Making Sense of Arrow Spines: The Ultimate Guide
In the world of archery, most people have heard of a recurve bow or compound bow. But what about an arrow spine? It may sound like a complicated topic but this article will break down everything you need to know about arrow spines and how they affect your shot with a recurve bow.
What is an arrow spine?
An arrow spine is the stiffness of an arrow. It’s this stiffness that determines how well your arrows fly through the air and hit their target. Arrow spine is a measurement of how much an arrow bends.
The term “spine” in regards to archery has been around for quite some time, with it first being used in 1858. It makes sense when you think about it; the arrow spine is the “spine” of an arrow, or what supports it.
Why is Arrow Spines so Important?
Arrow spines are important because they determine how well your arrows fly. It all comes down to the arrow spine chart . This is a tool that you can use, along with proper arrow information , to find an arrow that matches up with what you need for hunting or target practice.
Why does the arrow bend?
Arrows bend due to the tension that is placed on them. The more force you apply, the more your arrow will flex and turn into an S shape when released from a bowstring.
The spine of an arrow can range in stiffness depending on its purpose. A hunting bow may have arrows with different spines for each type of game it hunts. The arrow spine will typically be matched to the weight of an animal, for example a deer is heavier than a duck and therefore needs more force behind it when it hits.
In short, the nock moves before the point does, so the arrow is forced to bend. The amount it bends depends on how fast the bow is and how long it takes for the arrow to reach full speed.
Let’s imagine a very simple set up. When you release the string it accelerates. Suppose that the string accelerates to full speed instantaneously. Then the nock must also go through the same acceleration. If the arrow was perfectly stiff, that is had a spine rating of 0, then the point would also go through the same acceleration. Of course, our arrows are not perfectly stiff.
Instead, the shaft of the arrow absorbs some of that force applied upon release. So, the force must travel down the shaft of the arrow, called an impulse. That delay in the force reaching the point of the arrow means that, just for a brief moment, the nock is moving at full speed while the point of the arrow is still stationary. The distance between nock and point is therefore less than the length of the arrow so the arrow shaft must bend.
Where does it bend?
Arrow spine is the bending of an arrow as it leaves a bow. It’s important to know that as your arrows leave your bow, they are still spinning and flexing.
The length of time that an arrow exists inside the “tunnel” will determine how much force there is applied to it by each part of the tunnel (the string, the shelf and your fingers). It’s this force that will affect how much it bends.
The arrow spine chart recurve shows that different arrows have different spines based on their length and weight.
Arrow spine is the stiffness of an arrow, which determines how well it flies through the air to hit its target. It’s important to know that as your arrows leave your bow, they are still spinning and flexing until fully released from the string.
The amount it bends depends on how fast your bow is and the length of time it takes for the arrow to reach full speed. For a bow shot from the fingers, the arrow bends horizontally, ensuring clearance around the rest and riser. For a bow shot from a release aid the arrow bends vertically, ensuring clearance over the arrow rest. The bend in an arrow causes an oscillation around two points that remain still (in relation to where the arrow is travelling) called nodes. Where those nodes are is important.
How to Calculate Arrow Spine?
Archery is a sport that requires expertise and skill. Often, arrows are fine-tuned for the bow by adjusting the spine to make them fly further. In order to calculate your spine, you can use the following formula: 7.2/(L/d) = spine . For example, if your bow has a length of 45 inches and a draw weight of 40 pounds, the spine is 0.24.
For the calculation the pull weight is given in pounds and the arrow length in inches. You usually find these details when buying a bow and arrow, so you don’t have to convert them. You can also use an arrow spine chart when calculating your spine value.
Gold Tip Arrows Spine Chart
Two Different Types of Arrow Spine
Before we get into how arrow spines affect your bowhunting experience, it’s important to understand that there are two different types of spine.
First off is the front or back (positive) spine, which determines where on the arrow you place weight for stabilizing and balancing. This type of spine helps decrease wobble while in motion when you release the arrow.
Secondly, there is the side (negative) spine which determines how well your arrows shoot straight while in flight. This type of spine helps decrease wobble while shooting an arrow so that you can have a more accurate shot at what you are aiming for.
A Complete Guide to Arrow Spine
Choosing the correct arrow spine for your bow can be incredibly confusing and seems like a mystery that you may never get your head around. There are a lot of factors that affect correct arrow spine (like draw length but even parts of your technique like consistency, tension and execution) so, it is perfectly reasonable to feel that way. A lot of top archers find an arrow set up that works for them and stick with it, not necessarily understanding why that’s the set up that worked.
Before you start looking for arrow spines, it’s important to know what your goals are. It is really easy to get lost in the technicalities of how things work and forget why we shoot arrows in the first place (to kill stuff).
Your Goals will help you understand which type of Arrow Spine you should be using; if your goal is to get close and shoot accurately, you will not be using the arrow spine for 300 yard shots.
Draw Length – Compound
The draw length of your bow is the first thing you will need to know. It’s easy enough, just pull back until it reaches one third of its total distance (it should be marked on your riser). This means that if you want 300 fps arrow speed, your overall draw length must be at least ten inches longer than what it measures.
Draw Length – Recurve
To measure your draw length with a recurve bow, you need to know that the standard is 28 inches from where the arrow attaches on one side of the riser and up along the limb until it touches the other attachment point. Once again this needs to be at least ten inches more than the overall arrow speed.
Practice Makes Permanent
Once you’ve got your draw length, it’s time to practice. You will need to make sure that everything is as consistent as possible and the only way of doing this (for now) is by practicing over and over again until you can do it without thinking about it.
You should always shoot with a good stance; one where your legs are shoulder width apart, you have a level upper body with the weight evenly distributed on both feet. Your bow arm should be bent slightly and not fully extended unless required for an arrow that’s 300 yards plus away from you.
Arrow Spine Chart Recurve
The Arrow spine chart recurve is here to help you find the arrow spine that best suits your archery equipment. This chart is a great resource for finding what’s suitable, but it can be difficult to understand if you don’t have a basic knowledge of how they work- so we’ve given you some advice on this below:
300 FPS Arrow Spine 300 fps means an arrow speed of 300 feet per second. 300 is the highest arrow spine that you should be using when hunting anything larger than a raccoon, or if you are in an area where there are bears present.
Effort or Effortless?
There is certainly merit to be given to the idea that effort reaps reward and laziness gets you nowhere. In a sport such as archery it is important to put that effort in where it is most valuable.
Effort in training is vital, but not discussed in this article. This article covers the effort required to shoot an arrow. In short, too much effort makes the shot tiring, you’ll fatigue earlier and struggle to maintain consistency, too little effort makes the shot weak so the bow will react differently to each shot.
Execution is Key
Execution is vital to the accuracy of your shot. If you are inconsistent, or executing a certain way that makes it difficult for you to maintain good form then this will affect arrow spine choice because consistency is key .
This can be one large factor in determining which arrow spines work best with your bow and technique as there could potentially be several factors affecting the arrow spine you choose to use.
To ensure no vertical force is placed on the arrow you must put tension in your rhomboid at the right height. If you use your lower rhomboid too much you will create a downward force through your release motion as well as introducing an upward force on your front shoulder that will cause your arrow to go high. Similarly, if you have too much bias to your upper rhomboid your arrow will tend to fly low.
Balancing this pull on your release rhomboid against your bow-side rhomboid is what gives you stability in your aiming. We will cover this in a different article, but the important part here is that you wish to find this balance at the moment of execution. By doing so you ensure your bow is at its steadiest as the shot releases, again reducing any unhelpful lateral forces on the arrow as the bow itself isn’t moving. This is also helpful in the final key factor of a well-executed shot.
There are two key take-aways: Alignment and balanced back tension to get the shot to go off so that your hand moves directly away from the path of the arrow, and, more than anything, trust your shot and execute with confidence.
With so many arrows on the market, it can be hard to choose which arrow spine is best for your bow. This ultimate guide will break down what you need to know about all of them and help you make an informed decision that’s right for you. We hope this has been helpful! If there are any questions or anything else we can do please let us know by leaving a comment below. Happy shooting!