How To Spine Index Arrows In Water? [The Easiest Method]




At the adult age, I was very mindful to participate in a competition held in our village. My grandfather asked me, if you are interested in winning, then index your arrow spine. 

I asked him Why it is important & how to spine index arrows in water at home. He said-

How To Spine Index Arrows In Water

Spine Index Arrows In Water

  • Fill your water with soapy water, take your arrows, and ensure that the nock is on both ends of the arrow.
  • Now, put the arrow in the tub and turn it a few times.
  • I observed the top part of it in the water, and it is the stiffest part of the spine.

Wait, there is more to share! If you are interested in knowing more about the arrow spine index and how to calculate spine number, follow along then!

Key Point

  • The spine index arrow refers to the spine number on each arrow shaft that helps to improve accuracy and consistency in flight.
  • It is a method to determine your stiffer or flexible side of the arrow.
  • The key limitation of this method is that it can show the stiffer side but can’t provide the exact spine number.

What Do Spine Index Arrows Mean?

Spine index arrows mean you will find the spine number on each shaft of your arrow, and the arrow building the same. Generally, spine are two types such as static and dynamic spine.

What Do Spine Index Arrows Mean

As a result, when the arrow is released from the bow, they all leave the bow the same. These are also known as the determiners of your arrows, which are stiffer spine or weaker.

But why is the arrow spine index done? 

The spine index is done to ensure the arrows have the same stiffness and bend the same way when they are shot. But what is the benefit, right? 

The spine index helps to enhance accuracy and consistency during arrow flight. It greatly impacts the effect of the archer’s paradox. As a result, you will get improved overall performance of the arrow.

When Is The Spine Index Needed?

If you are a novice archer, it is normal to raise curiosity to know when a spine index is needed. Here is the fact-

When Is The Spine Index Needed

Haven’t you understood? Here is an example,

Imagine you have a 300-spine arrow, and this means that it can be bent 0.3 inches when you put a weight on it. 

You have to mark the stiffer and more flexible sides of the arrow. Then, you can easily align the mark with your bow. As a result, it will provide you with a straight flight and more accuracy during flight.

How To Spine Index Arrows In Water?

Do you know how to spine index arrows in water float testing?  Don’t be panicked! It is a straightforward method to find your spine. Let’s see how I usually do it at home:

  • First of all, take a container. You can also use your bathtub and then fill it with water.
  • Then, to minimize the surface tension of the arrow, take soapy water. I am sure that it will help your arrow to turn better.
  • Take your arrow and make sure the nock is opposite. Put a nock on both ends of the arrow.
  • Now, put the arrow in your tub and turn it a few times.
  • Make sure that there is enough water to submerge the water to the bottom.
  • Focus carefully on turning. After a few times, it will stop turning. Observe which of the arrows is on top. 
  • The top side is the stiffest part of the spine. Mark it with a sticker.
  • Repeat it for all the arrows that you want to spine index.

It will help you to improve your accuracy and consistency and nock tuning during flight. Every time I suggest this easiest method, who asks me, “How to spine index arrows in water for archery?. This will also provide you with better shaft tuning results.

How To Find Your Arrow Spine?

So, how do you find the spine of an arrow? Don’t worry! I will explain it as a simpler way for you to find the correct arrow spine. To determine the arrow spine, you have to consider some things that will help you to find the arrow spine easily. Here is the factors:

How To Find Your Arrow Spine

Draw Length

Well, then , how do you find the arrow spine index?In order to find the correct spine, it is essential to find your draw length first. But how will you determine your draw length, right?

You can measure it from your local archery shop. If there is an emergency, you can determine it at home quickly. Just follow these steps:

  • First of all, measure your arm span length.
  • Then divide it by 2.5, and this is your draw length.

Are you confused about how do you calculate arrow spine?? Let’s get clear with an example: 

If your arm span is 70 inches, then your draw length is 70/2.5.

Arrow length

Now, it’s your turn to determine the arrow length. Once you have got your draw length, just add 1 to 2 inches to it. This is your arrow length.

Isn’t it clear yet? Let’s be clear with our previous draw length.

For 28 inches draw length, add 1 to 2 inches. So, 29 to 30 inches is your suggested arrow length. This is just the general rule of thumb.

Draw Weight

To find the correct arrow spine, draw weight is another essential factor. You can determine it easily with a scale at your local archery shop. They are extremely easy to use and reasonably priced.

I would strongly advise getting a digital scale if you plan to make any adjustments or tuning at home because it will ultimately save you time and money. Be careful about measuring your draw weight because it greatly affects the arrow spine. Don’t forget to measure the weight of your type of arrow tip according to arrow type.

Use An Arrow Spine Chart

Once you have determined your draw weight, draw length, arrow length, and tip weight, you are now on the main track to determine your arrow spine. 

Now, use an arrow spine chart. You will find the above factor in the spine chart. To use these charts, just take your arrow tip’s weight and draw weight with the arrow length.

Then, where these three numbers meet on the chart, it will show you the correct arrow spine. You can also find your arrow spine by using an arrow spine calculator.

Limitations Or Considerations When Using Water To Spine Index Arrow

A spine index arrow in water is a method to determine the stiffness side of the arrow. In general, it helps to align your arrow with your fletching and bow.

It plays a crucial role in archery performance because it increases your arrow grouping and consistency.

Here are some limitations and considerations as follows:

  • This method can help you determine the stiffness of the arrow, but it can’t provide the exact spine number of your arrow. For spine testing, you will need a spine tester or a spine chart.
  • This method doesn’t work well for all types of arrows. There are various types of arrows available, such as carbon arrows, aluminum arrows, wooden shaft arrows, etc. For example, carbon express arrows don’t show the stiffer side because of their uniform arrow weight distribution.
  • These can be significantly affected by your container size, water temperature, and also the presence of air bubbles. As a result, it can lead to bad arrows & inaccurate results.
  • If your arrow is more glued, the glue can detach from it and affect the weight and balance of the arrow.

How To Test Your Spine Arrows?

So, how to spine arrows?  Or, how to calculate arrow spine?  You know that spinning an arrow is the process that helps you to find the stiffness or flexibility of the arrow.

How To Test Your Spine Arrows

You can spine your arrow in two ways, such as using a spine tester or a spine chart. In this section, I will discuss how to test your arrow spine by using a spine tester.

Here is the process:

Frequently Asked Questions( FAQs)

Is My Arriw Spine Too Weak?

Shoot your arrows at a target. If your arrow is too weak, it will cause the shot to be less accurate. An arrow with too much stiffness will favor slightly left, while one with a weak spine will veer right.

Is A 300 Spine Arrow Good?

In general, it is the lower spine number and refers to the stiffer arrows. A 300-spine arrow is suitable for higher draw weights, tip weights, and larger arrow lengths.

What Level Of Expertise Is Required To Perform Water Spine Indexing?

There is no requirement for a high level of expertise to do it. If you have basic knowledge about arrow spine and fletching, you can do it quickly.

Final Thoughts:

Hopefully, you have cleared your confusion about how to spine index arrows in water. It is crucial to do for target competition shooting and hunting. This greatly improves the accuracy and consistency of the flight. Keep in mind the limitations also. That’s all for today! Stay with archery magic to get more like this.

Bob Magic

Written by

Bob Magic

Meet Bob Magic, the archery maestro. A National Champion, “Coach of the Year,” and gold medalist. Bob simplifies archery, ensuring your bullseye success. Whether you’re a newbie or a pro, let Bob’s magic guide your arrow.

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