Herewith, the short version of the "bit talk".

What bits do:

they serve to communicate something to the horse (duh!). What they communicate can be strongly effected by their shape, weight, and general style, as well as what sort of hands are on the other end of the reins from them. A long shanked curb in heavy hands will be more severe (able to cause pain) than a French link snaffle in the same hands because the curb is designed to exert leverage pressure on the jaw, which magnifies the pull of the hands -- the snaffle is not designed to exert leverage and only gives a one to one pull (one pound of pull = one pound of pressure on the mouth).

What designs do what:

• true snaffles, with no shanks, most often work to lower the head and neck of the horse *if* he is accepting of them and not being poked in the roof of the mouth by the bit, in which case they often result in the horse raising the head and neck and nosing out. (star gazing)
  
  
• Curbs generally raise the head at the poll, but bring the nose in toward vertical, again *if* the horse is accepting of the bit and works in it as a trained horse. Otherwise, they will again cause the horse to nose out and raise the entire head, star gazing again.
• Gags work to raise the head and neck and to bring the nose out.

Mouthpieces will effect the way a bit works:

• In snaffles:
  • A broken mouthpiece (single break) will enable the bit to work independently on each side of the mouth, which makes the design useful for teaching lateral bending. Again *if* it is accepted by the horse -- if he has a low palate, thick tongue or other mouth conformation that makes a single joint uncomfortable, it will not work to teach anything but resistance (again, with the nose out and head up)
  • A double broken mouthpiece (french link) will avoid the roof poking problem and allow some horses to work more comfortably while learning lateral flexibility. However, this mouthpiece may be too busy for some horses and again produce the nose up, high head, resistance in them.
  • A roller mouthpiece that limits the bend of the bit may work better for teaching lateral flexibility for some horses, because it allows some give on each side of the bit, without wiggling excessively or poking the roof of the mouth. For other horses, this design is also uncomfortable, and again results in the nose out star gazing response.
  • A mullen design which forms a shallow arch over the tongue when the bit is carried correctly in the mouth does not allow as precise a signal for lateral flexibility training, but will work for horses that do not tolerate other types of snaffle bits. The mullen works more on the bars and lips than on the tongue, but does work on the tongue too. Pretty mild signal for any mouth, and it does encourage the horse to reach down and forward, even if he does not do that in any other snaffle bit. If you have a horse that fights in a regular snaffle, noses out and star gazes, the mullen may be more comfortable and may help him accept cues for head lowering and bending that he was too distracted to respond to in another more traditional snaffle.
  • the "comfort snaffle" design, which is a sort of bent rather than arched mullen in some manufacturers' bits, with or without a roller over a join, works more strongly on the bars than the regular mullen design. This bit may be more acceptable to some horses than a typical ring snaffle, and may bring their heads down somewhat. However, because of the bend of the branches of the mouthpiece over the bars, this design places more pressure on the bars and sides of the lower jaw than the more common mullen does, and for some horses it is too much pressure -- resulting in them going "behind the bit" or refusing to reach down and forward into the contact of the snaffle. If your goal is setting the horse's head, however, this design works to cause them to flex at the poll more easily than a regular arch mullen.
  
  
  
• In Curbs:
  • A arch mouth curb may allow more room for the tongue than other "port" designs, and a true mullen may also allow more room for the tongue, as it arches over it in the mouth.
  • a low port curb allows some tongue room in the center of the mouthpiece, not much at the sides, and rests more on the bars than the tongue.
  • A higher port curb can rotate in the horse's mouth (depending on how the curb strap is adjusted) and poke the roof of the mouth -- this may result in star gazing, or it may encourage the horse to lower his forehead to vertical to relieve the pressure ... this depends a lot on the horse and how he has been taught to accept the bit. Most high port bits do not allow all that much room for the tongue, although the myth is that they give more tongue relief than a lower port.
  • a cathedral or high narrow port mouthpiece will again hit the roof of the mouth if it rotates too far, works as a tongue depressor (and are sometimes recommended for horses that get their tongues over the bit) but also works as a head setter (brings forehead to vertical) because of the pressure of the port on the tongue.
  • a broken mouth curb, with a single break, works as a sort of nut cracker on the lower jaw, although it does allow some independent use of one side or the other of the mouthpiece for lateral flexibility work. However, the nutcracker effect usually trumps this use, by peaking in the middle and causing the horse to raise his head and often star gaze. Often horses work in these bits if the reins are not used at all (kept totally slack with a loop in them) but at the first hint of contact, the head goes up and often, they become unquiet in the mouth, chewing or head tossing as a sign of discomfort.
  • a broken mouth piece with a double joint or rollers over the joint does not hit the roof of the mouth, but it may clamp around the sides of the jaw and bars, and can again cause a fair amount of discomfort if used with contact. This bit will also often cause a horse to raise his head, but usually without nosing out (not always). Shanks we have talked about. Purchase we have also mentioned. Shank length works more on the jaw, purchase length more on the poll. A short shanked bit with a long purchase will work on the poll, and may work to lower the horse's head more than a longer shanked bit with a short purchase. Both will provide pressure on the horse's head as well as in his mouth, but in different locations.

So, in short .. a shanked bit with a single broken mouthpiece will most often raise a horse's head and can cause him to nose out. A shanked bit with a low port will most often cause the horse to raise his head, flex at the poll and move his forehead toward vertical. A non shanked snaffle, with a single join may or may not encourage a horse to lower his head and reach forward and down. A non shanked mullen snaffle will strongly encourage a horse to reach down and forward.

In a combo bit like the pelham, you have to realize that the mouthpiece is going to be working as both an attachment of the snaffle (no leverage) and as an attachment of the curb (leverage). The mouthpiece that may be useful for lowering the head as the snaffle (jointed) will operate differently when leverage comes into the picture, working to raise the head and make the horse nose out as the curb.

It is possible through the use of the hands to employ a bit for a purpose other than that most likely from its design. You can raise a horse's head and get him to flex at the poll in a jointed snaffle, if you ask correctly.

You can lower a horse's head and encourage him to reach forward in a curb, if you are delicate about it. You can also use a screwdriver as a wood chisel, but it is not the best tool for the job!

I haven't even talked about curb straps vs chains, balance, weight, workmanship, how to tell a well made bit from a piece of junk, etc. In brief, you want to use a bit that is balanced, not bent or crooked, of moderate weight, not so light the horse doesn't notice it in his mouth ( weight in a curb is one of the things that encourages the "curb" head position) has no rough edges, in which the purchase is slightly bent away from the face of the horse (actually, in a full cheek snaffle, this is also important to prevent the upper "branches" of the bit from digging into the horse's face), there are no worn or sharp places where the bit can pinch the lips of the horse, there are no gaps in any swivel joints that can catch a lip or a tongue, and is made of metal that has no pits or flaws in it.

Whew .. there is so much more on this topic, but I think I will rest my fingers now.

Lee Z©