What size bit should I choose?

Here are the steps to take when determining what size bit to choose:

1. Measure your horses mouth.  Idealy use a bit measuring tool for the best measurement, compressing the lips until snug and fit.  You can use a piece of twine or a soft stick but the measurement may be less accurate .  You are looking for the distance between the lips.

2. Consider the cheekpiece: If you are going to be using a loose ring, add 5mm to your measurement.  If you are using a fixed ring, dont add anything to the measurement.

3. Consider the mouthpiece:

  • If you are using a solid mouthpiece dont increase the size further. 
  • If you are using a semi-broken mouthpiece, add 5mm
  • If you have a mouth pice with a single break, double break or flexi material, add 10mm

For example: if you are using a loose ring bit with a double jointed mouthpiece, you would add 15mm to your initial measurement.


If you are changing bits and the mouth piece or cheek piece will be different to the one you are currently using, please use the chart above to determine what size you need.  You may need to go up or down by up to 15mm.

Examples of fixed cheekpieces:

  • Full Cheek
  • Baucher / Drop cheek
  • Eggbutt
  • Dee Ring
  • Pelham
  • Kimberly Dee
  • Elevator / Jumper
  • Kimblewick

Examples of loose ring cheek pieces:

  • 3 Ring
  • 2 1/2 ring / Universal
  • Williams
  • Bevel  / Wilkie
  • Tom Thumb
  • Loose Ring

Examples of fixed and loose cheek pieces:

  • Fulmer loose ring
  • Loose Ring Tube
  • Gold wings loose ring 

Examples of solid mouthpieces:

  • Bomber Blue
  • Happy Tongue

Examples of Semi-broken mouthpieces:

  • Ported Barrel
  • Ultra Comfy Lock Up
  • Elliptical Ultra Comfy Lock Ip
  • Ported Pivot
  • Barrel 20 / 30

Examples of 2-break mouthpieces:

  • McHardy
  • Elliptical
  • Control Plate
  • Tranz Angled Lozenge