When looking for the proper bit for your horse the choices can become very overwhelming. The following cursory information of the different bits can help make a seemingly complex decision much less so.
The snaffle bit consists of either a straight or jointed mouthpiece connected to a variety of ring styles – loose, eggbutt, full cheek as examples. The reins connect to these rings and when used apply direct pressure to the bars, tongue and the corners of the mouth. This bit can exert pressure on both or one side of the mouth, which is why it is used to teach and confirm lateral movement and flexibility.
Snaffles are commonly considered the mildest of bits but this is not true in all cases. Single jointed snaffles will push into the palate of some horses causing discomfort that may lead to tossing or shaking of the head. Over the last few decades multiple jointed and anatomically curved snaffles bits have flooded the market. These bits sit in the mouth with curves that better conform to the equine mouth and therefore do not poke into the palate. This helps to make the invasion of a piece of metal in one’s mouth much less of an issue. My personal preference and experience leans toward the use of such bits.
Curb bits which consist of Weymouths, Pelhams and Kimberwickes along with a few other “specialty bits” all have some sort of shank to which the reins are connected plus a strap or chain that goes under the chin. All work on leverage. This leverage action applies pressure to the bars and tongue, just as the snaffle, but also exerts pressure on the chin groove and poll. None can isolate just one side of the jaw and because of this limitation can only influence the haunches and topline of the horse. All curbs are considered more severe but Weymouths (typically used in conjunction with a snaffle in a double bridle) can, in fact, influence a horse with an exquisitely light touch when placed in the hands of a tactful rider.
Use of a double bridle has been well accepted in the dressage and classical world for a very long time. The double bridle consists of a bradoon which is nothing more than a snaffle designed slightly thinner to allow room in the mouth for the addition of a curb bit. Although it may sound distasteful to put two bits into the mouth of your horse most horses that have already accepted having a metal bar placed into their mouth actually like the feel of two bits. I have seen horses that fuss with a snaffle start sucking and mouthing the two bits much like a child sucks on a pacifier creating a great deal of relaxation.
The advantages of the double bridle are many. The snaffle allows you to better assist all lateral flexion and bending and once the horse is confirmed in all exercises that address such the curb then allows you to begin working on the strength and flexion of the hindquarters and subsequently the topline. It is necessary to separate the action of both bits in order to achieve success with each phase of schooling and to have each available for appropriate reminders.
Pelhams and Kimberwickes are hybrids and combine the effects of both the snaffle and curb. I do not like any of these bits since you cannot separate the effects of either bit action and this can and often does lead to confusion and distortion as to the purpose of each. I see these most used when a horse has been taught or allowed to run into the bit without addressing the root cause of why this is happening – which usually has nothing whatsoever to do with the horse and everything to do with an uneducated rider trying to school from the mouth alone rather than utilizing the body behind the mouth. I have seen these (and all bits) used so harshly that the bars of the mouth are bruised and calloused making every bit ineffective. At this point the horse and rider need re-schooling by a professional that truly understands proper use of all the aids.
There is an assortment of “specialty” bits such as Tennessee Walker bits, Gaited Horse bits, Tom Thumb bits, Gag bits and Anti-rearing bits. These should all be avoided as they are designed to create head-sets, artificial action or to correct problems that really cannot be corrected in the mouth of the horse.
Bit-less bridles have become quite popular and I believe them to be a good addition to the list of control devices for our horses. Since the mouth, reins and hands of the rider should be the last and least used of our aids when properly schooling our mounts the bit-less approach should be no less effective than the bit. I will, however, caution you against long-shanked hackamores as these put too much pressure on the most sensitive part of the nose. The bit-less bridles used in the “Natural” school of thought are kind and effective.