Snaffle: A bit that has a rein that connects directly to the end of the mouthpiece (whether by D-Ring, O-Ring, Egg-butt, or whatever).
Shanked: A bit that has shanks or other form of extension above and/or below the mouth piece.
Curb: A shanked bit with a curb strap (note that not all shanked bits are curb bits--if a shanked bit does not have a curb strap, it is not a curb bit--e.g. another form of shanked bits is an elevator bit).
Gag: Though nobody has mentioned these, they do exist; however, they are a bit difficult to describe (and a bit that I consider to be useless, so I won`t go into detail). Suffice it to say, they exist and cannot be properly described as either a snaffle or a shanked bit.
Jointed: A bit that has a jointed mouth piece (this may be any number of joints, but generally there is one or two).
Bar: A bit that has a straight bar for a mouth piece.
Port: A bit with a port in the mouth piece.
Other forms of equine head gear
Halter: AKA "head collar" which is generally used for leading a horse; although, some people do use them for under saddle work as well.
Hackamore: A headstall with a noseband that is connected to shanks, with a curb strap of some sort.
Bosal: Generally, a rawhide loop that goes over the horse`s nose and comes together in a point under the horse`s chin with the reins attached to the point under the chin. There is a version of the bosal that is used by Paso Fino people (and maybe others) which has a headstall with a noseband (of some chosen material, usually leather or rawhide, but you can get metal ones or ones with "spikes" on the inside) and a "strap" under the chin with two rings on it to which you can attach reins.
Vosal: Some mechanical combination of a hackamore and a bosal.
Side pull: A bridle with no hackamore or bit.
Some popular bits
Tom Thumb: Despite the fact that many western people call it, a Tom Thumb bit is not a snaffle. It is a jointed curb--if you put a curb strap on it. If you don`t put a curb strap on it, it is neither a snaffle nor a curb.
Kimberwicke: A mild curb (if used with a curb strap) which usually has two separate placements for the reins on a "D" ring that allow differing amounts of leverage. If you use it without a curb strap then it is a mild elevator bit. It can come in either jointed or unjointed types, and it may or may not have a port.
Pelham: A bit (generally with a jointed mouth piece, but not always) that has two separate attachments for the reins, one as a snaffle rein and one on the shanks. This bit is generally used with a curb strap. There are many classical purists who believe that this is a bastard bit with no place in anybody`s tack room as it is impossible to apply the reins independently if you want to use both the curb and the snaffle at the same time (like you could do with a double bridle). However, polo players find it very useful--so what do classicists know anyway? :)
That said, I will now try to contribute to the confusion that has been going back and forth about bits, vosals, curbs, etc. :)
Let me preface this with a statement that I always make when answering questions about bits (or whatever head gear you choose to put on your horse while you ride it): "Bits are for communicating with horses, they are not for controlling them."
So, if you ask the question, "If I use _________(fill in the blank) on my horse`s head, will I be able to control it?" You are already at a disadvantage. . .as you are asking the wrong question. Instead, the question you should ask yourself is, "Will ________ (fill in the blank) enable me to adequately communicate my wishes to my horse in all the situations in which I find myself?" (Which can be many, when you are out on the trail.)
The answer to this question will always be: "It depends on the disposition of your horse and what it has been trained to respond to, and the hands and seat of the rider that is using it." Therefore, it is impossible to ask a question about bitting (or more accurately, riding headgear) without it turning into a question about training, of both horse and rider.
This is not unlike, "If I go to outer Mongolia, will I be able to communicate with the locals in English?" The answer is: "It depends on whether the local you are talking to has learned English." There is also some validity to the assertion that communicating does not become any more effective by yelling, if the person in question does not understand the language in the first place, e.g. the Outer Mongolian will not understand you any better if you yell English at him than if you speak it to him, if he has never learned English. You also may not be able to communicate with the outer Mongolian that HAS learned English, if you, personally, don`t speak English clearly. In both the instances if you try yelling to enhance your communication, all you will achieve is to irritate the Mongolian. :)
One handed versus two handed bits
The snaffle bit is usually a jointed bit, and it is a two handed bit. Designed for the independent application of each rein (only in extreme emergencies should both snaffle reins be applied evenly--since to do so is rather like putting your horse`s jaw in a nut cracker). Therefore, snaffle bits should not be used by riders who need to "hold onto" the reins (i.e. they do not have enough balance in their seat to be able to ride without holding on with their hands--such riders should not be given reins at all and should spend some time riding with no hands while the horse is longed).
Shanked bits are designed to be used in one hand. With even application on both shanks to apply either the curb or the elevator. Directional reining is done indirectly (AKA neck reining). To apply a curb rein directly does much more than just put pressure on the bar of the side of the mouth that you are applying the rein. Depending on the type of mouth piece and the type of the shanks it will have additional uneven action on the poll, chin, and opposite side of the horse`s mouth.
Why I like the snaffle bit
I start all my horses (and horses that other people ask me to start -- unless they specifically ask otherwise) in a snaffle bit. With ground driving if the horse is 4 or under and with longeing in a surcingle and side reins for horses that are over 4. I like the egg-butt snaffle because it generally doesn`t pinch the lips of the horse like a D-ring or O-ring can. But I also use a Baucher bit. I do not use full cheek because I am of the opinion that one should never be pulling on the reins hard enough to pull the bit through the horse`s mouth (which is what a full cheek is designed to prevent). And I do not use a half cheek as it is designed for use on harness horses.
I choose a jointed snaffle bit because it is the simplest way to communicate with a horse through reins. It is designed for using a direct rein (unlike the curb bit which is designed for using an indirect rein) and the horse can clearly feel just the slightest pressure of either rein only on the side that the rein is applied (which is not true for bar bits, and is not true for the assorted "bitless" things that go over a horses nose--except, of course, for a side pull--about which I cannot comment for I know nothing). And so, have found, that snaffle bits cause the least amount of confusion to an uneducated horse.
Shanked bits have a whole host of actions associated with applying the reins which can be very confusing to a green horse so I wouldn`t dream of starting a horse in a curb (additionally, because of the complexity of the signal associated with applying a curb, I would also not recommend them for riders that have not mastered an independent seat even on well trained horses, since they may accidentally apply a rein giving a confusing signal to the horse; the result being that the horse will either learn to ignore the signal or avoid it--both things being something that you don`t want your horse to learn).
The tom thumb, because it is a jointed curb, is an extremely complicated bit, and I would most definitely NOT recommend it for any horse and/or rider that is having "bitting" problems (i.e. there is a lack of communication between horse and rider through the reins). It is a bit that requires great subtlety and sensitivity in use, and if subtlety and sensitivity are not used, horses will go through all kinds of contortions in order to avoid its action (this usually includes incessant head tossing).
The pelham also is an extremely complicated bit (not only because it is usually a jointed curb, but also because of the action of two separate sets of reins on the same mouth piece), and I would not recommend it for any horse that is having "bitting" problems either (although their have been instances when I have chosen to use this bit). Frequently, people will ask me (since they are having trouble getting their horse`s attention, and he is "leaning" on the snaffle bit and they have no control over their horse) if I would recommend a pelham. My response is generally, "Pelhams can be useful if used with finesse, but generally speaking. . .you already have a hand full of horse, do you really want to also have your hands full of reins?"
It is, of course, possible to teach a horse to respond (or not respond) to all kinds of complicated actions of the bit, but you risk confusing the hell out of the horse while it is learning, especially if you, yourself, don`t have good control over your hands.
I generally avoid using halters or bosals (anything that goes over the nose) on green horses as it is their inclination to lean on it rather than yield to it and to look to the rider`s hands for support. I have one horse that I am currently working with who actually seeks to lean on the noseband of his bosal (19 y.o. Paso Fino), to the extent that even if you don`t take up the reins he will push his nose into the noseband, if you give, he pushes more and he does this by poking his nose forward. There is absolutely no way to communicate with this horse through this bosal with the way that he chooses to "carry" it. A snaffle bit, on the other hand, is uncomfortable to lean on; and horses, when given a few leg cues, quickly learn that the most comfortable thing to do (as long as the rider does not also hang on the bit) is to yield to it.
The mechanical hackamore (on the other hand) is a type of equine headgear that I consider appropriate for only the most advanced of horses (and for me, if my horse is that advanced, I am going to put him in a double bridle--so I consider it to be a useless piece of equipment). Because it is a shanked device, it is designed for use in one hand and for directional control, the hackamore is designed for using an indirect rein and should not put any pressure on the shanks of the device at all. The application of the reins has the effect of putting the horse`s head in a vice: it puts pressure over the nose, it puts pressure under the chin, and it puts pressure over the poll; and in the hands of a heavy handed rider (or an only partially trained horse that has not learned to respond to the very light application of the rein) it is an instrument of torture. And make no mistake, a horse must be taught that putting its head in a vice means stop.
If you are having trouble "controlling" your horse in a regular riding situation (if you are an endurance rider, a regular riding situation would be going down the trail with other horses that may or may not be going the same speed as you), the solution is not to increase the "severity" of your bit. You already have a horse that is ignoring the cues your are giving it through the reins--to increase the severity of the bit is to INVITE the horse to become even more insensitive to the action of your hands as you apply the reins.
For me, if I have a horse the is not paying attention to the bit and decide that a change of bits is in order, rather than choose a sharper bit, I will choose a heavier bit (my tack box is full of bits made of German silver :)). This has the effect of increasing the horse`s awareness of the bit without increasing the horse`s discomfort with the bit.
When riding in normal riding conditions, you want a type of head gear that will allow you to cue the horse through the reins. Reins are not for pulling on, they are for holding. And if, in regular riding situations, you find yourself (or your horse) pulling on the reins, then you are not communicating with your horse through the reins, and they have lost their true purpose.
But what about abnormal riding situations?
Many people have said, "I`m not talking about regular riding conditions, I`m talking about emergencies." Indeed, in an emergency (when a horse "checks out" for whatever reason: spook, etc.), it may be necessary to do more than just "cue" your horse through the reins in order to get his attention. (Just as, in certain emergencies it may be necessary to yell at a person to get their attention) Some people have mentioned using a Pelham, and applying the curb rein; other snaffle riders say they turn their horse in a circle by pulling on the rein hard enough to turn the horse`s neck to the side (this, incidentally, doesn`t always work. Just as any horse can run through any bit, it is also true that virtually any horse has a neck that is strong enough to resist the pull of the rider`s hand).
In an emergency, what you want to be able to do is get your horse`s attention so that you can then "cue" it through the reins the way you normally would. In my experience, a sharp jerk on both reins of a snaffle (you know, that old nut cracker action) is plenty "painful" enough to get the attention of just about any horse--as long as you don`t make a habit of doing this so that the horse has learned to ignore it. THIS is the reason that you don`t want to use a sharp bit on an unresponsive horse--because if you do, you will be teaching your horse, in its regular riding, to ignore sharp actions of the bit. THEN, when you have a true emergency and you NEED to get your horse`s attention. . . you can`t; he has long since learned to ignore discomfort with the bit (or whatever you choose to use).
But to extend my "communicating with people" example. Just as you may need to yell at somebody to get their attention; after you have their attention, you now want to communicate with them quietly. So it is with horses, in an emergency you may need to do something to get your horse`s attention (a sharp application of a curb rein on the Pelham can do it; a sharp application of both reins of a snaffle can do it; literally yelling at the horse--as in using your voice--can do it). If the horse continues to ignore you after you have the horse`s attention--then your "bitting" problems are training problems, and you have to go back to teaching your horse the language you want use to communicate through your hands.
I have never yet ridden a horse that cannot easily be trained to respond just fine to a simple snaffle bit, in all situations. And a simple snaffle bit provides me with sufficient precision and variety of communication to enable me to ask the horse to do anything I would want it to do for going down the trail or for going over jumps.
If I were going to move a horse into the upper levels of dressage where great precision and subtlety is required in order to get the horse to perform extremely complicated maneuvers, then I would advance to a double bridle. However, I can think of no other riding discipline that requires this much subtlety and variety--and certainly not endurance riding.
Additionally, I have never yet met a horse that cannot eat a drink with a snaffle bit it its mouth.:) The only situation where I felt it was warranted to remove the bit from my horse`s mouth for his comfort was at the Death Valley Encounter when the temperature was so cold that I felt guilty having that cold piece of metal in his mouth that conducted the cold with every moment--so I rode him in his halter. Perhaps, if I lived in a colder climate I would concern myself more about having a metal bit in my horse`s mouth, but I don`t.
All that said, this doesn`t mean that I don`t ride horses in other types of head gear. I have a young Paso Fino that I ride in a leather bosal who is the most sensitive horse that I have ever ridden, and she will respond to just the slightest twitch on the rein and the slightest pressure on the seat bone. I have another young Paso Fino that I ride in a leather bosal with a second rein on a curb bit who is also light, responsive and easy in hand. I have an old mustang that I ride in a low port curb bit. He simply, has never been taught to go in a snaffle, and he clearly has been taught to respond to a curb (neck rein and all). If he were mine, I would take the 6 months to retrain him to a snaffle, but he is not mine, and he is adequately trained to a curb so that his owner (with a little schooling about the proper application of a curb) can get him to do what she wants him to do as she goes down the trail (although he did bolt with her a couple of weeks ago and she got dumped--so SHE had a lesson on how to properly use a curb bit on a trained horse in an emergency).
I am sure that there are a multitude of horses out there who have been trained to respond to all kinds of different head gear. However, when you start having "problems" (i.e. the horse clearly hasn`t been trained to that kind of head gear), the simplest thing to do (for both you and the horse) is to go back to a simple snaffle; as it has been my experience that a simple snaffle bit provides the clearest and most uncomplicated form of communication.
kat, Orange County, Calif.
p.s. All this entirely begs the question of two important aids that we as riders have available for communicating with our horses: the leg aid and the weight aid. If you don`t have the ability to properly use these, you will never be able to "control" your horse. Though horses can be taught to "follow their nose" this is something that they must be taught. And if they haven`t been taught this, then all the head gear in the world isn`t going to do you any good, because even the sharpest and most severe head gear in the world only gives you "control" over the horse`s head--you still don`t have any control over the part of the horse that you are riding, which is the body. Incidentally, this is why there is more to riding than "just sitting there."