The curb strap on your bridle can slam into position to stop your horse much like the arms at a railroad crossing drop to stop your vehicle. At first glance, either action seems abrupt, yet neither comes without forewarning.
Before the crossing arms drop, lights flash and bells peal, and you see a speeding train. Likewise, a well-made bit sends your horse built-in presignals, warnings that change is imminent before the curb strap grabs his chin. These systematic presignals give your horse ample opportunities, or signal time, to respond before the curb strap takes hold.
In addition, says Les, a bits signal time, leverage, power and your hands, as well as something called preload, can affect a horse's response time. Vogt should know. The lifelong bit maker and horseman has used his wares to claim 15 reining and cow horse world championships.
Theres no comparison to really explain the value presignal and all those things have in enhancing your ride and the pleasure of communicating with your horse.
Although people thing of a horses mouth being about 5 inches wide, the bars are only about 2 - 2 1/2 inches apart and on top are shaped somewhat like a fish's back. The inner sides of the bars are bone and skin, but the outer sides have a spongy, fatty-type material under the skin.
If you set a bits mouthpiece across your fingers or the palm of your hand, the shanks gravitate forwards, rather than hang perpendicular to the ground. This may not seem balanced but this gravitational effect is what Vogt refers to as preload. A thoughtful bit design creates preload by putting weight in the cheek, behind the mouthpiece, so that gravity swings the shanks forward.
This allows the bit to unload-release pressure-whenever the rider releases the reins. Pulling the reins loads the bit.
The quicker a bit unloads, the quicker you release your horse when he gives a positive response, the quicker he understands and the better your communication. You want all the preload you can get. You actually can feel it when you release the bit to unload and your horse is rewarded.
A bit works by contacting different pressure points for which its presignals are designed. The presignals go from one pressure point to the next, Vogt says
Pressure point 1 includes the horses lips and the corners of his mouth, the first areas where he feels a change
Pressure point 2 is the horse's tongue, where he feels the bit mouthpiece move.
Pressure point 3 may be the horse's palate, depending on the bit design
Pressure point 4 is where the mouthpiece, more like a straight bar at either end, loads straight down onto the bars of the horse's mouth.
Pressure point 5 affects that spongy tissue. A more triangular shaped, open port rides on the tongue, but as the bit rotates it puts pressure on the fatty tissue. The more the mouthpiece rotates, the more it wedges against that outer layer
Pressure point 6 is under the chin where the curb strap rests to give the final signal for your horse's response.
Why is presignal important in a bit? Put yourself in the horse's place. If someone says "whoa" and twists your ear hard each time, you soon jump at the word, associate it with pain. Then you hold your breath and brace through your neck. When a horse braces through the neck, all your training or performance capacities go away. You can never maximize your horses abilities unless his neck is resistance-free, so there can't be any shock to the communication. That communication comes in sequence with its presignals in exactly the same order every time the bit moves. Its a wonderful machine.
Any broken or hinged spot in a mouthpiece, including where a bit swivels on the cheeks, gives a presignal. Although some bits have more presignals than do others, the presignals always occur in a systematic order.
Presignal 1 occurs when you pick up the reins. Your horse feels that slight movement. Preload gives you that feel, as does the weight of decent reins. If you have sensitive, educated hands at all, you feel that weight move, which gives your horse plenty of presignal
Presignal 2 occurs when your horse feels the bit cheeks move. Vogt prefers a bit fairly loose where the cheeks mount to the mouthpiece. The horse feels the 'click-click' as the cheeks move. That's not a really sophisticated signal, but definitely exists. Loose cheeks provide more presignal and are more forgiving than is a solid bit, which causes things, good and bad, to happen fast.
Presignal 3 results when the mouthpiece rotates. Otherwise, it rests on your horses tongue. For example, when a triangular shaped low port mouthpiece rotates, your horse feels the port leave his tongue and move toward the spongy tissue on his outer bars. Your horse could respond to presignal 3. If he is educated to the bit, he knows that presignal 4 is coming...
Presignal 4 happens as the mouthpiece gradually wedges against that fatty tissue outside his bars. The more your horse fails to respond, respect or acknowledge your request, the more the mouthpiece rotates and the greater the pressure on the outside bars. Your horse has fair warning, signal after signal. He can respond now or feel the curb strap.
Presignal 5, the final one, is the curb strap grabbing your horses chin, telling him he should have listened previously. Many bits work primarily off the curb strap, Vogt explains, which isn't so great because there's little presignal. With a solid grazer bit, for example, everything happens abruptly through the curb strap. The horse doesn't feel that presignal sequence. A horse can feel those presignals, Vogt says, even when your hand is faster than it should be. That's the glory of a really good bit compared to one that 'slaps' a horse.
Power is in the bit mouthpiece, which should attract your horse's attention and respect. Otherwise, Vogt says, "your student is looking out the window. There is no respect"
Vogt references a statement he frequently hears from people about wanting to "save a horse's mouth". He then describes a graph with a line running from the bottom left diagonally to the opposite corner. A mild mouthpiece at the bottom says "no respect", a medium mouthpiece halfway up the line says 'some respect", all depending on a horse's attitude, tolerance and attention span. Near the top of the line, the graph reads "a lot of respect" but just past that point, the red zone says "fear"
"You want a lot of respect," Vogt says. Don't begin your bitting process with the lowest-power mouthpiece unless that's all your horse needs to give you maximum respect; otherwise, you're giving your horse a choice of pushing on the bit or respecting it. That shouldn't be a choice and it isn't what you want. You want a mouthpiece that your horse responds to with respect, not fear.
Once you make a choice about the particular mouthpiece power your horse needs, you can think about other things, such as the leverage and presignal you like.
The above is an excerpt from an article by Les Vogt that an old expat was kind enough to type up and share.