This article needs additional citations for verification . (May 2012) (Learn how and when to remove this template message) |
The bit shank is the side piece or cheekpiece of a curb bit, part of the bridle, used when riding on horses. The bit shank allows leverage to be added to the pressure of the rider's hands 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 reins 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 snaffle bits have no shanks, instead they have a single bit ring.
Bits that have shanks coming off the mouthpiece create leverage 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.
The term shank is generally used interchangeably with the term "cheek" to describe the entire sidepiece of the bit, but shank also may refer just to the lever arm, the portion of the bit that extends from the mouthpiece to the rein ring. The purchase of the bit is the upper portion of the cheek that extends from the mouthpiece to the headstall rings. All shanks have a rein ring at the bottom for the curb rein and a cheek ring at the top to attach the headstall. Some shanks may also add rings or slots to attach a snaffle rein at the mouthpiece, allowing the bit to be used with two sets of reins, making it a pelham 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-style 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 lariat, and can limit excessive motion in a loose-jawed shank.
The length of the shank determines the degree of leverage put on the horse's head and mouth. The leverage ratio for a typical curb bit is 1:4 (where the ratio of upper and lower cheek is 1:3), in that one ounce of pressure by the rider will result in four ounces of pressure on the mouth of the horse. Overall cheek length, from the top of the cheek ring to the bottom of the rein ring, usually cannot exceed 8½ inches for most western horse show disciplines. In Dressage the length of the lever arm portion of the cheek cannot exceed 10 cm. Cheek sizes vary from the Tom Thumb (about 4½ inches long) to bits that exceed the 8½ inch "show legal" maximum cheek length.
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.
Shanks come in a variety of types, which may affect the action of the bit. Some shanks are loose-jawed, meaning they swivel at the point where the mouthpiece attaches to the shank. Others have a fixed shank that does not move. Some shanks have a loose, rotating ring for rein attachment, others have a solid, fixed ring molded into the shank itself.
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 Vaquero tradition generally use a curb bit with straighter shanks. Those that have a nose-out head position when working, such as cutting and 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.
The Cyclopaedia of 1728 referred to shanks or cheeks as branches and described them as outlined in the paragraph below. Although the language is archaic, the underlying classicical principles are still applicable today:
Tack is equipment or accessories equipped on horses and other equines in the course of their use as domesticated animals. Saddles, stirrups, bridles, halters, reins, bits, harnesses, martingales, and breastplates are all forms of horse tack. Equipping a horse is often referred to as tacking up. A room to store such equipment, usually near or in a stable, is a tack room.
A bridle is a piece of equipment used to direct a horse. As defined in the Oxford English Dictionary, the "bridle" includes both the headstall that holds a bit that goes in the mouth of a horse, and the reins that are attached to the bit.
Longeing or lungeing is exercising and/or training young or experienced horses on a rein approximately 23 feet long. It is an excellent way of introducing young horses to regular work and teaching them the trust and respect which is the foundation of the relationship with the trainer. It can also be used to good effect to build strength in ridden horses or for rehabilitation after illness or injury. The horse is asked to work on a circle at one end of a longe line, or rein, by a trainer on the ground who guides the horse's movements using rein, whip and voice commands. Longeing is also a critical component of the sport of equestrian vaulting.
A noseband is the part of a horse's bridle that encircles the nose and jaw of the horse. In English riding, where the noseband is separately attached to its own headstall or crownpiece, held independently of the bit, it is often called a cavesson or caveson noseband. In other styles of riding, a simple noseband is sometimes attached directly to the same headstall as the bit.
A pelham bit is a type of bit used when riding a horse. It has elements of both a curb bit and a snaffle bit. In this respect a pelham bit functions similar to a double bridle, and like a double bridle it normally has "double" reins: a set of curb reins and a set of snaffle reins. Because it has a bit shank and can exert curb-style pressure on the horse, it is considered a curb bit. Like all curb bits, a pelham bit has a mouthpiece, shanks with both purchase and lever arms, a ring for rein attachment at the bottom of the shank, and a curb chain. But like a snaffle bit, a pelham bit also has a bit ring on either side of the mouthpiece. Like some curb bits, a pelham bit usually has "loose" shanks - hinged at the mouthpiece in the same way that the rings of a snaffle bit are hinged. When two sets of reins are used, the snaffle rein generally is wider, to help distinguish it from the curb. A "cowboy pelham" is a western style of loose-jawed curb bit with additional rings at the mouthpiece allowing a second set of reins to be added.
A curb chain, or curb strap, is a piece of horse tack required for proper use on any type of curb bit. It is a flat linked chain or flat strap that runs under the chin groove of the horse, between the bit shank's purchase arms. It has a buckle or hook attachment and English designs have a "fly link" in the middle to hold a lip strap. On English bridles the horse is bridled with the curb chain undone on one side, then connected once on the horse. On western bridles, the curb chain is kept buckled to both sides of the bit.
A snaffle bit is the most common type of bit used while riding horses. It consists of a bit mouthpiece with a ring on either side and acts with direct pressure. A bridle utilizing only a snaffle bit is often called a "snaffle bridle", particularly in the English riding disciplines. A bridle that carries two bits, a curb bit and a snaffle, or "bradoon", is called a double bridle.
A Kimblewick, Kimberwicke or Kimberwick is a type of bit used on a horse, and named after the English town of Kimblewick where it was first made. The bit has bit shanks, D-shaped rings, and a curb chain. Due to its shanks, it is regarded as a type of curb bit. The curb action is minimal to mild, however, because the shanks have short purchase arms and no lever arms. Some variations increase the curb action. A Kimblewick is used with one set of reins.
A curb bit is a type of bit used for riding horses that uses lever action. It includes the pelham bit and the Weymouth curb along with the traditional "curb bit" used mainly by Western riders.
A double bridle, also called a full bridle or Weymouth bridle, is a bridle that has two bits and four reins. One bit is the bradoon, is a modified snaffle bit that is smaller in diameter and has smaller bit rings than a traditional snaffle, and it is adjusted so that it sits above and behind the other bit, a curb bit. Another term for this combination of curb and snaffle bit is a "bit and bradoon", where the word "bit" in this particular context refers to the curb.
The gag bit is a type of bit for a horse. Because the cheek piece and reins attach to different rings there is leverage action. Severity of leverage action depends on where the reins attach. For example, in a Dutch Gag, the further the rein attachment from the mouthpiece the greater the leverage. The gag bit is related to a Pelham bit and a double bridle but the gag bit has no curb strap.
A martingale is any of several designs of tack that are used on horses to control head carriage. Martingales may be seen in a wide variety of equestrian disciplines, both riding and driving. Rules for their use vary widely; in some disciplines they are never used, others allow them for schooling but not in judged performance, and some organizations allow certain designs in competition.
Reins are items of horse tack, used to direct a horse or other animal used for riding. They are long straps that can be made of leather, nylon, metal, or other materials, and attach to a bridle via either its bit or its noseband.
A hackamore is a type of animal headgear which does not have a bit. Instead, it has a special type of noseband that works on pressure points on the face, nose, and chin. It is most commonly associated with certain styles of riding horses.
Draw reins and running reins are pieces of riding equipment used for training that use the mechanical advantage of a 'single movable pulley' to cause the horse to bring its head down and inward. While a regular rein is the strap that attaches to the bit and is held by the rider, these types of reins slide through the bit ring, adding leverage to the rider's hands and arms, allowing the rider to force the horse's head into a desired position.
The bit ring is the ring on the side of a horse's bit, particularly on a snaffle bit. It is used as a point of attachment for the cheekpieces of the bridle and for the reins. It also has an effect on the action of the bit. Therefore, the design of the ring is something to consider when choosing a bit for a horse, even though the bit mouthpiece generally has a greater effect than the ring.
The mouthpiece is the part of a horse's bit that goes into the mouth of a horse, resting on the bars of the mouth in the sensitive interdental space where there are no teeth. The mouthpiece is possibly the most important determinant in the severity and action of the bit. Some mouthpieces are not allowed in dressage competition.
The bit is an important item of a horse's tack. It usually refers to the assembly of components that contacts and controls the horses mouth, and includes the shanks, rings, cheekpads and mullen, all described here below, but it also sometimes simply refers to the mullen, the piece that fits inside the horses mouth. The mullen extends across the horses mouth and rests on the bars, the region between the incisors and molars where there are no teeth. The bit is located on the horse's head by the headstall, and which has itself several components to allow the most comfortable adjustment of bit location and control.
A bosal is a type of noseband used on the classic hackamore of the vaquero tradition. It is usually made of braided rawhide and is fitted to the horse in a manner that allows it to rest quietly until the rider uses the reins to give a signal. It acts upon the horse's nose and jaw. Though seen in both the "Texas" and the "California" cowboy traditions, it is most closely associated with the "California" style of western riding. Sometimes the term bosal is used to describe the entire classic hackamore or jaquima. Technically, however, the term refers only to the noseband portion of the equipment.
A bitless bridle is a general term describing a wide range of headgear for horses or other animals that controls the animal without using a bit. Direction control may also be via a noseband or cavesson, if one is used. The term hackamore is the most historically accurate word for most common forms of bitless headgear. However, some modern bitless designs of horse headgear lack the heavy noseband of a true hackamore and instead use straps that tighten around a horse's head to apply pressure in various ways. These are often specifically patented and marketed as "bitless bridles", usually referencing a particular type of headgear known as the cross-under, though other designs are sometimes also given similar names.