What Is Balance Point?

Balance Point: definition

Also called: bolt balance point, arrow balance point, center of balance

The balance point is the place along a bolt where its weight is evenly split, so it rests level on a narrow support. Because the tip, insert and shaft wall sit forward of the vanes and nock, the balance point of a normal bolt is ahead of its midpoint.

You find it with the bolt fully built: the field point or broadhead you will actually shoot, the insert and the nock all fitted. Rest the bolt across a knife edge or the thin edge of a ruler and slide it until it stays level. Mark that spot and measure the distance from the nock end. Some guides measure from the nock throat (the bottom of the string groove) instead, so note which convention you used.

On its own, the balance point is just a measurement. Its main use is feeding the FOC calculation, which compares the balance point with the bolt's midpoint and turns the difference into a percentage of length.

Why Balance Point matters

The balance point is the raw number behind FOC, so measuring it accurately is what makes any FOC figure meaningful. A mistake of a quarter inch on a 20-inch bolt shifts the FOC result by more than a percentage point. The FOC calculator does the arithmetic once you have a careful measurement.

It also shows you exactly how a change affects balance. Swapping a 100-grain tip for a 150-grain tip, or adding a lighted nock, moves the balance point forward or back, and measuring before and after tells you by how much instead of guessing.

How to read it on a spec sheet

• Makers seldom publish a balance point. If they do, check which tip weight and nock it assumes.
• Check whether a quoted figure is measured from the nock end or the nock throat.
• Read a balance point together with overall bolt length. The same distance means different FOC on bolts of different length.
• If a listing gives FOC only, you can work back to the balance point with the formula on the FOC page.

Common mistakes

• Measuring with the tip removed. The balance point must be taken with the final tip installed.
• Measuring from the front of the bolt instead of the nock end.
• Balancing on a wide support such as a finger, which hides small differences.
• Mixing conventions, measuring length to the nock throat but the balance point from the nock end.
• Measuring one bolt and assuming every bolt in the set is the same. Check a few.

Find the balance point at home

1. Build the bolt exactly as you will shoot it, with the tip, insert and nock fitted.
2. Set up a narrow edge, such as the back of a table knife or a thin ruler on its edge.
3. Lay the bolt across the edge and slide it slowly until it rests level.
4. Mark the point with a pencil or a small piece of tape.
5. Measure from the nock end (or the nock throat, if that is your convention) to the mark and write it down.
6. Enter the measurement and overall length into the FOC calculator, and repeat for each tip weight you are considering.

See it in our reviews

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