Pelham bits are very common with both English and western versions of this bit. Like any bit, it has its pros and cons, and there are people who think it’s a great compromise and others who think it is a crutch. But any bit, in the wrong hands, can be ineffective and even abusive. Here’s what a pelham does and when it may be used.
The pelham bit can have a solid or jointed mouthpiece. There is a large ring directly connected to the mouthpiece on to which the 'snaffle reins' attach, and shanks that extend down terminating in rings on which 'curb reins' attach. Because the pelham bit has leverage action, a curb chain or strap loops under the horse's chin to prevent the bit from rotating too far and also provides another pressure point. A small 'lip strap' on the bit shown prevents the horse from trying to nibble at the shanks.
The pelham bit is often used for schooling and general riding, providing the rider is knowledgeable about using a curb bit and riding with double reins. An English Pelham bit somewhat mimics the action of the bridoon (small snaffle bit) and weymouth (curb) bit combination used on a 'double bridle.' A Pelham may be used when a horse cannot hold the two bits comfortably, or for convenience.
Pelhams are seen on some field hunters, in some show hunter classes, on eventers, and in stadium jumping. It is not used in dressage. It is commonly used in polo. There is also a western version of the Pelham bit, and there are driving bits similar to pelhams.
The Pelham provides a somewhat muted effect of the bridoon/Weymouth combination. With the curb rein, the rider can lower the head, and this is useful when schooling and encouraging proper head carriage. Activating the curb rein puts pressure on the bars of the mouth, chin, poll and if there is a port, the roof of the mouth.
With the snaffle rein, the rider can lift the horse's head. As with all English snaffles the pressure will be on the bars of the mouth only. For general riding, the rider would be most likely to ride on the snaffle rein, using only the curb rein when necessary. This requires steady, knowledgeable hands to be effective and not pull on both the curb and snaffle rein together.
Sometimes, if a horse is a hard puller, the curb and snaffle rings will be connected by a leather adapter (also called converters or roundings) so that only one rein is connected to the center of the adapter. This activates both snaffle and curb actions of the pelham. When using only two reins, the rider can't position the horse's head as effectively.
For training that requires a very refined response to the bit aids, such as advanced dressage, the Pelham is not a good choice. The double bridle, with its two separate bits, is more effective for giving clear signals through the reins.