Choosing a bit, should start with an assessment of the horses external and internal facial anatomy, which is crucial to selection process. This will determine what shape will sit comfortably within the mouth and what actions will offer clear signals and which cheekpiece best supports the riders needs.
The result you are hoping to gain should be that the horse be more relaxed and willing to accept the contact and more readily responsive to what you are asking.....it should simply be easier for both!
Key features that you should to take in to consideration when selecting a new bit are, whether the horse has - thick fleshy lips, short from front of lip to corner. Large tongue, small, low narrow top palate space.
It is also essential, that the horses teeth and saddle have been checked by the appropriate professionals, ideally within 6 months. Also it is preferable that the horse has been seen by a qualified physio chiropractor or Osteopath within 3 months to eliminate any soreness or tightness as these elements can have a negative impact on improving on your bit. These sore/tight areas are often where improvements will be noticed after a bit change, with a period of a more relaxed and less tense and evasive way of working with the in some cases the reoccurring soreness can be a direct result of bit evasions and also gives you peace of mind that you are not asking for an improvement that the horse is physically unable to offer.
Knowing the horses recent Bitting history, can be helpful toward deciphering what the horse is finding difficult to accommodate or understand.
If you have a mouthpiece action or shape that the horse is unable to accept, by adding a cheekpiece such as a leverage cheek only serves to intensify the action of the bit that the horse has already tried to demonstrate by evasion it can’t understand or cope with. Any bit choice should not be viewed as a quick solution to ‘get an outline’ it should only be there to suggest and encourage the horse to stretch across its back and create a soft but consistent contact achieving a true connection and using its abdominals to support self carriage. The bit should complement the age, level of education and physical form and strength of the horse, combined with the riders experience. Objectives should be realistic with regard time to transition to a new bit and changes within the muscle groups not putting the new working muscles into fatigue.
Horses often prefer the bit to be stabilised by a form of cheek
Sitting snugly into the corners of the mouth and this can vary quite considerably from horse to horse, depending on mouth conformation i.e. length from front of lip to corners of mouth. Top palate space (similar to the roof of our mouth) where the tongue rises when swallowing, lifting the bit with the tongue movement. If a bit hangs too low it can create a busy/fussy reaction to the bit and if it bangs onto the flat wavy area top jaw they may become chompy.
I find that most horses like the bit sat a little higher than expected so it gives a better clearance for the tongue. There should be little or no gape in the cheekpiece of your bridle when the height of the bit is correct. When fitting any form of loose ring you would choose a 1/4” larger so that the horses lip does not sit over the hole as it’s possible as the ring rotates it can draw the lip into the hole and result in pinching.
Personally I tend to choose a smaller diameter bit ranging from 12mm, 14mm and for larger horse 16mm. This makes the bit less intrusive and easier to keep tension out of the TMJ so the jaw can remain relaxed.
Evasions can manifest in many different forms - head high, head low, tongue out or over the bit, stiff through the neck, snatching busy fussy with the mouth, spooky and inattentive, unwilling to accept a contact - evasion is the only voice the horse has to demonstrate he can’t cope or understand a bit. Unfortunately in many cases, then a tight restrictive noseband is used to remedy the problem which only serves as a sticking plaster effect. Where there is evasion/resistance to a bit it will have a negative knock on effect throughout the body and performance.
Too much tongue pressure or pinch from a bit leaves the horse no choice other than to remove its tongue either by putting over the bit or lolling to one side. Most commonly I see that they retract their tongue high into the jaw to relive the discomfort. Once the horse has found this relief, it will start to habitually resort to doing the same each time its ridden and then becomes the norm. The effects are stress on the lower jaw, stiffness through the neck and restricted movement. Horses will clamp their teeth one side to reduce bit movement and discomfort. Some will be rigid through the jaw to prevent movement these often result in the need to head shake to release the muscles in the jaw and poll area.
Bit manufactures are really moving forward with shape and contouring bits to compliment horses anatomically. Materials and build quality are also greatly improving and many of the larger more well known brands invest much research into their products. It is possible these days to get some very good copies at reasonable prices but I would say generally you get what you pay for and safety should paramount. The more well known brands also provide a synopsis of what they believe their bit designs can achieve which can give you a good inclination. Personally I find that until you fit the bit to the horse you can never be quite sure as you also need to consider the type of rider and circumstances that makeup that particular partnership. In recent times bits command such high prices, it make sense to seek a professional well established Bitting consultant/fitter you can never be quite sure as every rider has a unique style of riding and different degrees understanding and requirements.
Bit bank services are very useful to give the horse and the rider a period of adjustment to a new bit to consolidate the improvements and give the horse time to adjust physically.
If you are always experiencing the same evasion or your horse becomes reluctant to being bridled or your not progressing or simply having a battle each time you ride - don’t keep persisting it’s damaging to the horse and soul destroying for the rider and only cements an incorrect muscle build, tension/soreness.
Although Bitting is not the only answer, it is the piece of equipment situated in the most sensitive area of your horse, that you expect the most answers!