How to choose your arrow spine?

But how to choose it correctly? What is the right method to use to avoid making a mistake? To answer these questions, in today's topic, we will discuss the essentials to know about arrow spines.

Spine: what is it?

In the list of different parameters that define the characteristics of an arrow besides its length, mass, etc., there is "the spine". The spine is a numerical value that is inscribed on each shaft. It corresponds to its stiffness. Indeed, the higher the spine value, the more flexible the arrow. Conversely, the lower the spine value, the stiffer the arrow.

The spine is a very important element in archery, because for an arrow to be operational, it must be adapted to the power of a bow. Indeed, a spine that is too low, meaning too rigid, will cause a lateral deviation of the arrows on the target.

It should be noted that the range of spines is quite wide. For example, we have spines of 370, 400, 430, 470, 520, 570, 670, 780, 1000, 1100, 1200 and more. On an arrow, the indication 420 (for example) means that the spine is 0.420 inches.

How to choose your spine correctly?

To choose your arrow spine correctly, you must first determine the power of your bow using a scale. Then, it's also important that you define your draw length using a graduated arrow. These two points will be your starting point.

After noting this information, you could use the spine charts to choose the correct spine that corresponds to the power of your bow and your draw length.

What are the spine charts?

Here are some examples of spine charts:

• Easton
• Carbon Express for competition arrows
• Carbon Express for lightweight arrows
• Skylon
• Gold Tip
• Aurel

How to use the spine charts?

To use the spine charts correctly, you will need to start by choosing your power range according to the speed of your bow and according to the desired arrow length. Then, when you cross-reference this data in the chart, you will find a selection of suitable spines according to several parameters including:

• The weight of the point,
• The use of wraps,
• The type of fletching used.

It should be noted that it is always preferable to start with a stiffer arrow rather than a spine that is too flexible.

Our tips for reading the spine chart correctly

To read the spine chart correctly, we advise you to round your draw length down to the nearest whole number. For example, if you have a 29.7 draw length, it's preferable to stay in the 29 box to avoid having a shaft that's too stiff.

If your power is at the limit of another range, we advise you to choose the spine of the lower range only if you are certain that you will not increase your power later. For example, if you have 34.5 pounds and you find yourself between the 30/34 and 35/39 range.

Another way to determine arrow spine

Here's another way (traditional method) to help you determine the arrow spine:

• Place your shaft on two support points that are 71 cm (28 inches) apart.
• Hang a weight of 880g (1.94 pounds) at the center of the shaft
• Measure the curvature that the shaft has taken due to the weight you just applied. The vertical gap between the shaft and the horizontal line drawn between the two support points, expressed in 1/1000th of an inch, corresponds to the spine of the shaft.

In summary, given that the arrow is an important element in archery, the choice of spine should not be taken lightly, as it directly affects your shots. Therefore, it is always recommended to use the chart to choose it correctly.