It is essential to both the rider and the horse that the tack fits properly. If it doesn’t fit comfortably or correctly, it will be painful for the horse, which may cause it to resist the aids given by the rider. A saddle should be specifically fitted to a horse, for some hard-to-fit horses you may need to have one made. Loose-fitting tack may fail to pass a given signal to the horse, or it may come off, causing a serious accident. If you have any doubts about equipment you are using, consult an expert from your local tack shop.
The saddle should lie straight on the horse’s back, resting on the ribs, not on the spine. The sides of the horse’s chest are nearly parallel at this point, and this helps to keep the saddle in place. The saddle must be fitted without a pad. It should not be so long that it puts weight on the horse’s loins. When the horse’s head is down, you should be able to see right through the gullet; the gullet is designed to keep weight the horse’s spine. Check that you can see through the gullet when the girth is fastened and when a rider is sitting on the horse. A chalk mark test can be done to ensure a proper fit. To conduct one, dust the saddle’s underside with chalk and place it on the horse. When you remove it, a chalk mark will show if the saddle touches the horse where it shouldn’t.
A saddle must be the same width as the horse’s shoulders. If it is too narrow, it will pinch the spine and restrict movement. If it is too wide, it will be low on the withers. The pommel lies over the withers. It must be high enough to allow the horse to lift its head up without causing the withers to press against the pommel. A well-fitting saddle sits securely even before the girth is fastened. If it moves around too much while you are riding, it will rub the horse’s back.
A cavesson noseband is fastened loosely, with room for two fingers between it and the nose. A drop noseband should be tighter, because it is meant to hold the bit in place and keep the horse from opening its mouth too wide. The noseband should lie about midway between the mouth and the projecting cheekbones. You should be able to fit two fingers below the cheekbone. The sidepieces of the noseband must not touch the horse’s eyes. The throatlatch must be long enough to allow four fingers between it and the horse when it is fastened. If it is tighter, it can interfere with the horse’s breathing. You should be able to fit two fingers under the browband. It must not pull the crownpiece and cheekpieces, but should allow them to lie in a straight line.
Look carefully at the bridle on the horse’s head from the front. Make sure that it is straight and positioned symmetrically on both sides. The browband should lie under the forelock; the noseband should sit on the bridge of the nose. A poorly fitting bit will be uncomfortable for the horse and can injure the mouth. All bits should lie in the corners of the mouth without wrinkling the lips too much; the horse should look as if it is smiling. If the bit is too high it will rub the corners of the mouth; if it is too low, it may hit the teeth. The mouthpiece should stick out ¼" on each side when you hold the joint straight in the mouth. If it is too wide, it will move from side to side and rub; if it is too narrow, it will pinch the lips.