Proper Bit Fit: Tom Thumb vs. Shanked Snaffle

To continue our series on bit fit, we will talk about the shanked snaffle. The shanked snaffle is used as a transition bit from a regular snaffle to the solid curb bit. This bit is a favorite for trainers and is used in a variety of western disciplines.
The shanked snaffle's effectiveness and ease of use is directly correlated to quality of the bit. A cheap variation of this bit is called the Tom Thumb bit.

Tom Thumb Bit
Picture from prochoice.com

As you can see from this bit is extremely straight from the purchase through to the shanks.
The purchase is the part of the bit that is above the copper mouth piece that attaches to the bridle. The shanks refers to the part of the bit that is below the copper mouth piece to end of the bit that attaches to the reins. The Tom Thumb bit often does not have a curved mouth piece that offers the horse tongue relief; because of this, the bit tends to sit awkwardly in the horse's mouth, often rendering the horse more pain or causing the bit not to be as effective. Due to its design with the broken mouth piece, this bit has a nutcracker effect on the mouth which is multiplied by the chin strap.

Now we will examine a higher quality form of the shanked snaffle.

View one

View two

What we notice about this bit that differs from the Tom Thumb is the mouth piece is slightly curved allowing for it to sit more naturally in the horse's mouth. The shanks of this bit are also slightly curved also to allow the bit to sit naturally while being more effective to cue the stop. This bit also has a better differentiation from the mouth piece to the shank. Being two separate pieces helps when the rider needs to go to two handed to help the horse learn neck reining. The TomThumb is one solid piece, which hurts the bit in its effectiveness. Because this bit is a transition bit from the snaffle, which is primarily used with two hands to a curb, that is used for neck reining, it is important that a trainer can switch between the two. You can see with this bit above that the mouth piece can slide up and down. This allows this bit to have a "gag" effect that signals to the horse that the chin strap is about to engage. The Tom Thumb does not have this feature.

Horses are taught by pressure and release. The higher quality the bit, the quicker the release of pressure should be. The bit in the second set of pictures slows the engagement of the chin strap allowing the horse to be signaled to stop before pressure is applied. This bit also allows for the quicker release of pressure rewarding the horse for the stop and for listening. Tom Thumb bits do not allow for a pre-signal nor do they allow for a quick release of pressure which deaden the horse's mouth to pressure.

Tom Thumb in a horse's mouth

In this picture you can see that although the reins are loose and relaxed the chin strap is still engaged causing pressure in the horse's mouth.

Better bit in horse's mouth. Relaxed

Chin Strap view. In relaxed position, chin strap is not engaged. 

With the higher quality bit, when sitting relaxed in the horse's mouth, the chin strap is not engaged, allowing the bit to sit comfortably in the horse's mouth. You want the purchase to align with the line of the horse's mouth and be a seamless transition from mouth, to bit, to bridle. As you can see with the higher quality bit. Look back up to the TomThumb, the bit is almost sitting perpendicular to the line of the bridle and mouth, this causes the chin strap to be engaged.

The quality of your bits are very important to the happiness and ease of training that horse encounters. Skipping out with a cheap bit can cause your horse pain leading to a variety of problems such as but not limited to: head tossing, holding head up to evade pressure, running through the bit, rearing, bucking, chewing the bit, putting tongue over bit, refusing to be bridled, and a variety of other problems. Cheap bits can lead to pinching of the lips of the horse, and/or rubbing the side of the mouth. By buying bits made with better materials or better design can change the way your horse rides or even how well they can be trained. It is important to transition to more severe bits slowly and when your horse is proficient with milder bits. Your training and transitioning bits are the most important bits to a training program, no matter the discipline. More important than quality of the bit is the fit. By remembering that two fingers between the headstall and cheeks, with one wrinkle in the corner of the mouth is the general rule for bridle fit. You should always be able to get two fingers between the chin strap and chin. Too tight and the more pressure the horse feels in the mouth. Too loose, the more you have to pull before chin strap is engaged. Remember to always check your tack for dry rotted parts or parts that has come loose. Nothing ruins a ride like your horse running away without a bit or way to stop them!

Happy Trails.






Written by: C