Bits come in all sorts of shapes, sizes, styles and designs, and what suits one horse wont work as well for another.With such a vast range to choose from, deciding which to use is a complex task. However, it is also a very important one, as a bit is a vital item of tack (unless you choose to ride bitless).Before you put a bit in your horses mouth, you need to understand how it works. So weve put together this handy A-Z guide to bits to help you recognise all the different types and learn the action and affect they have on a horses mouth.What is a bit?A bit goes inside the horsesmouth and sits in the spacebetween their front andback teeth. They are usuallymade from types of metal such asstainless steel or copper, but they canalso be made from synthetic materialssuch as rubber (more on this later).The bit attaches to a bridle and the reins, and helps the rider control the horses speed and direction. Bits come in many styles and materials, which can make choosing the most suitable one for your individual horse confusing.How to choose a bitSometimes bitting is trial and error. You might ride in one bit for a few days before trying another, and it could take several rounds of this to find the bit that your horse is happiest in.Every horses mouth is different, so factoring their mouth conformation into your decision and choosing the best size for them is vital.Important things to consider before choosing a bit include:Size andshape of your horses mouthHowwell-schooled your horse isThe levelof your riding and how experienced you are. Do you, for example, have an independent seat?Theaim is to select the mildest bit that stillallows for clear communication with yourhorse.Bear in mind that a rider with softhands using a more severe bit will be akinder experience for the horse than arider with heavier hands using a soft bit.Its about getting the balance right for thetwo of you and finding it could meanenlisting the help of a bitting consultantor an experienced trainerwhose opinion and knowledge you trust.Types of mouthpieceThe mouthpiece isthe part of the bit that sits in the horsesmouth, and it comes in a variety ofdifferent types. These can be:Straight-bar mouthpiecesA straight-bar mouthpieceAs thename says, these are a solid bar of metalor other material such as rubber or plastic.Straight and rigid Mullen Mouth bits exertsteady and even pressure on the tongueand put less pressure on the tongue edgescompared to jointed bits.The stronger therein the more pressure is directed ontothe tongue and lower jaw bone.Mullen Mouth bitsThese horse bits can also be straightand flexible, or have a port. The latter hasno joint but does have a slight curvaturein the centre in order to accommodate thehorses tongue, meaning no pressure isapplied to it.Single-jointed mouthpiecesA single-jointed fixed snaffleSingle-jointed bits produce a nutcracker pressure in the horses mouth.Nutcracker action occurs when the reins are applied and the bit forms a V-shape in the mouth, applying pressure on to the edges of the tongue.Double-jointed mouthpiecesDouble-jointed bits have two pieces joined by a link, which distributes pressure from the rein aids over a wider surface area onto the horses tongue.Styles of double-jointed bits include ported (with a raised portion in the centre), French link, Dr Bristol and ball double-jointed mouthpieces. Each operates differently, with double-jointed considered milder than single-jointed.Bit textureA double-jointed mouthpieceBits come with different textures of mouthpiece, such as twisted or textured mouthpieces.Smooth mouthpieces are softer than textured or twisted ones.The thickness of the mouthpiece in terms of the horses comfort depends largely on the size and shape of the individual horses mouth. Generally, thicker mouthpieces are believed to be kinder than thin bits.Snaffle bitsSnaffle bits are one of the simplest bitdesigns, and consist of a mouthpieceand rings.The mouthpiece can be jointed,straight-bar or mullen mouth.Its oftenthought that snaffles are all mild bits, butthis isnt always true. While the pressure ismore direct in the snaffle, as opposed toworking with leverage, some mouthpiecedesigns accompanied by heavy hands onthe reins will make it more severe.There are several different types ofsnaffle bits:D-ring snafflesThe rings on a D-ring snaffle are D-shaped rather than circular.The shape does not allow the bit to rotate,and also applies some lateral pressure onthe horses mouth.Eggbutt snafflesEggbutts are mild as they donot pinch the side of the mouth. Themouthpiece does not rotate, which canfeel more comfortable to some horses.Full cheek snafflesA full cheekFull cheek horse bits have long arms on either side and the ring is attached to the arms. This helps with lateral guidance and keeps the bits position in the horses mouth consistent.It is often used with young horses to help teach them steering without the bit being pulled through their mouth.Loose-ring snafflesThe mouthpiece may slide on the full,loose ring, so that it rests in the mostcomfortable position for the horse, ratherthan being fixed in place, which canencourage the horse to relax its mouthand chew the bit.Hanging cheek snafflesA hanging cheekThese have single round cheek rings towhich the reins attach, while the bridleattaches to a piece about half an inchhigher than the ring, giving the bit a verymild amount of leverage (poll pressure).Loose-ring or fixed snaffle?Choosing between thesesnaffle types will comedown to what best suitsyou and your horsesrequirements.Loose ringsLoose ringstransmit the pressure ofthe reins directly onto thetongue and the lower jaw,without any leverage onthe neck. The moveablerings may help to slightlycompensate and balanceunsteady/inexperiencedrider hands too.The horsemay also be able toslightly lift the bit in theirmouth by stretching thetongue and evading toostrong a pressure fromrein aids in the short term.A loose ring snaffleLoose rings are suitablefor all horses doing allactivities, starting fromthe early days of theirridden career andonwards.Fixed ringsFixed rings alsotransmit rein pressuredirectly on to the tongueand the lower jaw withoutleverage on the poll, butthey do this in a moredirect way.Being fixed means these bits stay steady in the mouth, while smooth edges make it suitable for horses with sensitive mouth corners.A fixed ring/cheekpiece is often recommended for a horse that likes to play with their bit, giving the rider an unsteady contact, or who fall out on a turn or when approaching a jump.Horse bits: curbsCurb bits work by applying indirectpressure on the horses mouth. Thismeans you use less pressure on the reinsto reach the same pressure on the bit thatyou would with a snaffle.This makes itmore severe depending on how muchforce is placed on the reins.The length of the shank also increasesthe severity, as longer shanks mean morepressure on the horses mouth.Other than shank sizes, there aredifferent shapes as well. The straighterthe shank, the less warning the horsehas before the pressure hits it.Someare loose-jawed that is, they let themouthpiece rotate more while others arenot.Curb horse bits also come with a curb chain,which runs under the chin andapplies pressure on the chin groove.A Pelham with two reinsTypes of curb bit include:Weymouth curbThese are often part of a double bridleensemble (more on this below) and usually havea solid mouthpiece, either straight orwith a slight port. They are usedalongside a snaffle.PelhamThe Pelham is almost like a double bridlein that it allows for two sets of reins tobe used at once, but it is only onemouthpiece. Its often used to transitiona horse to a double bridle.KimblewickA Uxeter slotted kimblewickThese have a D-ring like the D-ringsnaffle, as well as a curb strap or chain.The further the rein slides down the ring,the more poll pressure is applied.A Uxeter slotted kimblewick has slots in the D-ring offering different holes to place the reins through. The higher the rein is applied, the less severe the leverage.Three pressure points of a curbHorse bits with a curb act on threedifferent parts of the horses head:Over the tongue into the bars Bylever action of the lower cheeks onthe poll Through the curb chainon the chin groove. Working in this way enables therider to give clearer instructionsand to have more control overstrong and powerful horses.However, a correct basiceducation and level of training(both horse and rider) is necessarywhen using these bits. A hand thatis too strong, for example, will beparticularly unkind if applied to abit with such leverage on the polland lower jaw.A curb chain guardis recommended, too, in order toprotect the sensitive chin areawhich is only covered by a thinlayer of skin.Horse bits: gagsA Cheltenham gagGags work like snaffle bits but offer someleverage. They apply some pressure on thehorses poll, depending on where the reinsare attached.Different types of gags are:Cheltenham gagA Cheltenham gag consists of a mouthpiece with two rings at either end, as in a snaffle, but each ring has two holes one at the top and one at the bottom through which the gag cheekpieces run in order to connect it to the bridle and reins.Dutch gagA Dutch gag with three ringsA Dutch gag (or three rings) bit consists of three or four rings.The big ring is attached to the mouthpiece, with one smaller ring on top to attach the bridles cheekpiece.There are then a further one or two small rings beneath the big ring.The reins can attach to any of the rings (but not the very top one) according to how much poll pressure you require.The lower the ring, the more leverage you have over the poll.How gags workWhen applying the reins to a gag, pressure is distributed from the tongue on to the lower jaw and the poll. This enables a rider to have more control over strong horses that evade the bit by putting their heads up, as the horse normally reacts to the gags leverage by lowering the head in order to avoid the pressure.This effect is even moresignificant in a three-ring gag, asthe leverage effect is increased bythe side part.Optimum effect isachieved by using two sets of reins:the main rein stays on the largestring, acting on the tongue andlower jaw, while the second rein ison a lower ring and can be used toapply poll pressure when required.Theseare best suited to experiencedriders with a sensitive hand.Double bridlesDouble bridles are made up of two bits: a snaffle in the form of a bradoon and a curb.The double bridle has the effects ofboth snaffles and curbs on the horse, withpressure on the bars and mouth from thesnaffle bit, and on the chin, poll, tongue,palate and bars from the curb.In the higher levels of dressage, the ideais to ride on the bradoon most of the time,engaging the curb only to encouragecollection, making it a useful tool forrefining control. In the wrong hands,it can be severe and harmful.If you havent seen it yet, we have more information about double bridles and how they work here.Use with cautionA Chifney bit is for leading horses onlyRemember, its not always as simple as saying a bit is more severe than another. While this is the case in the literal sense, a soft bit can be more severe and unkind to a horse when used by a rider with heavy hands, compared to a rider with kind hands using a severe bit.There are other types of horse bits not listed here,including more specialised ones orbits intended for behaviouralcorrection or very sensitive mouths.One such type is the Chifney bit, which is used to lead a horse from the ground, including horses that are prone to rearing, or those who need more control, such as stallions.A Chifney bit should never be ridden in.Regardless of their purpose, bits come into contact with a highly sensitive part of the horses body.Even the gentlest bits can cause pain and discomfort when the person on the other end of the reins is using them heavy-handedly. This is the key message that every horse owner and rider should know and keep in mind when choosing which bit will best suit you and your horse.Which horse bit is best for what?Because bits work in different ways, you canhelp or hinder any issues you have bychoosing a bit type accordingly.Of course,you should rule out any discomfort beingcaused by another part of your tack or in thehorses body before assuming the bit is theproblem. Horse bits manufacturerSprenger advises the following:Horses with a sensitive mouthA single-jointed bit means riders can givesofter aids via the reins and are particularlysuitable for horses that do not take thecontact confidently.Horses who occasionally pullA double-jointed snaffle is ideal for horsesthat occasionally pull against the hand,but are too sensitive to be ridden in astronger bit.Horses who lean or evade the bitA straight and rigid Mullen Mouth can beused for horses that dodge downwards andlean on the bit, or evade the rein and tendto get strong.Horses who get strongA straight and flexible Mullen Mouth can suithorses who become strong or unresponsivewhen working on the flat, or approaching ajump. These bits are usually accepted well byhorses who dislike double-jointed bits.Horses who have a big tongueA Mullen Mouth with port allows more space for a fleshy tongue to sit underneath it. It can also correct issues such as horses putting their tongue out to the side of their mouth when worked, or getting the tongue over the bit. This bit type is also particularly suitable for horses who resist their riders hand.How to fit a horses bitMouth conformation can have a direct effect on the bits action and how it fits in the horses mouth.Be mindful that the horses mouth hasnt evolved to have room for the bit. There is no natural space between the tongue and roof of the mouth, so it is up to us to make sure the bit is as comfortable as it can be for the horse, says Angela Rudrum from Equine Bitting Solutions.Some horses may have unusually large tongues, while others have small, thin lips. Some may have a narrow mouth and thin, delicate bars.A horses breed can sometimes determine their mouth conformation, continues Angela. Some breeds have typically thicker lips and tongues, such as the Irish Draught, which can leave little room for thicker bits, while some finer breeds like Thoroughbreds will have smaller tongues and less lip thickness and thinner bars.How to assess a horses mouth1 Lip length and shapeLook at the shape and length of the horses lips, explains Angela. Some have what is called a short smile; this is where the lips are short from the corner of the muzzle to the corner of the lip. A short smile can be challenging when you are adjusting the bit position in the mouth.Avoid raising the bit to an excessive height, as this can cause the horses lips to be uncomfortable and become too stretched, potentially causing them to split.2 Lip thicknessHave a feel of the horses lips from the outside.Its easy to tell if a horse has fleshy lips as you can squeeze a handful and they can be quite prominent when looking at the horses head from the front, says Angela.Thicker lips take up more room inside the mouth and so leave less room for thicker bits. When the bit is in position, thicker lips may appear to have more wrinkles than thinner lips.3 Inside the mouthDo this when the horse is relaxed and not eating.From the side, gently separate the lips top lip upwards and bottom lip downwards so you can see the resting tongue, bars and tushes.Be careful not to pull the lips back towards the cheek teeth and to keep your fingers clear of these teeth, advises Angela.Horses have incredibly powerful jaw strength, around 500psi, which can easily crush a finger if its mistaken for food.4 The tongueNotice how the tongue sits in the mouth.A large, thick tongue may bulge out the sides and be the most prominent part of the mouth. It will appear thick and completely fill the mouth. A thinner bit would be beneficial for the horse so that it does not take up too much room and they can still easily swallow, says Angela.A thinner, narrow tongue sits neatly behind the incisors and doesnt bulge beyond the bars. Horses with a narrow upper and lower jaw can also have a narrow tongue, which means some bits with a wide lozenge or French link plate will be uncomfortable, adds Angela.5 Bars of the mouthThese are the spaces between the teeth and where the bit sits.The bars are the mouth are very sensitive as they are not covered with much cushioning and have only thin skin covering them, explains Angela.Horses with large tongues and flesh lips will be able to support a bit, helping to keep it clear of the sensitive bars. However, horses with a thinner tongue and lips may show evasions to a bit that touches the bars. In this case, the horse may prefer a thicker bit to spread the pressure over a larger area.6 Roof of the mouthThe palate is a very important part of the horses mouth to consider when choosing a bit.Some horses have whats called a low palate, which means the roof of the mouth sits fairly flat, without an arch. If the palate has a rounder, arched shape it can be called a high palate, says Angela.The palate has visible ridges and it is soft and sensitive. If a bit affects the roof of the mouth, it can encourage the horse to open their mouth or raise their head.Some bits can cause injury to the roof of the mouth if they are too thick or make a steeple shape when the rein aids are applied, especially if they horse has a low palate.Designers of horse bitsSprenger horse bitsThese bits are made from Aurigan, an alloy of copper, silicon, and zinc which has been developed specifically for using in horses mouths.The manufacturers claim that using Aurigan helps your horse become more attentive and relaxed, improving the connection between horse and rider. The range was developed with horse mouth conformation in mind.Research found the volume of the inside of the mouth was less than previously thought, leaving much less room for the bit. Sprenger used this information to develop their KK range of bits.Find out moreInformed Designs, by Hilary VernonThis range of bits is made up of English bits designed and carefully constructed to complement the conformation of the horses mouth to improve comfort and communication.Informed Designs is inspired by the theory that a comfortable horse will be a more relaxed horse and therefore a less resistant horse. The range includes snaffles, pelhams, doubles, daleheads, Liverpools and butterflies, with a variety of cheeks on these mouthpieces available.View the rangeAbbey EnglandThese horse bits are made in the UK and there aremore than 200 different bit patterns in stock.The range includes snaffles, gags, pelhams, double bridles, driving bits, and hackamores.These horse bits are available in various materials including copper, stainless steel, sweet iron, rubber and vulcanite. They aremade-to-measure bits which can easily be customised from existing parts for comfort and quality.See the rangeNathe horse bitsThese horse bits are made in Germany from a patented plastic material, and claim to offer a higher degree of comfort and control.The secret of their effectiveness and flexibility is said to be a unique mouthpiece, protected by a worldwide patent.Each bit has a stainless steel safety wire running through the mouthpiece for total security.They encourage salivation and are kind to the tongue, so are ideal for training young horses.Try the rangeNeue Schule horse bitsMost Neue Schule bits are made from Salox. This range of dressage and competition bits are all designed with the shape of the horses mouth in mind.The use of Tranz lozenge for comfort and communication gives even pressure over the tongue and away from the outer edges where the horse is more sensitive.Learn moreMyler horse bitsDesigned by the Myler brothers, this range of horse bits claims to create a kinder, more of effective way of communication with your horse.The bits have a forward-curve shape to give the horse more tongue room to allow for swallowing. Myler bits have a no-pinch action and each side moves independently to make rider aids clearer.Some of the horse bits in this range come with slots in the cheeks. The top slots work in a similar way to a full cheek bit with keepers holding the mouthpiece off the tongue and steady until the rider uses the reins.The bit returns to its original position once the rein aid is relaxed making the reward much clearer to your horse.Using the slots also gives some poll pressure, encouraging a horse to flex from the withers.The range of Myler horse bits is split into three levels depending on your horses level of training. Level one is designed for young horses at the beginning of their training; level two is for horses with a basic training; level three is designed for more experienced horses.See the rangeAll images: copyright Shutterstock, Sprenger, Your Horse Library/Kelsey Media/Mel BealeRelated contentBridles tried and tested for fit, performance and value for moneyWould your horse benefit from going bitless?Riding a strong horse? Why changing to a stronger bit might not be the solutionBridle fit and horse head anatomy: everything you need to know *VIDEO*How to keep horse teeth healthy and problem freeThe post Handy A-Z guide to horse bits plus fitting advice appeared first on Your Horse.