Tongue relief bit – ports, mouth space and correct fit

Short answer: tongue relief is created by a curve, port or centre-piece design. It can free part of the tongue’s centre or move contact to other areas. Less central contact does not automatically mean less total pressure.

A low, broad curve acts differently from a narrow, high port. Width, angle, thickness, flexibility and position must be assessed together. When contact reduces centrally, it may increase at the sides of the tongue or on the bars.

Tongue space may be built into a mullen mouth or created by the shape of a double-jointed mouthpiece. The word anatomical alone does not guarantee a particular distribution.

It may interest horses with a full or sensitive tongue, but does not automatically solve an open mouth, tongue over the bit or inconsistent contact. Check teeth, size, bridle, training and hands as well.

Low port or high port?

A low, broad curve may create space without approaching the palate as closely as a narrow, high port. Height alone does not determine comfort. The port’s width, angle and position, the mouthpiece thickness and the available palate clearance all matter.

How to check fit

Confirm that the curve faces the intended direction, remains centred over the tongue and leaves appropriate clearance. The cheeks should not pinch, and the horse must be able to close the mouth comfortably. When trialling tongue relief, keep other variables as stable as possible.

Frequently asked questions

Does tongue relief remove all tongue pressure?

No. It changes space and contact distribution; it does not necessarily remove all contact with the tongue.

Is a higher port better for a thick tongue?

Not automatically. It must also fit beneath the palate and work with the rest of the mouthpiece.

Bit sizes in millimetres and inches

Common ByLynga size labels for Ireland are 95 mm (3¾ in), 105 mm (4¼ in), 115 mm (4½ in), 125 mm (5 in), 135 mm (5¼ in) and 145 mm (5¾ in). Measure the mouthpiece itself and check the individual product’s available sizes; inch values are practical rounded equivalents.

Compare mullen mouth bits and double-jointed snaffles, or return to the mouthpiece comparison. Browse all horse bits.

Competition rules

Permitted bits depend on the discipline, class, age category and the complete design. Before competing, check the current Horse Sport Ireland rulebook, the relevant affiliate’s rules and, for international competition, the FEI Rules & Regulations. Links checked 9 September 2026.