But how do you choose it correctly? What is the right way to make sure you don't make a mistake? To provide an answer to these questions, in our topic of the day, we're going to talk about the essentials you need to know about the spines of an arrow.
Spine: what is it?
Among the list of different factors that define the characteristics of an arrow besides its length, mass, etc. there is " the spine ". The spine is a numerical value which is written on each shaft. It represents its rigidity. Indeed, the higher is the spine value, the more flexible is the arrow. On the contrary, the lower is the spine value, the stiffer is the shaft.
The spine is a very important component in archery, because for an arrow to be operational, it must be suitable for the power of a bow. Indeed, a spine that is too weak, i.e. too stiff, will cause a lateral deviation of the arrows on target.
It should be noted that the range of spines is quite large. We have for example 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 inch.
How to choose your spine correctly?
To choose your arrow spine correctly, you must first determine the power of your bow by using a weighing scale. Then, it is also important that you define your draw length using a graduated arrow. These two points will be your starting point.
After recording this information, you can use the spine charts to choose the right spine for your bow's power and your draw length.
What are the spine charts?
Here are some examples of spine charts:
- Carbon express for competition arrows
- Carbon express for light arrows
- Gold tip
How to use the spine charts?
To use the spine charts correctly, you will need to start by choosing your power range according to your bow speed and desired arrow length. Then, when you cross-reference this data in the table, you will come across a selection of spines adapted according to several parameters including:
- The weight of the tip,
- The use of wraps,
- The type of feathers used.
Note that it is always preferable to start with a stiffer arrow rather than a spine that is too soft.
Our tips for reading the spine chart
To read the spine chart correctly, we advise you to round down your draw length to the nearest whole number. For example, if you have 29.7 length, it is better to stay in the 29 box to avoid having a too stiff tube.
If your power is on the borderline of another range, we advise you to choose the spine of the lower range only if you are sure not to increase your power later. For example, if you are 34.5 pounds and are between the 30/34 and 35/39 range.
Another way to determine the arrow spine
Here is another way (traditional way) to help you determine arrow spine:
- Place your shaft on two support points that are 71 cm (28 inches) apart.
- Hang a weight of 880g in the center of the shaft, which corresponds to 1.94 pounds.
- Measure the curvature of the barrel as a result of the weight you have just applied. The vertical distance between the shaft and the horizontal drawn between the two support points expressed in 1/1000th of an inch corresponds to the shaft spine.
In short, since the arrow is an important element in archery, the choice of the spine should not be made lightly, because it directly affects your shots. Therefore, it is always recommended to use the chart to choose it correctly.