Curb Bit Basics

Curb bits are suited for more mature horse (4 to 5 years old) with the capacity of accepting more pressure from the bit and more pressure on their face.

Curb Bit leverage magnifies the pressure from the rider’s hands to the horse’s face (see Leverage). While a snaffle bit exerts only as much pressure on a horse’s face as the rider is actually applying, the mechanical action of the curb cheeks against the chin strap and poll strap of the bridle enhances the chin pressure that magnifies the bar pressure in the horse’s mouth (see Bars) and engages the poll strap for pressure on the poll.

The basic mechanics of a fixed-cheek curb bit make it a poor turning bit because it has poor lateral abilities. However, it is a great stopper. (Poorly used, it may cause a horse to throw its head up or out of the turn to escape the curb action.)

Because they were used primarily for working horses and cowboys who needed one hand free for roping, shooting, and hat-tipping, most are designed for one-handed riding as opposed to the two-handed style of the snaffle bit.

They may have a solid mouthpiece or the jointed mouthpiece of a snaffle bit. The solid mouth is the type of bit we will concern ourselves with here: The conventional curb bit in which the butt of the mouthpiece is set solidly into the cheeks, and the cheeks do not work independent of each other.

Simple Curb Bit
Simple Curb Bit

The mouthpiece has a port (bump of various size in the middle). The horse’s tongue makes a large pillow in his mouth, filling the mouth from lower jaw to palate when at rest. The curb bit sits gently across this pillow, held off the bars on the sides by the plump pressure of the tongue up against the palate. When the curb is engaged (that is, when the mouthpiece is squeezed down onto the bars by the vice action), the port offers the tongue some place to go under pressure, slipping up into the port space and avoiding pressure in the center of the tongue. A high port gives more tongue room. But with the tongue high up into the port the bit sits lower on the sides and reaches the bars of the mouth more quickly to transmit a stronger signal. That is, a high port bit has less “pillow” supporting it on the sides and offers faster and more pressure directly to the bars.

curb horse bits

As the reins pull back toward the horse’s chest, the shanks rotate back and up until the curb strap stops the rotation. The pressure tightens the curb strap under the chin – effectively putting the horse’s lower jaw in a vise-like grip between the mouthpiece and the curb strap. The grip pulls the bit down onto the bars of the mouth. (The rotation also lifts the port up into the palate if the port is high enough.) When the curb action is engaged, the the nerves of the chin are more sensitive than the bars and tongue. Therefore, care should be taken to use a leveraged curb bit lightly, or the horse’s head will fly up in an effort to avoid the curb strap instead of collecting and keeping his head down where you want it.

The time it takes between the rein cue and the shank moving far enough to engage the curb strap is known as the “signal” time. If the shanks are adjusted at a proper angle (usually about 45 degrees), the horse will have time to realize that the shank is moving and prepare for the action before the bit is actually engaged. If properly trained, he will anticipate the request the moment the rider picks up the reins, and only leg or body aids will be needed to direct his movement. (See Signal)

A bit with a looser curb strap and a longer shank will have a longer “signal” time because there is more distance from reins to curb strap engagement – giving the horse longer to compute the next step. Additionally, when a bit is balanced so that its rein loops hang a little forward of center when not engaged by the reins, it takes just that fraction of a second longer for the reins to take up the slack, which lengthens the signal time. A bit balanced this way is an advantage for quick release of pressure and reliable neutral position. A bit is “balanced” if, when the reins are dropped, the bit immediately swings forward to its “home” or vertical position and releases all pressure. (see Release Training) If properly balanced, when the rider is not “on the reins”, this bit will rest comfortably in a horse’s mouth, allowing him a lot of tongue relief and affording no other pressure

Quick Release is critical for all training. A long signal time is desirable. Short signal time is to be used only by the most experienced riders.

loose-shank low port horse curb bits

There are hybrid bits with loose cheeks and solid mouthpieces. The bit at the left has both loose shanks and a solid mouthpiece – not quite the usual “cowboy” curb bit but a good transition bit. The low, wide port offers more room for the tongue of a horse who is ready to leave his broken-mouth, tongue-trapping bit and start to learn how to wear his solid-mouth bit. The curb strap attaches at the top where the headstall also attaches to the bit.

If the Dee rein loop is used, this bit works similarly to a D-snaffle with some lateral ability and no leverage. If the lower rein loop is used, it engages the chin strap, which leverages the poll AND pressures bars as curb action and leverage is added. The loose-cheek offers somewhat similar lateral pull as a Dee snaffle for the horse in transition.

The term Grazing Bit was developed when cowboys needed a bit that their horse could use for grazing in their bridle. It has swept-back shanks that mitigate the leverage – softening it. However, the fact that the shanks are bent back shortens the signal time. They are already several degrees into the 45 degree angle that adds time to your reins. Reins engage more quickly and should be used by intermediate riders whose aids are well developed.

Curb Bar

While this Quick Stop with Rope Noseband has no mouthpiece, it certainly has leveraged cheeks that apply pressure to the chin bar, which is forced up onto the sensitive, non-muscled area of the jaw bone. The cheeks magnify the pressure to encourage a very fast whoa. Not for a novice rider or trainer, as it can be very severe.

Snaffle Bit to Curb Reverse

When a horse changes from a snaffle bit to a curb bit and is asked to change his direction using neck reining techniques, the bit will be very confusing. A significant amount of training using simultaneous rein cues will be necessary to avoid your horse “reversing” the cues. (When the reins on the neck side of a curb bit are laid against the neck to cue the turn, that rein is shortened – actually feeling to the horse like he should turn into the short rein.) That “reversing” effect must be overcome if you want to move to a one-handed curb bit.

Loose-shanked or loose-cheek snaffles, loose-cheek Argentine or loose-cheek curb bits retain independent lateral movement on each side of the face. They are sometimes used as a bridge to the curb bit, although they have their drawbacks too.

What is the “BEST” curb bit for an intermediate rider on an experienced horse?
A fixed-shank curb bit is more forgiving of uneven reins, as its effect is felt multilaterally (on both sides of the face). A medium port mouth will give tongue relief without acting on the palate. An “S” shaped shank usually balances to release quickly. (see Release Training) The same shanks offer more leverage but less subtlety of signal.

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7 thoughts on “Curb Bit Basics

  1. I love my jacquima headset. Vaquero style bridle. I can utilize by giving side pull dire too. Or direct contact with my reins. Bit not necessary with this style of bridling. My horse was trained in one, plus I can use but, but have no need!

  2. Whoa, whoa, whoa. That is not a spade, and it certainly does incorporate a curb strap. The curb strap goes in the top ring alongside the headstall.

    1. H Alex: Thank you for the correction. This was a written many years ago, and could use some corrections I am sure. I welcome any input you can give us to fine tune this discussion. We are changing the site right now, so this is the perfect time to make the necessary correction that you have pointed out about the curb strap in the text. Any other comments will also be appreciated.

  3. I’m just a nobody. But I think that all bits are harsh. Leverage bits further to help with making your hands even lighter. The thing I think most people don’t get is that your horse needs to be ready for a leverage bits so you don’t inverts injure it. If you don’t have a very well schools horse you’re just causing more pain instead of lighter hands.

    1. HI Corey: I cannot argue with you. Leverage bits (or any bit) can be harsh, and no horse should be using one who has not been educated to its use with a rider who is also both educated and subtle with their hands. A bit should be seen as only a reminder, not a controller.

      It is unfortunate that when a horse gives a rider trouble, the first desperate grab is for a new, harsher bit instead of an in-depth and honest assessment of the rider’s abilities or the horse’s training.

      I am a strong proponent of Side-Pulls and Bitless Bridles. I start and frequently leave my horses in a side-pull bridle. It takes extra precise ground training before saddle training, but it pays off with a horse who understands all of the cues without the use of a harsh mouth correction.

      (This comment was moved from Copper Bits to this page as it seemed more appropriate for this discussion)

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