Double bridle
Double bridles are most commonly associated with dressage and certain horse show classes where formal tack, attire and turnout are standard.
Double bridles are rarely used by show jumping riders and eventers in the stadium and cross-country phases.
The double bridle is commonly seen in old paintings of hunt scenes, used by the well-trained gentry as they rode cross-country.
The rider would keep a modest contact with the curb bit to regulate collection and only engage the bradoon bit to raise the head or reinforce leg and seat aids for impulsion and direction if those aids failed to achieve their effect.
A bradoon that is too wide may get caught on top of the port of the curb bit and push the bridoon's joint upward into the upper palate, while one that is too narrow will pinch the horse's skin against his molars.
[4] The upper shank should bend slightly outward, to prevent it from pinching when the reins are pulled.
It is common to place the bradoon a bit higher in the mouth than a snaffle used alone, because it is less likely to get caught on the curb.
[1] The bradoon bit works like any other snaffle, placing pressure on the lips, tongue, and to some extent the bars of the mouth.
In the classical dressage tradition, the bradoon is used to regulate horizontal flexion (bending the horse left and right) and impulsion (faster and slower).
However, because the curb rein is several inches below the bradoon, raising the hands pull upward on the bit and engages the shank.
It is a refined piece of equipment that can greatly enhance the riding in good hands, or destroy the animal's training and mouth.
Additionally, they should be able to keep their horse moving uphill with elevated shoulders, or else activating the curb will cause him to hollow, fall onto the forehand, and flex incorrectly at the 3rd vertebra rather than the poll.
[1] The rider must also take care to determine if a double bridle is proper for the individual horse's training and temperament.
Horses that tend to be lazy or behind their rider's leg will also become more so if ridden in double bridle before they are consistently forward.
[1] Additionally, it can cause unpure gaits, including a "pacey" walk, a stiff trot, and a 4-beat canter.
Running curb reins through the martingale creates excessive amounts of leverage and can cause pain to the horse if misused.
While fox hunters once were known to ride with a running martingale attached to the curb rein, today this practice is relatively non-existent, partly because the double bridle is only common in equestrian disciplines that usually do not use a running martingale.
However, if a running martingale is used on the curb, however ill-advised, it is extremely important to use rein stops, as the martingale ring is sometimes larger than the ring on the curb bit shank, and can get caught on the bit with potentially disastrous consequences.
[2] When first learning to use the double bridle, it can be helpful to gain experience holding and manipulating two reins without actually using the more severe curb.
In every case, a great deal of precise control is needed to selectively engage the bradoon or curb independently.
It demonstrates the horse's throughness, self-carriage, and obedience due to the fact that the rider has little control with the reins except to create flexion.
[4] When used, it can increase the difficulty of the movement, thereby helping the rider attain a higher score if executed well.
Additionally, pressure from the bradoon rein pushing on the underside of the little finger can encourage riders to raise their hands, because it will feel as if there is not longer a perfectly straight line from elbow to bit.
This hold is usually used if the horse is especially hard-mouthed, easily distractible, or needs a bit more curb action because he tries to raise his head.
[4] It should only be applied by riders with exceptionally soft hands who have a good foundation in using the double bridle.
Therefore, either rein can be used without the influence of the other, simply by rotating the lower or upper part of the hand back.
However, when used incorrectly, which can be extremely easy to do even by excellent riders, it causes the horse to flex at the third vertebra instead of the poll, a major fault.
This hold has several important consequences: it decreases the action of the curb, it prevents the rider from riding with their hands too wide or performing an overzealous opening rein with their left hand, and it shows when the horse is not properly straight, because the rider can no longer make the rein pressure on one side of the mouth any stronger than the other, since reins from both sides are held in the left hand.
This method is rarely practiced today, although still seen used by the Spanish Riding School, the Escola Portuguesa de Arte Equestre, and the mounted troops of the household cavalry in London, England.
For practical working purposes, the modern cowboy of the vaquero or "buckaroo" tradition usually keeps a light bosal on the finished horse as a type of noseband.
