Stabiliser (archery)

A bow with long-rod and reverse stabilisers

A long-rod stabiliser holds a weight in front of the bow. It is usually fitted into the centre section in line with the bow arm, or just below the hand position. The addition of this weight moves the centre of gravity of the bow forwards, with two results.

First, "torque" effect (sideways twisting of the bow-hand) movement is reduced. At full draw, the string prevents the bow from twisting, but on release, the bow can turn sideways to some degree, directing the arrow to the left or right.[3] But with the forward centre of gravity, the effect is reduced. Similarly, "topping" (upwards) or "heeling" (downwards) inconsistencies of the bow-hand are reduced.

Second, with actual movement of the bow-hand sideways, up, down, or any combination, because the centre of gravity is in front of the hand, the bow will turn in the opposite direction, to correct, to some degree, the archer's error.

There is also an effect that does not actually give enhanced accuracy or precision, but there are times when this can still be helpful except in the mind of the archer: the pleasing "forward roll" of the bow, as part of the follow-through, with a relaxed bow-hand and forward centre of gravity.

Fitted above and below the bow-hand, normally close to where the limbs meet the centre section, these have similar effects to the single long-rod, but also have a third effect. Because of their positioning, the twin weights also resist rotation instigated by a bow-hand error. If this error were not reduced, left or right shots would occur, because the aiming of the arrow takes gravity into account to gauge the trajectory. Consequently, with perfect aim, if the bow rotates on release, the effect will be the same as not holding the bow vertically, i.e. left or right.

Similarly to the long-rod, a "forward roll" will be induced on release and, in addition, because the twin stabilisers are positioned at the base of the limbs, depending on the rigidity of the mounts, some vibration may be damped, giving a smoother feel to the shot.

Fitted usually below the bow-hand on the centre section, because they point back towards the archer, they bring the Center of Gravity backwards. Consequently, they are typically used in conjunction with a long-rod stabiliser, the long-rod having sufficient turning moment to exceed the negative effect of the reverse weights, and so keep the forward roll of the bow on release, this being generally accepted as a desirable feature. Hence, the forward centre of gravity effect will not be as great, but, because the reverse weight or weights are extended horizontally from the vertical centre section, their effect is to reduce vertical turning caused by bow-hand torque. This is, of course, in addition to any long-rod stabiliser anti-torque effect.

Consider the bow as being potentially on a pivot at the pressure point of the bow-hand. If the archer applies inadvertent pressure off centre of the pressure point, then inadvertent movement of the bow will result, with loss of precision. By careful study of the bow's movement, the appropriate positioning and addition of weight(s) may be tried, to reduce errors, although prevention is better than cure.

Further, various types of mount have been used, to allow some degree of flexure between the bow and the stabiliser weight. Similarly, the weight may be on an extension rod that may flex in itself. The object of the exercise should be kept in mind, and that object is to reduce bow inadvertent movement. Any flexure will allow some movement of the bow, without similar movement of the weight, hence lessening the weight inertia. However, many archers have found an apparent improvement in their precision with the use of flex / mounts. The weight in hand remains unchanged, and so may contribute to steadiness of aim. Also, the flexing gives a "rubbery" feeling, as though the bow wants to remain steady on aim. Consequently, it may be that such effect helps the archer's feeling of confidence on the shot, thereby contributing to precision.