Horse Illustrated Magazine

Whether you’re a seasoned rider or just starting your horsemanship journey, bits are a complex science. It can seem daunting to choose the right one from the wide array of western bits available, but armed with information about the major types and their mechanics, you’ll have an idea of where to start, and which bits to leave on the rack.

A bit’s purpose is to provide a way of effectively communicating with your horse. Bits work in conjunction with a headstall and reins by applying pressure to different parts of the horse’s head: the bars of the mouth, the tongue, the palate (roof of the mouth), the chin, the nose and the poll. Some bits work on several areas at once.

Find out how to choose the right bit for your English horse >>

Bit Severity: It’s Not Just About Size

A big western bit with long shanks and a high port might look like it would be painful for a horse, and it can be, but that is not always the case. The most important factors affecting a bit’s severity are the rider’s experience and the hands wielding the reins.

Jessica Leatherwood, assistant professor of equine studies at Sam Houston University, says a good rider can take a seemingly strong bit and achieve great responsiveness from the horse with a light touch, but a careless hand can make even the mildest bit cause the horse pain. It’s all in how you handle the reins.

“The reins should not be used to support the rider,” says Leatherwood. “The same bit in the hands of beginning riders or those with poor riding skills who use the reins for balance and support may produce vastly different results.”

Bit maker Jim Edwards says the most important part of a bit is the mouthpiece. Any sharp edges from either poor workmanship or the design itself can cause unintentional pain to the horse.

The diameter of the mouthpiece influences severity. A thinner mouthpiece exerts pressure over a smaller area of the tongue and bars of the mouth, concentrating that pressure. And a too-thick mouthpiece can press on the bars and tongue with no room for relief.

The port of the bit also plays a role in its severity. You might think a high cathedral bit is inhumane, and in uneducated hands, that is true. But used properly, a bit with a high port cues the horse long before that port ever touches the horse’s palate, allowing for a quicker response from the horse from very little movement of the reins. Edwards says a ported bit with a smooth transition area is one of the kindest curb bits you can choose for your horse.

“A correctional bit has room for the tongue to get relief,” Edwards says. “As long as the transition is smoothly constructed, without ragged edges or prongs, a bit like this is very comfortable for the horse.”

Contrary to popular belief, a single-joint mouthpiece on a shanked bit can be one of the most severe bits in the tack room. It might seem innocuous, but Edwards says in the wrong hands, the single-joint broken mouthpiece combined with a shank and a curb chain can activate a nutcracker type action on the horse’s mouth, with no room for release from pressure.

“A single-joint mouthpiece was designed for direct pressure,” Edwards said. “When it’s used improperly with a shanked bit, it can scissor on the horse’s mouth and be very painful.”

When the reins are attached to the bit directly, rather than to a shank, pressure from those reins pulls directly on the bit. When attached to the shank, the reins activate indirect pressure onto the mouth through the shank and curb chain, while also putting pressure on the horse’s poll through the headstall.

A long shank will increase leverage. If you pull hard or quickly on a bit with a longer shank, you’ll exert tremendous pressure on the horse. On the other hand, a long shank can mean you’ll cue the horse with a minimum of movement from your hand.

“Shank length, shank straightness, whether or not a bit swivels, the length of purchase (the top part of the shank) and type and width of curb strap all influence severity,” says Leatherwood. “Correct use of your hands is critical in determining the performance of a bit. In most instances, the problems perceived as resulting from not having the correct bit are, in reality, training problems.”

How Do I Choose the Right Bit?

Leatherwood advises looking at your horse’s level of training and your own level of experience when choosing a bit. Inexperienced riders or horses should be equipped with softer, less severe bits for learning without damaging the horse’s mouth.

“It’s important to experiment with bit selection to determine which bit works best for a particular horse and rider combination,” says Leatherwood.

When you purchase a curb bit, it’s important to look at the length and angulation from ring to ring. Leatherwood says there might be a decorative curvature to the shank, but measurements should be evaluated from ring to ring only.

Types of Western Bits and How They Work

O-ring snaffle

What it is: A jointed, two-piece bit with sliding or fixed round rings. The mouthpiece, headstall and reins all attach to a single ring.

Variations: D-ring, eggbutt or full-cheek side rings; twisted, copper or dog bone mouthpieces.

How it works: This bit applies the simplest form of pressure—direct pressure—from the rider’s hands to the corners of the horse’s mouth. When a full-cheek or D-ring snaffle is used, pulling on one rein will cause the ring on the opposite side of the horse’s mouth to press into the horse’s face, applying additional pressure to move his head.

How it doesn’t work: This bit does not apply leverage.
Best for: Younger horses and novice riders. However, it’s not a bad idea to refer back to a snaffle with horses and riders of any level. Leatherwood says if you can take a step back and effectively communicate with your horse in a snaffle, your horse will be able to perform well in a curb bit.

Curb bit

What it is: A curb bit works from indirect pressure or leverage, and it is defined as a bit that contains separate attachment points for the headstall and reins. Leatherwood says it’s a common misconception that if a mouthpiece if broken or hinged, it should be considered a snaffle bit. Bits are actually classified by their bridle attachments.

Variations: Length of shank, straightness of shank, mouthpiece and swivel. Bits that have broken mouthpieces and/or swivel cheeks are slower-acting and provide the horse with what essentially amounts to a preparatory signal. Other types of curb bits include cathedral port, bits with multiple jointed mouthpieces and solid mouthpieces.

How it works: Leverage over the poll of the horse allows you to apply minimum pressure with the greatest response. When you pull back on the reins, pressure is applied not only to the horse’s mouth and chin, but also to the horse’s poll. As the rider pulls back on the reins, the purchase—or top part of the shank—moves forward as far as the curb strap will allow, which puts pressure on both the chin and the poll.

How it doesn’t work: Direct pressure on the horse’s mouth
and lips.

Best for: Advanced horses and riders. An inexperienced rider lacks the hand control to use more severe bits effectively without damaging the horse’s mouth. Inexperienced horses often have not learned the desired response to bit cues, so a bit like this might confuse or overwhelm the horse.

Correctional Bit

What it is: A variation of a curb bit. This bit has long shanks to create leverage action and the port is a high-set, usually rounded, section of metal that sits in the center of the mouthpiece. It is used to place pressure on the roof of the mouth, while the leverage action creates pressure on the rest of the mouth, largely the bars and tongue.

Variations: Port height and width, mouthpiece diameter, shank length and angulation such as forward versus inward toward the horse.

How it works: Indirect pressure. The jointed and curved port allows for relief from pressure on the tongue.

How it doesn’t work: Direct pressure to the horse’s mouth and lips.

Best for: In the right hands, these bits can be used safely as experienced riders and trained horses rely on minimal rein contact and no harsh pulling. Edwards says a correctional bit with a smooth transition is the kindest bit you can put in your horse’s mouth—in the proper hands.

Hackamores and Bosals

What it is: Hackamores are a type of bitless bridle. A bosal is the name of the nosepiece for some kinds of hackamores. It is generally made of a rawhide tube that may or may not contain a metal insert. The bosal surrounds the muzzle and has a large knob on the chin side called the heel butt, where the mecate and bosal reins are attached.

Variations: Mechanical hackamores and sidepulls.

A mechanical hackamore is a nosepiece of leather, rubber-coated chain or rubber with a curb chain and shanks.

A sidepull is a nosepiece with reins attached to rings on both sides of the nose.

How it works: A bosal works with indirect pressure against the horse’s poll, nose and chin. Hand placement is important in steering with a bosal—it needs to be low and wide. When you apply pressure with your left hand, for example, it creates pressure over the right cheekbone of the horse. A mechanical hackamore applies pressure over the nose and chin instead of the mouth. When the reins are pulled, the crown of the bridle is pulled down against the horse’s poll.

How it doesn’t work: Direct pressure on the mouth. The mechanical hackamore provides no lateral signals for steering. All lateral cues come from the rein laid on the horse’s neck.

Best for: Bosals are ideal for advanced riders and young horses. Mechanical hackamores are useful for horses with mouth injuries or a tendency to toss their heads. Sidepulls are often used on young horses before a bit is introduced.

ABIGAIL BOATWRIGHT is a freelance writer and photographer based in Texas.

This article originally appeared in the January 2015 issue of Horse Illustrated magazine. Click here to subscribe!