Choosing the right bit is essential for horse health, safety and performance. The bit acts as a communication channel between rider and horse, so it is crucial that it fits the anatomic mouth conformation of each individual animal.
The simplest of all bits is the D-bit, commonly known as a snaffle bit. It consists of a mouthpiece that sits in a ring that is attached to the bridle with a D-shaped chain. The snaffle bite is often recommended for horses that have sensitive teeth, as it applies less pressure to the bars of the mouth than other types of bits.
Single-jointed mouthpieces – common in snaffle bits – are considered mild, as the joint only affects a small area of the tongue. However, they are not a good fit for horses that have low palates, as they will experience more tongue pressure when the reins are pulled. Double-jointed mouthpieces are more gentle, as they have two joints in the center that reduce the nutcracker effect and spread the pressure more evenly.
A flexible Mullen mouthpiece is another option that can be used as a mild bit. The flexible design allows the mouthpiece to bend slightly when the reins are tightened, distributing the pressure evenly across the whole surface of the tongue and getting stronger towards the tongue edges. Mullen mouthpieces are often well accepted by horses that do not get along with jointed bits.
Twisted bits are considered a more severe type of bit, but they can be very effective in corrective riding. These bits have twisted edges that create pressure points on the bars of the mouth. Examples of this type of bit include the Slow Twist, Corkscrew and Double Twisted Wire bits.
The ring bit – also known as the hammer or square-mouthed snaffle – is the most common type of ring bit. The ring of the bit extends from the mouthpiece in a ring shape, and is surrounded by a square-shaped bar that rests against the lower jaw. This is the type of bit that Funny Cide raced in during his Kentucky Derby and Preakness victory.
The ring bit is a good choice for horses with large tongues because it allows them more room in the mouth to move. It is often used to help correct bucking or rearing issues, and it can be helpful in training young, untrained horses. You can use a commercial bit sizer to determine the proper fit of your horse’s mouth, or you can mark your own bit length with a piece of string that you slide into your horse’s mouth (mark the spots on the string where it meets the corners of his mouth) and then lay that against a ruler. Depending on the type of bit you are selecting, you may want to add 1/4 inch to your bit size measurement. This is to ensure that the bit is not too long and causes rubbing at the corner of the mouth.