Back to Basics - How to fit a bit

I have been asked to out together a few general guidelines for how to correctly fit and position a bit. Previously we spoke about how to measure your horse for a bit. Here we will discuss the fitting.

 Length of the bit

The length of the bit corresponds to the width of the horses mouth without being too wide or too narrow. This will cause trauma to the horses mouth, potentially causing more problems.  

The size of the bit should always be assessed at rest and when you take up a contact as the bit may come out of the mouth excessively when a contact is taken up. Equally it may squash if too small. 

Loose ring bits 

This category includes loose ring snaffles, gags such as the Neue Schule Universal or 3-ring gags, 4-ring dutch/bubble/pessoa gags. Also sliding cheek weymouths and any bits where the side of the bit, the cheek, can slide and move through the bore hole of the bit. 

With these bits you need to ensure your horses lips are free from the bit, generally we would expect to see 1/8" to 1/4" clearance from the lip to the ring. If the lips are anywhere near or over the hole, when the bit is put into action it may pinch the lips and rub. Jointed bits shorten in width when used creating a 'V' shape in the mouth, if the lips are over the ring then it will cause problems. Straight bar bits don't have this action and you may choose to just allow enough room the lips don't cover the hole. 

The easiest way to do this is by putting your little fingers curled around the bit between the lip and the rings to assess the gap. However it is very common for loose ring bits to be too big which will cause the bit to slide around in the mouth and saw from side to side with rein aids. 

Fixed cheek bits 

This category includes eggbutt, D-ring, full cheek and hanging cheek snaffles. Fixed pelhams, weymouths and any bit where the cheeks do not move. 

These are designed to fit more snugly to the sides of the mouth, but not so much the mouth and lips are squashed in. This allows for more stability in the mouth, which some horses prefer and prevents a sawing action when the bit is pulled from side to side. 

 Positioning in the mouth 

This is usually where people go wrong. Theres an old wife's tale that you should see 2 wrinkles in the corner of the mouth at rest. 

You should aim for 1/2 to 1 wrinkle at the side of the mouth but bear in mind all mouths are different and anatomy will play a huge role in where the bit sits correctly. Horses with fleshy lips will show more wrinkles than a horse with thin lips under the same tension on the cheek of your bridle. 

Some horses may have a 'shorter smile', this will show more wrinkling and it may be that you feel like moving the cheek piece down to release cheek tension. However, this may create rubbing on the corners of the lips and reduce the effectiveness of your rein aids. 


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