A leverage bit is any bit that amplifies the pressure applied by the rider’s hand through a mechanical advantage created by shanks or purchase arms extending above and below the mouthpiece. Unlike a direct-pressure snaffle — where the rein effect acts directly on the mouth — a leverage bit uses the shanks as levers, engaging poll pressure, chin groove pressure, and mouth pressure simultaneously. Understanding how leverage works is essential before using these bits, as the amplified effect can be severe in the wrong hands.
How Leverage Bits Work
The mechanics are straightforward: when the rein is drawn back, it acts on the lower shank, which rotates the bit in the mouth. This rotation applies pressure to the bars and tongue via the mouthpiece, poll pressure via the headpiece, and chin groove pressure via the curb chain or strap. The ratio of upper shank (purchase) to lower shank length determines the leverage ratio — a longer lower shank produces more leverage for the same rein movement.
A bit with a 2:1 purchase-to-shank ratio will apply twice the pressure at the mouth for every unit of rein pressure applied. A 3:1 ratio triples it. This is why leverage bits demand a rider with soft, still hands who can communicate in fractions rather than in bulk movements. Used by a heavy-handed or unbalanced rider, the amplification works against the horse — escalating pressure beyond what was intended and potentially causing pain or resistance.
Common Types of Leverage Bit
The Pelham is one of the most commonly seen leverage bits in British equestrianism. It is designed to replicate the action of a double bridle — applying both snaffle and curb effects — but using a single mouthpiece. It is used in showing, hunting, and by some combination riders. The Kimberwick (or Kimblewick) is a milder leverage bit with limited shank movement, popular for horses that need a little more control than a snaffle without the full action of a Pelham.
Western-style curb bits — including shanked patterns used in reining, cutting, and general western pleasure — are leverage bits, often with longer shanks and a variety of port heights to vary tongue versus bar pressure. The degree of leverage varies considerably across western bit designs.
For more on bit mechanics and fitting, see our entry on snaffle and our overview of double bridle use.
The Role of the Curb Chain
The curb chain is integral to the function of a leverage bit. It sits in the chin groove and becomes active when the shanks are drawn back — providing the fulcrum against which the lever acts. A correctly fitted curb chain lies flat, engages at approximately 45 degrees of shank rotation, and distributes pressure evenly across the chin groove. A chain that is too tight applies pressure too quickly and too harshly; one that is too loose allows excessive shank rotation before engaging, which can cause a jerky action.
Curb chains can be replaced with a leather curb strap for horses with sensitive skin, or with a rubber-covered chain for intermediate firmness. The BHS guidelines on bitting advise checking curb chain fit as part of routine tack inspection.
When Are Leverage Bits Appropriate?
Leverage bits are appropriate for educated horses ridden by experienced riders with independent hands. They are not training bits — they should not be introduced to young or green horses. Their purpose is refinement: allowing greater communication with less physical effort, not overcoming a strong or resistant horse through force. Using more bit to compensate for training gaps is a common and counterproductive mistake.
Competition rules vary. In affiliated dressage, leverage bits are restricted to the double bridle used at medium level and above. British Showjumping rules permit certain leverage bits. Always check the current rules for your discipline before competing.
Frequently Asked Questions
Is a leverage bit harsher than a snaffle?
It can be, depending on the specific bit and the rider’s hands. The mechanical amplification of pressure means that careless use causes significantly more discomfort than a snaffle used badly. However, a leverage bit used by a skilled rider with sensitive, following hands can produce a very light, refined contact that a strong horse in a snaffle would simply pull through. The question of harshness depends as much on the rider as on the bit itself. An experienced equine dentist or bitting specialist can help match bit choice to horse and rider.
Can a leverage bit be used for jumping?
Yes, and many horses are jumped in Pelhams or Kimberwicks. The key consideration is that over fences the rider’s hands inevitably move — a following contact is necessary to allow the horse to use its neck. A leverage bit amplifies any unintentional hand movement, so riders who jump in leverage bits need a particularly secure, independent seat. For cross-country, where sudden stops or refusals can jolt the rider’s hands, the consequent sharpness of a leverage bit should be considered carefully.
How do I fit a leverage bit correctly?
The mouthpiece should sit in the same position as a snaffle — resting on the bars without wrinkling the corners of the lips. The shanks should hang vertically when there is no rein pressure. The curb chain should lie flat in the chin groove and engage when the shanks are drawn back to approximately 45 degrees. Allow one finger’s width between the chain and the chin groove when the shanks are vertical. If in doubt, consult an appropriately qualified saddle fitter or bitting specialist — fitting leverage bits correctly makes a substantial difference to their action and the horse’s comfort.