Overspine is a term used in archery to describe a situation where the arrow shaft is too stiff for the bow's draw weight and the archer's shooting style. It occurs when the arrow's spine, or its flexibility, is not matched properly to the bow's draw weight and the archer's shooting technique.
There are several causes of overspine, including:
The most common cause of overspine is using arrows that are too stiff for the bow's draw weight. This can happen when the archer uses arrows that are too short or too light, or when the bow's draw weight is increased beyond what the arrows can handle.
Overspine can also occur if the archer has a very aggressive shooting style that causes the bow to flex more than it should. This can happen if the archer "snaps" the bowstring too quickly or if they grip the bow too tightly.
Environmental factors such as wind and temperature can also cause overspine. For example, if the wind is blowing in the direction of the arrow, it can cause the arrow to fly to the left of the target, even if the arrow is properly spined.
Overspine can have several negative effects on an archer's shooting performance, including:
The most noticeable effect of overspine is that it causes the arrow to fly to the left of the target (for a right-handed archer) as it leaves the bow. This happens because the stiff arrow resists the bending of the bow.
Overspine can also cause the arrow to "porpoise" or "fish-tail" in mid-flight, making it more difficult to hit the target accurately. This happens because the stiff arrow doesn't flex properly as it travels through the air.
Finally, overspine can cause the arrow to land too low on the target, as the arrow's stiffness causes it to drop more quickly than a properly-spined arrow.
To prevent overspine, it is important to take several factors into account:
Choosing arrows with the correct spine rating is critical to preventing overspine. This involves considering factors such as the arrow's length, weight, and material, as well as the bow's draw weight.
Proper bow tuning is also essential to preventing overspine. This involves adjusting the bow's draw weight and other factors to ensure that it is properly matched to the arrows being used.
Finally, shooting with proper form and technique is crucial to preventing overspine. This includes using a smooth release, gripping the bow properly, and maintaining proper alignment throughout the shot.