How do you calculate arrow spine weight?

How do you calculate arrow spine weight?

Static spine is how much an arrow reacts when a 1.94 lb. weight is hung from the center of the arrow. To calculate this, arrows must be 29” long and supported at two points 28” apart. The number of inches the arrow bends multiplied by 1,000 is the arrow’s spine.

What does 250 spine mean in Arrows?

The spine rating of an arrow is simply a measurement of its stiffness. The same Easton arrow comes in a variety of stiffness: the lower the number, the stiffer the arrow. For example, a 330 arrow is stiffer than a 500 spine arrow.

How much does a 340 spine arrow weight?

That’s why Gold Tip recommends a 400 spine for a 27-inch arrow with a 100-grain point shot from a 60-pound bow, but also recommends a 340-spine arrow if its length and draw weight stay the same, but its point weighs 150 grains.

What does 340 arrow mean?

As with combination arrows, a smaller number means the arrow has a stiffer spine. Therefore, a value of 340 indicates a stiffer and heavier spine while a value of 500 indicates the lightest and most flexible spine.

How long should my arrows be with a 28 inch draw?

around 27 inches
If you’re a 28-inch draw length and want an arrow that ends at the front of the riser, your arrow length would be around 27 inches. However, your arrow length can be longer if you need to weaken the spine of your arrow. For safety reasons, your arrows shouldn’t be cut too short.

How to calculate arrow weight and why?

Grains Per Inch. The GPI number does not include the nock,insert,point or fletchings.

Grains Per Pound. A light arrow has a finished GPP of 5 to 6.5 grains for each pound of draw weight.

Front of Center. The arrow’s point is heavier than its fletchings.

Light vs. Heavy Arrows.

How to choose the correct arrow spine?

You need to know your peak weight. A peak weight is the maximum amount of weight that you can pull when drawing your bow.

You need to know what your ideal arrow length is. The longer the arrow shaft,the more it will flex.

You need to know the point weight of your arrow. The heavier the point,the more it will flex.

What size Arrow to use?

Once you’ve determined your draw length, simply add 1 to 2 inches to that, and this will be your ideal arrow length. So if your draw length is 28″, you should be using arrows that are between 29 and 30 inches long.

How much does an arrow weigh?

A mid-weight arrow weighs between 6 and 8 grains per pound of draw force (420 to 560 grains for a 70-pound bow) and a heavy arrow weight is anything weighing over 8 grains per pound of draw force (over 560 grains).