The "One Hander" Bit is an interesting contraption, designed to teach neck-reining or for use when direct-reining is not only unnecessary, but in fact undesirable (for example, in events such as roping). The mouthpiece is adjustable, with a rotating port that screws into and out of the rubber-covered cannons, thus changing the overall width. Bit guards are built in. The shanks have a spring-loaded design which slows the action and absorbs some of the force of the reins, thus making the bit milder than it might otherwise appear at first glance. The shanks also bend in every direction, so that pulling laterally really results primarily in a backward force on the bit (thus rendering direct-reining a fruitless task). It is therefore impossible to pull the mouthpiece off-center in the mouth, and the bit is very forgiving of mistakes made by the rider's hands, either from pulling too abruptly or pulling unevenly. My mare in the video was only flinging her head because I was using more force on the bit than I generally do in order to better illustrate its action.
This is a cool little bit: certainly not appropriate for all circumstances, but nice to have around for use on the right horse and right situation. It's also fairly collectible, being hard to come by since the company producing it was disbanded.
Here is a short video demonstrating the action of the Myler
Pelham with the 41PB (ported barrel) mouthpiece, which illustrates Myler's
patented "independent side movement" very well. As is plainly visible in the first video
segment, the entire mouthpiece rotates, bends, and folds about itself, creating
a very flexible, fluid motion in the horse's mouth. Traditionally, a Pelham is an English
leverage bit designed to be used with two sets of reins (one on the snaffle
ring and one on the curb), but this is not necessary if only curb action is
desired, and indeed, I find that this mouthpiece is more favorable when paired
with a curb than as a snaffle.
In the second video clip, I have placed the Pelham in my
mare's mouth and adjusted it as I would normally ride (yes, the extra curb
length should ideally be cut off, but I digress). It was difficult to photograph--and even
harder to film--the action when on the horse, so I will attempt to explain the
two pictures.
One point that is often made against these sorts of bits is
that the edges of the mouthpiece at the bottom of the port are squared off,
albeit smooth. The concern is that the
small surface area here could be damaging to the tongue. I found, and attempted to photograph, how the
bit rotated and, when engaged and applying downward pressure, only the flat,
non-squared portion of the mouthpiece was pressed up against the tongue and
bars. This effect may be somewhat
dependent on how the bit is adjusted, but my experimentation was quite
sufficient for me to declare, at least in this case, that the squared edges are
a non-issue. (You might also note that
in the first photo, in my efforts to get my camera in place and hold the mare
steady, I have pulled the bit sideways through the mouth--when riding, so much
lateral pressure would not normally be applied, so the bit would sit more
centered. Additionally, please forgive
the chewed grass chunks!)
In the second photo, I have attempted to illustrate the
action of the port. Again, the cannons
of the mouthpiece have rotated so that the flat part is parallel to and against
the tongue. The tongue is filling the
gap in the "tongue relief" section, where the cannons curve upwards
into the joint and the port arches further.
The top of the flat port has come into contact with the palate, which is
naturally low in all horses. However,
the primary force of the bit at this point, with a moderate amount of pressure
on the rein that would mimic a normal riding cue, is directed downward still,
against the tongue and bars. While the
port is hitting the palate (and disbursing pressure over a wider area than a
rounded port would), it is not pushing up against it so hard as to create undue
force, and the mare seemed completely unperturbed. The curb is hobbling the bit to prevent the
port from moving further and, indeed, this is a relatively low port to begin
with.
Cues from one rein are easily isolated, so direct reining is
easy and clear with this bit. In
summary, I knew there was a reason I liked this mouthpiece....
Presented here are three different types of curb bits: A Myler Kimberwick, an Argentine snaffle, and a long shank Sweetwater. Each has been adjusted on the horse exactly how I would do so if I were going ride. I am pulling on the reins from the angle that would occur in the saddle, so that everything mimics the riding condition as much as possible. The point of this video is to show the relative degree of poll pressure (or lack thereof) that occurs with each of these bits. Poll pressure is often touted as an inherent component of the action of a curb (leverage) bit, but this is not necessarily the case, depending on the exact mechanics and design of the bit, the adjustment of the curb chain and headstall, the degree and angle of contact on the reins, and the horse's head position. While it is difficult to capture on camera exactly what is going on, I have tried my best, and am providing this description to accompany the visual.
First, please note that in order for poll pressure to be an action of the bit, the cheeks of the headstall must tighten, as they are the connecting pieces between the bit and the crown (poll). If the cheek pieces are slack, or if they do not further tighten from their default setting when rein pressure is applied, then poll pressure cannot be part of the action of the bit.
For the Kimberwick, note that the cheek pieces grow very slack as increasing rein pressure is applied. What is happening is that, while the bit is indeed rotating and applying curb pressure, it is also rising in the mouth. The shanks are short and the curb activates slowly enough to allow the cheek pieces to loosen (you can see them bowing out). Poll pressure actually *decreases* from default when this bit is activated.
Next, look at the Argentine. It is difficult to observe what is happening with the action here, and there is certainly no visible bowing of the cheeks, as with the Kimberwick. However, if you look closely, you can see that the cheek pieces remain completely in place and do not appear to have any additional tension placed upon them. The purchase ring of the bit slides freely over the cheek piece's attachment--it does not grab and pull it forward, so the crown is not activated. I did place my hand under the crown piece of the bridle while pulling firmly on both reins, and I was unable to feel any tightening, even with considerable force applied to the bit (and a thankfully tolerant horse).
Finally, consider the Sweetwater. This is a hefty, severe curb bit, so I did not pull as hard on the reins. Still, while it is hard to visualize in the video, you might note that there is indeed some tightening of the headstall's cheek pieces. I placed my hand under the crown and was able to feel poll pressure that increased as I applied more force to the reins.
In summary, poll pressure is certainly a component of the action of some curb bits in some scenarios, but it is not a foregone conclusion and its severity depends on multiple factors.
