Understanding Bits for Horses

Understanding how a bit works in the horse’s mouth will help you select the most appropriate bit for the job and appreciate the craftsmanship of well balanced and constructed bits.

Lesson Instructions

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Learning Objectives

Learning Objectives

Learning objectives of this module.

  1. Learn how to categorize bits.
  2. Learn about variation in bit construction.
  3. How to introduce training principles related to bit use.



A bit – the part of the bridle that is inserted into a horse’s mouth – enables a rider to cue a horse by placing pressure in and around the horse’s mouth. This pressure is used to control the horse’s speed and direction of movement. Bit selection is influenced by a variety of factors, including the style of riding and traditional bit use, the rider’s ability, the level of the horse’s training, and the intended use of the horse.

Specific riding disciplines use one type of bit more than another. For example, stock seat horses are ridden mostly with curb bits, with riders placing one hand on the reins and no rein contact on the horse’s mouth unless applying a specific cue. Conversely, hunt seat horses are ridden mostly with ring snaffles and guided with two hands on the reins and continual light rein contact with the horse’s mouth. Bit selection will also vary because of differences in the abilities of horses and riders. Inexperienced or incorrectly trained horses may be confused and respond adversely to the type or intensity of pressure applied by some bits. Similarly, some riders may apply inappropriate levels of pressure with some bits, or they may apply pressure at the incorrect times.

The objective of this module is to assist the inexperienced rider in the selection of bits. Identifying differences in bit construction and understanding some of the important principles of bit use will provide an educated basis for selecting bits. Readers are encouraged to continue their education by receiving hands-on instruction from experienced professionals and by reading and viewing the many resource materials that have been developed on training horses. By doing so, riders will gain a better understanding of the training process and how bit use and selection can assist in achieving their riding goals.


Categorizing Bits

Categorizing Bits

Bits function by placing pressure on and around a horse’s mouth. That pressure can be on the bridge of the nose, under the chin, corners of the mouth, tongue, bars, palate, or poll. Bits can be categorized into those placing pressure primarily on the nose and chin when rein pressure is applied, those working primarily on the mouth with direct pressure from the reins, and those working primarily on the mouth and curb with leverage pressure from the reins.


A hackamore is designed to exert pressure on the bridge of the nose and under the chin of the horse’s head. The headstall of a hackamore also applies pressure to the horse’s head behind the ears (poll). The bosal on the right is a breaking hackamore made of a headstall and bosal, or noseband. Bosal hackamores are used in training young horses in the stock seat discipline. Bosals are used to a lesser extent with older horses. There are several variations to the basic bosal, such as a side pull hackamore that places the rein attachment to the side of the horse’s face, thus lessening chin pressure and increasing lateral pull.

Mechanical hackamore

Mechanical hackamores are used to enforce a stop or a slowing action in activities such as roping and speed events. Mechanical hackamores limit lateral pull, even when single rein cues are applied. They are most effectively used on horses with previous training rather than as a beginning bridle. One variation of a mechanical hackamore is the addition of a mouthpiece to increase pressure inside the mouth when rein pressure is applied.

Snaffle Bits

A snaffle bit, also called a ring snaffle, is made up of a mouthpiece and rings. Snaffle bit mouthpieces are most commonly jointed in the middle. Consequently, curb bits with jointed mouthpieces may also be termed a snaffle, although the bits actually work by leverage or curb pressure. True snaffles are constructed so the bridle headstall and reins are attached to rings positioned on the outside of the horse’s mouth. Snaffles apply rein pressure directly to the mouthpiece, and the amount of rein pressure applied to contact points of the mouth is equal to the degree of pressure applied by the reins. Snaffle bits place pressure on the tongue, the corners of the mouth, and the bars of the mouth.

The picture in the right is an O-ring snaffle. Ring snaffles apply direct pressure from the reins to the horse’s mouth. Most ring snaffles have jointed mouthpieces to intensify the pressure on the corners of the horse’s mouth. This enhances the ability to pull laterally, thus directly guiding movement by repositioning the horse’s head to the direction of desired movement. Pressure is intensified by using multiple mouthpieces, small diameter mouthpieces, or rolling or twisting mouthpieces.

Inexperienced horses are taught to respond from a direct pull of the reins. Young or inexperienced horses are expected to require frequent reinforcements following the horse’s response to an initial cue. Snaffles apply a simple type of direct pressure when used correctly and are mild enough to use with frequent reinforcements. English style riding allows for continual snaffle use throughout the use of the horse, as these horses are ridden with a constant, light contact. Most Western showing requires that older horses perform in curb bits. Even so, snaffles are commonly used as a training tool throughout the life of horses ridden Western style because of the advantages of snaffle action when applying frequent reinforcements or when conducting riding activities that require constant slight mouth pressure.

Variations in Bit Construction

Curb Bit

A curb bit is constructed with a mouthpiece and shanks. The headstall is attached to upper shanks and the reins are attached to lower shanks of a curb bit. A curb bit applies leverage pressure and, as such, increases the amount of pressure from the reins to contact points in and around the horse’s mouth. In general, curbs are designed to be used with no rein contact unless the rider is applying a specific cue.

When reins are pulled, the action of the mouthpiece and curbstrap tighten on various locations in and around a horse’s mouth. Curb bit construction is modified to apply varying amounts of pressure on the tongue, lips, bars, roof of the mouth, and, by way of the chinstrap and headstall, under the chin and over the poll on the horse’s head.

The bit on the right is commonly identified as a grazing bit. Curbs are used primarily to slow or stop horses with pressure created by leverage and to guide horses by using a neck rein cue. A neck rein is a slight rein cue applied to the neck of the horse more so than to the mouth. The neck rein does not apply an appreciable amount of pressure to the horse’s head or neck and does not forcibly turn the mouth to the direction of desired movement. Rather, correct response from a neck rein occurs as a learned response from reinforcements with direct pull or pressure on the horse’s mouth. Curbs are used on horses trained previously with snaffles to respond to direct and neck rein cues. Curbs with longer lower shanks in relation to upper shank length increase pressure by increasing the leverage of pull. Pressure is intensified on specific pressure points by variations in the mouthpiece design.

Mouthpiece variations common to Snaffles and Curbs

Bits are constructed to vary the location, intensity, and type of rein pressure. Hackamores vary in the flexibility and size of the bosal, or noseband, and the amount of release, or open space between the noseband and the horse’s nose and chin in the absence of rein pressure. Snaffles vary in the type of material, shape, diameter, texture, and hinges in the mouthpiece, the attachment of the mouthpiece to the rings, and the size and shape of the rings. Curb bits share similar variations, but they are more involved. The attachment, length, and shape of the shanks, the angle of the mouthpiece in relation to the shanks, the amount of release allowed by the curb strap, and the shape and angle of the port and bars of the mouthpiece affect the amount and distribution of rein pressure from curb bits.

Mouthpiece variations common to Snaffles and Curbs

Most bits are made of steel, iron, or aluminum. Some have mouthpieces made of or inlayed with copper, as one school of thought suggests that combining copper with steel or iron enhances salivation. Some mouthpieces are covered with rubber. Curb bit shanks and snaffle rings may be flattened or round and engraved or inlayed with precious metals (silver or gold) for aesthetic value.

Pressure is directed to specific pressure points by variations in the mouthpiece design. Mouthpiece diameter may be tapered to the center and typically varies from 5/16 inch to 3/4 inch, although there are smaller and larger sizes. The smaller the diameter of the mouthpiece, the smaller the contact in the horse’s mouth. And the smaller the contact area, the more intense the pressure a horse feels from a given amount of pressure from the reins. Most mouthpieces are smooth and rounded. Some mouthpieces are twisted, rolled, or flattened to cause variations in intensity of pressure.

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Variations of Snaffles Ring Construction

The rings on the outer portion of a snaffle bit function to position the mouthpiece and allow attachment of the headstall and reins. Variations in ring diameter and shape influence the location and intensity of rein pressure. Most commonly, rings are full- or half-circular in shape and are usually 2 inches to 4 inches in diameter. Smaller ring diameters may allow the mouthpiece to be misaligned with the mouth when using a single rein or lateral pull. Cheek pieces may project beneath or both above and beneath the ring and run perpendicular to the muzzle of the horse.


Variations of Curb Bit Construction

The mouthpiece port is the raised portion on the center of solid, or non-hinged, mouthpieces. Some hinged mouthpieces also have ports. The port places pressure along the tongue and, if high enough, the roof of the mouth. Ports with 2 1/2 inches or more of elevation can apply pressure on the upper palate and, because of the sensitivity of this area, should not be used on inexperienced horses or by inexperienced riders. Wider port widths allow for less pressure on the tongue. Port shapes vary, including rounded, flattened, rolled, and covered. The top of the port may be flattened backward to heighten pressure on the tongue in the absence of rein pressure and to alter bit balance. Port heights and widths vary to allow for differences in the amount of tongue relief and pressure on the upper palate.

The mouthpiece-shank junction may be welded solid or be attached with a sleeve or hinge that allows some flexibility. Bits that are loose-shanked, sleeved, or hinged at the mouthpiece-shank junction allow for the initial part of the rein pressure to be exerted more gradually. This slight difference is termed signal.

Variations of Curb Bit Construction

The placement of the mouthpiece relative to its angle with the shanks will also affect how the mouthpiece lies in the horse’s mouth. As viewed from the side, this angle is created by the position of the port relative to the position of the upper shanks. Mouthpiece placement usually varies from the port and upper shanks being aligned with one another to the port positioned forward of the upper shanks by about 20 to 30 degrees. Altering the placement, weight, and shape of the shanks and mouthpiece affects the pressure exerted on the tongue and bars and the balance of curb bits.

Bits constructed to significantly release pressure when rein pressure is released are termed over-balanced. Bits that maintain pressure without rein pressure are termed balanced or under-balanced. Balance can be determined by laying an unattached bit on your fingers, which are positioned under each end of the mouthpiece. A bit is over-balanced if the lower shanks of the bit hang forward of the mouthpiece and upper shanks. It is under-balanced if the lower shanks hang behind the mouthpiece. Most bits are designed to be over-balanced because they release pressure when not cueing. Balanced bits are used infrequently and, then, only on experienced horses and by experienced riders.

Introducing Training Principles related to Bit Use

Training Principles Related to Bit Use

Bits provide one of the major points of control when riding horses. Knowledge of horse behavior and training principles used to modify behavior must be considered when selecting and using bits. Bitting is a continual process which, through repetitive and step-wise training, teaches horses to accept bits and to properly respond to bit pressure.

The goal of the bitting process is to train the horse to respond to as light a bit pressure as possible to perform a given task. Therefore, rein pressure should be as light as possible when used as a cue or to reinforce a cue. Applying large amounts of rein pressure when cueing a horse for an initial response, will increase the frequency of undesirable responses from the horse and limit his ability to learn additional tasks. Therefore, inexperienced horses should be trained in bits that apply mild, direct pressure instead of bits that intensify pressure or apply large amounts of leverage.


Introducing A Young Horse to Bit and Rein Pressure

Applying single episodes of long-term pressure encourages resistance and avoidance of cues. Application of bit pressure should be short-termed and followed immediately by a release period. If more rein pressure is needed for reinforcement, additional “pull-and-release” pressure should be applied instead of lengthening the duration of the initial cue.

Horses in the beginning stages of training should be accustomed to the bit and taught to respond to rein pressure before being ridden. This can be accomplished with several sessions of bridling the horse with a ring snaffle bit and allowing him to wear the bit for several hours at a time without reins attached. The second objective is to teach the horse to respond to rein pressure. One way to do this is to tie the reins from a snaffle bridle to a bitting harness so small amounts of pressure are applied to the horse’s mouth until the horse responds acceptably by giving in to the rein pressure.

Ground Driving

Another method is ground driving. Ground driving employs the use of long lines attached to a ring snaffle bit. The lines are directed through a bitting harness or saddle to aid in directing the pull from the handler to the horse’s mouth. The handler guides the horse with the lines while positioned several yards behind the horse. Horses can be taught to stop, back up, and guide with direct rein pressure before being ridden for the first time. Ground driving is used with young horses to introduce bit pressure and as a reinforcement aid on older horses. Unless experienced with these methods, readers are encouraged to receive hands-on instruction from knowledgeable people before attempting these or other pre-ride bitting methods.



Bits can be constructed in different ways to assist in training horses for specific tasks. Most of the differences not discussed in this module are intended to increase the severity or intensity of pressure a bit exerts. For example, some bits are designed to be ridden with two sets of reins, one on snaffle rings and one on curb rings. Some bridles actually have two bits, one a snaffle and one a curb. Different materials may be used for the mouthpieces. Some may work concurrently with a noseband attached to a bit with a mouthpiece.

This historical development of modern-day bits is an interesting area of study, as is the process of evaluating the many different types of bits available today. Regardless of personal preferences or aesthetic appeal, most horse experts agree it’s important that bits be functionally correct and that the rider understands how particular bits exert pressure and how a horse should respond. And above all, it’s important to remember that the hands of the rider affects the function of the bit more than a particular construction variation.

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