recurve bow string lengths, including industry standards, measurement methods, and how to choose the ideal length for your bow.
Understanding AMO Standards
The Archery Manufacturers and Merchants Organization (AMO) has established standards for measuring bow and string lengths to ensure consistency across the industry. According to AMO standards, the correct bowstring length for a recurve bow should be approximately 3 inches shorter than the stated bow length.
For example, if you have a 68-inch recurve bow, the AMO standard would recommend a 65-inch bowstring (68 inches – 3 inches = 65 inches).It’s important to note that while the AMO standard is widely accepted, some manufacturers may have slightly different recommendations for their specific bows. Always check your bow’s documentation or consult with the manufacturer for their recommended string length.
Measuring Bow Length
To determine the correct string length, you first need to know your bow’s length. Here’s how to measure a recurve bow’s length according to AMO standards:
- Unstring the bow and lay it flat on a level surface.
- Measure from the string groove on one limb tip, following the curve of the limbs, across the riser, and to the string groove on the other limb tip. This measurement should follow the bow’s belly (the side facing you when shooting).
- The measurement you obtain is the bow’s AMO length.
Here’s a handy table showing common recurve bow lengths and their corresponding AMO string lengths (3 inches shorter):
| Bow Length (inches) | AMO String Length (inches) |
|---|---|
| 62 | 59 |
| 64 | 61 |
| 66 | 63 |
| 68 | 65 |
| 70 | 67 |
| 72 | 69 |
Measuring Recurve Bow Length
Factors Affecting String Length
While the AMO standard is a good starting point, several factors can influence the ideal string length for your recurve bow:
- Bow Design: Different bow designs may require slightly longer or shorter strings to achieve the optimal brace height (the distance between the grip and the string when strung).
- String Material: Strings made from different materials (e.g., Dacron, FastFlight, Dyneema) can stretch or creep at different rates, affecting the final string length needed.
- Personal Preference: Some archers may prefer a slightly longer or shorter string length to fine-tune the bow’s performance or feel.
- Brace Height: The desired brace height can also influence the string length. A longer string generally results in a higher brace height, while a shorter string lowers the brace height.
To account for these factors, it’s often recommended to start with the AMO standard length and then make minor adjustments as needed based on your specific bow and preferences.
Choosing the Right String Length
When selecting a string length for your recurve bow, consider the following guidelines:
- Start with the AMO Standard: Begin by ordering a string that matches the AMO standard length for your bow (3 inches shorter than the bow length).
- Check Manufacturer Recommendations: Consult your bow’s documentation or contact the manufacturer to see if they recommend a specific string length for your model.
- Consider String Material: If using a modern string material like FastFlight or Dyneema, you may need a slightly shorter string than the AMO standard to account for less stretching.
- Adjust for Brace Height: If you prefer a higher or lower brace height, you can adjust the string length accordingly. A longer string will increase the brace height, while a shorter string will decrease it.
- Fine-tune with Twists: Once you have the correct string length, you can fine-tune the brace height by adding or removing twists in the string. More twists will shorten the string and lower the brace height, while fewer twists will lengthen the string and raise the brace height.
Remember, the goal is to find a string length that allows you to achieve the desired brace height while maintaining optimal performance and avoiding excessive stress on the limbs or riser.
Nock Fit and Tuning
In addition to affecting brace height and performance, the string length can also impact nock fit and tuning. The nock is the component of the arrow that attaches to the bowstring, and proper nock fit is essential for consistent arrow flight and accuracy.
If the string is too thick for the nock, the arrow may not release cleanly, resulting in poor accuracy and potential dry fires (the arrow releasing before the string is fully drawn).
Conversely, if the string is too thin, the nock may not grip the string properly, leading to inconsistent arrow flight.
When selecting a string length, consider the nock size of your arrows and ensure that the string’s center serving diameter is compatible. Many string manufacturers offer different strand counts or serving materials to accommodate various nock sizes.
Replacing Your Recurve Bowstring
Over time, even the highest-quality bowstrings can wear out or lose their optimal performance. It’s generally recommended to replace your recurve bowstring every 1-2 years, depending on your shooting frequency and the string material.When replacing your bowstring, follow these steps:
- Measure your existing string’s length (following the AMO method) to determine the replacement length needed.
- Order a new string from a reputable manufacturer, specifying the correct length and material.
- Carefully install the new string, ensuring proper brace height and nock fit.
- Fine-tune the brace height and nocking point as needed.
By following these guidelines and regularly replacing your bowstring, you can ensure optimal performance, consistency, and safety when shooting your recurve bow.
Conclusion
Choosing the correct recurve bow string length is crucial for achieving peak performance, accuracy, and longevity for your equipment. While the AMO standard provides a solid starting point, factors like bow design, string material, and personal preference may require slight adjustments.
Remember to measure your bow length accurately, consider the string material’s properties, and fine-tune the brace height and nock fit as needed. With the right string length and proper maintenance, you can enjoy a smooth, consistent shooting experience with your recurve bow for years to come.