Product Code Database
The bit shank is the side piece or cheekpiece of a curb bit, part of the bridle, used when equestrianism on . The bit shank allows leverage to be added to the pressure of the rider's riding aids on the bit. Shanks are usually made of metal, may be straight or curved, and may be decorated in some disciplines. The headstall and curb chain or curb strap of the bridle is attached to the top of the shank, and the are attached at the bottom. Shanked curb bits are used in western riding for nearly all adult horses, and are seen in English riding disciplines primarily as part of the double bridle used by advanced dressage riders, and on the hybrid pelham bit that includes a ring for a second rein attached at the bit mouthpiece.
Direct pressure have no shanks, instead they have a single bit ring.
Bits that have shanks coming off the mouthpiece create and place pressure on the poll via the crownpiece of the bridle, to the chin groove via the curb chain, and, especially with a "loose jaw" shank, may also touch the sides of the mouth and jaw. The shank and its leverage action is what defines a curb bit as a curb, regardless of mouthpiece. Though most curb bits have a solid mouthpiece, with or without a port, any bit with shanks and leverage is always a "curb" type bit, even if has a jointed mouthpiece. Shanked bits in the curb family include the Weymouth, which is the curb portion of the double bridle; the pelham bit, a single bit ridden with two sets of reins; and the single-reined curb bit.
Some shanks, especially on the Weymouth, have small rings placed midway down the shank to attach a lip strap, a helpful addition to the bit for preventing a horse from grabbing at the shanks with its lips. Some shanks on western riding bits are "hobbled" together by a metal bar (sometimes called a "slobber bar" because saliva from the horse's mouth can drop onto it) or even a piece of leather, which has the dual effect of keeping anything from getting wrapped around the shank, such as a lasso, and can limit excessive motion in a loose-jawed shank.
The relative ratio between the length of the purchase and the lever arm also affects the amount and type of leverage that is applied to the chin and poll of the horse (producing 1:3 ratio of rein to chin+poll forces in case of the typical curb bit). A long lower shank (lever arm) in relation to the upper shank (purchase) increases the leverage, and thus the pressure, on the curb groove and the bars of the mouth. This design is best suited for a longer-necked horse, as it encourages the horse to both drop its head down and bring its nose in. A somewhat long upper shank in relation to the lower shank increases the pressure on the poll, but does not apply as much pressure on the bars of the mouth. This design is often more helpful on a horse with a short and thick neck, as it encourages the horse to drop its head, but with less pressure to flex the nose in, an act that is physically more difficult for a horse with a thick neck.
Overall, a shorter-shanked bit is usually a milder bit, but also responds quickly when the rider touches the reins. Short shanked bits are usually better for a young horse transitioning from a snaffle to a curb because if the inexperienced horse gets into a place where bit pressure from the rider's hands becomes significant, there is less leverage pressure placed on the horse's head.
However, as the horse becomes more polished in its training, a somewhat longer shanked bit is preferred for its subtlety. Longer shanked bits must rotate back further before applying pressure on the horse's mouth than shorter-shanked bits. Therefore, the horse has more "warning" of a rider's hand movements in a long-shanked bit, allowing it to respond before any significant pressure is applied to its mouth. In this way, a longer shank (up to a point) can allow quieter communication between a well-trained horse and a rider with soft hands, without increasing severity of the mouthpiece.
Any moving parts on a shank that allow slight movement in the shanks before the bit engages provide a "warning" to the horse, allowing it to respond to lighter pressure, thus allowing more subtle communication between horse and rider when on a loose rein or when introducing a young horse to curb pressure.
The cheek-to-shank angle also varies, with some straight up and down, others with the shanks curving backward. Some shanks have a dramatic S-curve. Cheek angle influences the angle at which the bit engages and thus way the horse carries its head. Therefore, the type of shank needs to be considered according to the use of the horse. Horses that maintain a more vertical head position, such as dressage horses and western horses trained in the "straight up" or cowboy tradition generally use a curb bit with straighter shanks. Those that have a nose-out head position when working, such as cutting and team roping horses, more commonly use a more curved shank. Shanks on certain western bits that curve back are sometimes called a "grazing bit." Though a horse should never be allowed to graze in a bridle, the term came from the mistaken notion that the turned-back shank was to allow the horse to eat with a bridle. In reality, the design simply allowed the horse to comfortably travel with its nose well ahead of the vertical. An S curve in a shank does not have a major effect on the angle at which the rein engages, but may alter the balance of the bit at the point the lever arm joins the mouthpiece.
|
|
