Bit Selection for Reining

The Snaffle — Foundation Tool

Every reining horse begins its training in a snaffle bit — typically a smooth, thin-shanked o-ring or D-ring snaffle with a broken mouthpiece. The snaffle provides direct pressure: when the rider picks up the left rein, the left side of the horse's mouth feels pressure. This directness makes the snaffle the ideal teaching tool because the horse can feel exactly what is being asked and understand immediately when the pressure releases upon the correct response.

Al Dunning, who has won more NRHA Open Futurities than any trainer in history, begins all his reining prospects in a snaffle and keeps them there until specific criteria are met. The horse must be reliably steering with neck rein pressure, stopping off the seat and voice consistently, and showing lateral softness on both sides before a shank bit is introduced. There is no timeline for this transition — only readiness criteria.

The Hackamore

Some trainers use a mechanical hackamore or a bosal as an intermediate step between the snaffle and the shank bit. The hackamore works on the nose, chin, and poll rather than the bars of the mouth, and can be useful for horses that are mouth-sensitive or for adding lateral suppleness without direct mouth contact. Not every trainer uses a hackamore, and it is not required in the standard snaffle-to-shank progression — but it is a legitimate option worth understanding.

The Shank Bit — Finishing Tool

The shank bit — also called a curb bit or leverage bit — amplifies rein pressure through mechanical leverage and poll pressure from the headstall. A small movement of the rider's hand produces a larger effect on the horse than the same movement in a snaffle. This is exactly why the shank requires a horse that is already confirmed in its responses: the amplified pressure must be met with an already-established response, not used to force a response the horse does not yet understand.

Common shank bits in reining include the correction bit, the cathedral, and various high-port designs. Port height, shank length, and mouthpiece diameter all affect the bit's action and severity. Longer shanks create more leverage; higher ports create more palate pressure; thinner mouthpieces concentrate pressure on a smaller area. When in doubt, choose a bit with a shorter shank and lower port and work toward a more refined tool as the horse's training confirms it.

Signs You Have Chosen the Wrong Bit

If your horse opens its mouth, tosses its head, braces against rein pressure, or becomes dull and unresponsive in the bit you have chosen, the bit is wrong — either too severe, poorly fitted, or being used on a horse that is not ready for it. Return to the previous bit, identify what training gap exists, and address that gap before reintroducing the more advanced tool. The bit is never the solution to a training problem.

Watch & Learn

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Introducing a Young Reining Horse to the Snaffle — Herm Petroll

Petroll Reining

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Transitioning From a Snaffle to a Leverage Bit — Ken McNabb

Ken McNabb Horsemanship

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How to Use Bits Properly — Snaffle to Shank Transition

Western Bit Training

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Snaffle Bit Fitting Tips for Performance Horses

Western Tack & Training