Single Joints vs Double Jointed Bits
Single Jointed Bits
Single Jointed bits forward the riders rein aids to the tongue-edges and the lower jaw bones. When giving rein aids the bit forms a V-shape and exerts pressure to the tongue edges. This can be described as “nutcracker” action. The V-shape may cause problems for horses with a flat palate and small oral cavity or if you choose a too large bit size. In these cases the eye of the joint might press into the sensitive palate and cause bruises or injuries. The quality of the bit will also play a factor in this part, a well made and well balanced bit will not "nutcracker" as much as a bit is off on the balance.
Standard single jointed bits have a production related characteristic: one part of the mouthpiece is longer than the other which results in stronger influence on one tongue edge. To prevent exerting uneven pressure in the long term you should turn the bit around periodically.
Double-jointed bits distribute the pressure from rein aids more evenly and over a wider surface onto the tongue, without exerting pressure to the sensitive palate. All double jointed bits from SPRENGER made of SENSOGAN and AURIGAN are anatomically adapted to the horse’s mouth. The middle link has been shortened and angled forward in order to make it more comfortable for the horse and to achieve the best possible effect.
Common double jointed bits have a wider middle link. The eyes of the link are not angled and lie upright between tongue and palate and can, therefore, cause problems because they might press into the tongue or the sensitive palate, especially when the bit is chosen too thick for the shape of the mouth.
The patented KK ULTRA bits have been developed based on scientific research. They reach their unique and precise effect due to the shortening and 45° angulation of the middle link. This specific adaption to the horse’s oral anatomy makes a noticeable effect in comparison to using common double jointed bits. The bit is gentler to the horse’s mouth and allows the rider to give precise but soft aids.
Mullen Mouth - No Joints
Straight and rigid Mullen Mouth bits exert steady and even pressure on the complete tongue. In comparison to jointed bits, a straight bar exerts less pressure on the tongue edges. The stronger the rein aid the more pressure is directed onto the tongue and lower jaw bone. Recommended for horses that evade the rein aids and tend to get strong. In contrast to bridles with additional lever action on the poll (e.g. Pelham or Kimblewick), Mullen Mouth bits can be used for horses that dodge downwards and lean on the bit.