To select curb bit
There is no reason to look for extreme variations of the curb in your bid to improve your riding experience. Certainly there are lots of variations and it can seem impenetrable, but you can follow some simple ground rules.
If you are uncertain, you should first consult your coach or someone else you trust. What follows here is general advice; no guarantees!
As a first curb, I usually recommend the Portuguese curb. It works well on most horses and can be used alone, with two reins or together with a bradoon.
With the horse's reaction to this bit as a starting point, you can, if necessary, try other models.
Most horses get on well with a normal (low) port. Some horses, however, particularly those with a fat tongue, may find that a low port presses too much on the tongue. With these horses a higher port may be beneficial but make sure the chain is adjusted correctly; a loose chain that allows the curb to come on beyond 45 degrees to the jaw, could put the port into the roof of the mouth. If you notice that the horse feels dumb in his mouth with a normal port, or is anxious about his mouth (excessive, annoyed chewing) or he, hangs out his tongue, try a higher port. NB. There are not many horses who can tolerate a curb with no port at all!
When riding with two bits (curb and bridoon), the upper shank can be short, so the chain and the bridoon do not conflict in the corner of the mouth. When riding with the curb only, I recommend a longer upper shank, as there is no risk for the chain and the mouth piece to squeeze the corner of the mouth. I have seen many horses with sores in the corners of their mouth. If the upper shank presses against the cheek, you can easily bend it out in a vice.
The difference in length of upper and lower shank determines the "strength" of the bit. Big difference = sharp. At the same time, a long lower shank gives rider's hand more freedom of movement, as the hand must move further before the rein affects the bit. A long lower shank also offers the horse less room to move his head and this is a little more commanding.
inexperienced horse = short lower shank
experienced horse = long lower shank
NB. A short shank is not kinder if it is always fully applied!!
Apart from the length and angle (balance), the shape of the shanks make no influence to the effect of the curb ie. the S-shaped shank does not alter the function of the bit itself. Let taste prevail.
- Length of the mouth piece
Curb bits should be a “snug” fit in both corners of the mouth. It should not be possible to pull the curb bit out side ways! If the upper shanks pinch the cheeks or cheek teeth, (common on horses with short heads), they can easily be bent out on the iron and brass curbs. The stainless may be a bit challenging to bend as this material is so much harder.
I have not seen any major difference in function or the horse's acceptance of different materials. Let aesthetics prevail. Black curbs go rusty if stored in humid conditions or are not cared for. They must be wiped, not washed, and wiped with vegetable oil to reduce the risk of rust. You can also let them rust and get a beautiful pattern. The horse likes them anyway, as long as they are kept smooth. If they do go rusty, steel wool is a good tool.
All black bits can be slightly brownish.
Brass is a weak metal and can bend, so it must be handled with some care. It is not used for rough riding
A rigid curb works well for most horses but if the shanks can be turned, in the way of the Portuguese bit, there will be no real difference. There are also curbs where you can drag one shank backwards, against the rider, in isolation. Such bits are called correction bits among western riders. They make it difficult for the horse to get a good contact with the rider's hand, and should be avoided.
If you're holding a curb so the mouth piece is resting in your hand , let the shanks hang free, so you can see that they either hang straight down, or that the curb turns forward or backward. Normal horses need a curb that hangs straight down, while the horse that holds his head too low or the nose close to the breast (behind hand), usually prefer a curb where the lower shank is rotating forward (and the upper shank backwards). The academic curb and my S curb are of this type.
This test of the bit should be made without the chain.