Pelham bit
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A pelham is a type of curb bit used when riding a horse. It consists of a mouthpiece, a shank, a curb chain, 2 rein rings per side on the shank, and one cheekpiece ring on the top of the shank. The top rein ring is located next to the mouthpiece, as in a snaffle, and the rein that attaches to it is thus called the snaffle rein. The lower ring, at the bottom of the shank, is called the curb rein due to its curb action.
Due to the severity of the curb in relation to a snaffle, it should not be used by novice riders. Double reins are also more complicated for a novice to handle. The pelham should be ridden mainly off the snaffle rein, with the curb rein only coming into effect when needed. Oftentimes, a bit converter is used so a pelham can be used with only one rein. This is especially helpful in the cross-country phase of eventing, so that when the reins are slipped only one must be shortened. If used with two reins, the snaffle rein should be wider to help distinguish it from the curb.
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[edit] The Action of the Pelham
A pelham works on several parts of a horses mouth.
- The bars: applied by the mouthpiece, and directly related to the length of the shank of the bit. The curb chain and a high port can also increase the pressure placed on the bars of the mouth.
- The tongue: applied by the mouthpiece, with the pressure related to the thickness and type of mouthpiece.
- The roof of the mouth: only applicable if the mouthpiece of the pelham has a high port.
- The poll: severity is directly related to the length of the upper shank in relation to the lower shank. All pelhams apply at least a little pressure on the poll.
- The chin groove: pressure applied by the curb chain when the curb rein is used.
- Side of the jaws: a pelham may add some pressure to the sides of the jaw due to its length.
[edit] The Shank
A pelham is a leverage bit, meaning that is multiplies the pressure applied by the rider. Unlike a snaffle bit, the curb rein can amplify the rein pressure several times over, depending on the length of the pelham's shank.
The relation of the upper shank--the shank length from the mouthpiece to the cheekpiece rings-- and the lower shank--the shank length from the mouthpiece to the curb ring, is important in the severity of the bit. A long lower shank in relation to the upper shank increases the leverage, and thus the pressure, on the curb groove and the bars of the mouth. A 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.
Shank sizes vary from the Tom Thumb (2 inches long) to several inches, although most are less than 4 inches.
[edit] The Mouthpiece
The pelham's mouthpiece controls the pressure on the tongue, roof of the mouth, and bars. A mullen mouth places even pressure on the bars and tongue. A port places more pressure on the bars, and provide room for the tongue. A high port may act on the roof of the mouth as it touches, and will act as a fulcrum, amplifying the pressure on the bars of the mouth.
Jointed mouthpieces increase the pressure on the bars as it breaks.
[edit] The Curb Chain
The curb chain applies pressure to the curb groove under a horse's chin. It amplifies the pressure on the bars of the horse's mouth, because when it tightens it acts as a fulcrum.
[edit] Fitting the Pelham
Pelhams are generally placed lower down in a horse's mouth than snaffle bits, near or in the corners of the mouth. The lower the bit is placed, the more severe it is as the bars of the mouth get thinner and so pressure is more concentrated.
The curb chain should be adjusted correctly, lying flat against the chin groove and only coming into action against the jaw when the curb ring is rotated 45 degrees.
