Selecting the Proper Bit

Horse’s possess seven control (pressure) points on and around the head where pressure of some type may be applied to direct and/or control a horse. The points are: the mouth, the lips, the tongue, the bars, and the roof of the mouth, the nose, chin groove and the poll.  The horse learns that pressure in a certain area means to slow down, stop, turn or change his head position. The lips control the height and width of the bit. Too narrow of a bit will pinch the soft skin at the corners of the lips and too wide a bit will produce the same result as a lot more pressure will have to be put on the reins to get some response from the corners, increasing the pressure on the soft corners of the lips. Applying pressure to one or more of these pressure points will cause the horse to react in certain ways.

The Snaffle Bit

The snaffle bit is a direct pressure bit. Direct pressure means if you use two ounces of pressure on the reins, the horse feels two ounces of pressure on his/her mouth or nose from the bit.Direct pressure bit. Acts on the tongue, the bars in a straight snaffle and the sides of the bars in the case of a jointed snaffle, and the lips and corners of the mouth.  The distance between the upper and lower jawbones when the mouth is closed determines the choice of bit thickness.  The bit, no matter what thickness, should fit comfortably over the tongue and on the bars without cutting into either the tongue or the bars.
Parts of a snaffle bit

  • Stainless Steel - most common metal
  • Other Metals (Copper, Sweet Iron, German Silver) encourage salivation and chewing of bit
  • Synthetics (Rubber, “Happy Mouth”) - some horses accept these better than metal
  • The diameter of the mouthpiece typically varies from 5/16 inch to 3/4 inch, although there are smaller & larger sizes

Number of pieces:

  • Mullen Mouth - No joints, straight pressure on the bars.
  • Single Joint - Single joints create a nutcracker effect that acts on the bars of the mouth, over the tongue and on the lips
  • French Link - mildest of the snaffle bits, the three pieces relieves pressure on bars


  • O-Ring or Loose Ring - the mildest
  • D-Ring & Eggbutt - adds slightly to severity
  • Full Cheek - adds cheek pressure & prevents bit from pulling through mouth


  • Rollers give the bit some “play” and also prevents the horse from “grabbing” the bit. Rollers can be made of stainless steel or copper.

The Curb Bit

The curb bit is considered a leverage bit. The bit works in conjunction with a curb chain, consisting of a straight mouthpiece attached at either end to long metal cheeks or shanks. All curb bits act on the nose, bars, lips, chin groove and tongue. Curbs with long shanks also act on the poll, and those with high ports act on the roof of the mouth. The action on the chin groove is via the curb chain, which acts as a fulcrum and without which the curb bit would only act as a snaffle.  A curb bit works by leverage on the lower jaw, applying pressure on the chin groove by means of the chain. The longer the lower section of the metal mouthpiece, the greater the pressure applied to the lower jaw.

Curb Strap

  • Should permit the bit to pull back 45 degrees. A general suggestion is that two fingers will fit between the curb chain and the animal’s chin. Also make sure that there are no knotted or twisted materials underneath the animal’s jaw.

Port HeightParts of a curb bit

  • Upward curve centered on an unjointed mouthpiece; included to provide tongue space or discourage the tongue from getting over the bit; ranges from a slight undulation in the outline to an extension measuring an inch or above. Low port curb - Provides small space for tongue to squeeze into and reaches the bars later.  Applies tongue pressure first, and then pressure to the bars. High port curb - Slightly more severe.  Bit touches down on bars earlier and tongue is pressed up into large, but narrowing port as it rotates.  Lays down forward into the tongue and bars when rotated with a pull on the reins


  • The part of the bit above the mouthpiece. With a short purchase, the bit will act quicker in the horse’s mouth when the rider pulls on the reins. The bit is slower to react with a long purchase

Shank Length

  • The shank length increase the leverage action of the bit. The shorter the shank, the less severe the bit.

Shank Bend

  • A suitable bit’s shanks will bend back towards the horse’s body, decreasing the severity of the leverage.

There are hundreds of different bits in the market place. Bit selection will depend on the types of classes the horse is shown in as well as the age of the horse. Always choose the mildest bit the horse will work with to accomplish the job required.