The Bridle Wars Part 2: Understanding Leverage

There are a million bits out there, so many that the latest Dover catalog devotes a full 7 pages to them, and Dover by no means carries every bit in existence. However, there is a trick to understanding the function of every one of those bits. Most bits are a combination of one of a handful of ring designs and one of a handful of mouthpiece designs. Understand those two handfuls and you can make a pretty good guess at what any bit will do. In this post I discuss ring design and its impact on leverage.

When we refer to leverage with regards to bit design we usually are referring to the application of pressure to the bars of the horse's mouth, the horse's poll, and if a curb chain is used, to the horse's chin. The more pressure in more places, the more force a rider can exert to stop, collect, or otherwise adjust a horse's forward movement. How much pressure is exerted is a function of how far apart the minimum distance is between the mouthpiece (Point C) and the cheek piece (Point A) and how far apart the minimum distance is between the mouthpiece (Point C) and the rein (Point B).

In the diagram above with a loose ring snaffle there are no fixed points (all three points can rotate freely around the ring) therefore the minimum distance in theory could be zero. As a result a loose ring gives the least amount of leverage of all bit designs. In an eggbutt, dee ring, or full cheek design the mouthpiece is fixed while the cheek piece and rein can move. This offers very slightly more leverage, but not enough that most riders would notice a difference in the horse's response. So why do we bother with eggbutts, dee rings or full cheeks?

The primary advantage of an eggbutt is purely that it cannot pinch the corners of the horse's mouth, which can be a problem with a loose ring, particularly if the bit is either the incorrect width or adjusted too high or too low in the horse's mouth. Full cheek snaffles were created to apply pressure on the outside cheek when the inside rein recieves pressure. This can be an advantage for a green or stubborn horse. Dee ring snaffles also apply pressure to the outside cheek, but because the ends are connected they cannot get hung up on anything. This makes them safer when riding with others or riding at speed.

But what if we want more pressure than a loose ring, eggbutt, dee ring, or full cheek will provide? To increase the pressure we must fix additional points. An unusual bevel ring fixes the cheek piece and the rein and allows the mouthpiece some limited movement. As the rein is tightened in the rider's hand, backward pressure is applied to the horse's mouth, and if sufficient pressure is applied to the rein to rotate the ring downward pressure will then be applied to the horse's poll. This makes the bevel an intermediary bit between the previous four types discussed and the increased leverage bits to follow. Still need more pressure?

The baucher fixes the mouthpiece and the cheek piece and leaves the rein with a small degree of movement. The greater fixed distance between the mouthpiece and cheek piece creates simultaneous backward pressure upon the horse's mouth, and downward and slightly forward pressure on the horse's poll. This combination of leverage is useful in stopping a horse who tends to pull, or in creating collection.

The elevator bit, sometimes seen with only one lower ring and called a show jumping bit is similar to the bevel in that the cheek piece and rein are both fixed and the mouthpiece has some limited motion. It's action is similar as well. Pressure is primarily upon the horse's mouth if applied lightly, if increased pressure is applied, the pressure is also applied to the horse's poll. However especially if the lowest ring is used the elevator will apply many times the pressure of the bevel because the distance between the cheek piece and the mouthpiece and the mouthpiece and the rein are much greater. A longer lever = more pressure. A variation on the elevator bit is the wonder bit.

What if we want even more leverage? The introduction of a curb chain running under the horse's chin applies pressure in a third place. In a kimberwicke the pressure is the least, similar in action to that of a baucher with the addition of upward and forward pressure on the chin when the rein is tightened. A weymouth has much greater pressure, similar in action to an elevator with the addition of upward and forward pressure on the curb chain.

It should be noted here that weymouths because of their severe pressure should never be used as a single bit. They are for use in double bridles along side a bridoon (a thin mouthed loose ring). As part of a double bridle the primary action is that of the bridoon with the weymouth being used to enhance the riders ability to collect the horse.

A pelham is something of a two in one bit intended to mimic the action of a double bridle when rigged with two sets of reins, one attached to the large ring, one to the lower ring. If used with one rein attached to the large ring its action is similar to a kimberwicke, if that single rein was attached to the lower ring (not recommended) its action would be similar to the weymouth. It can also be used as a kind of false double bridle by connecting the reins to converter straps that buckle onto the large and lower rings, causing the single set of reins to act upon both sets of reins. (See image at right.) The action of such an arrangement would be similar to that of a kimberwick, although with greater leverage.