Description of the Grandvallier harness.

Our harnesses are made from Biothane®, which makes them easy to maintain—simply use soap and water. All hardware is made of stainless steel.

The only measurements needed are these:

The complete harness must consist of the following parts:

  • the breeching
  • the breeching martingale
  • the back strap / girth
  • the traces

The setback.


Above is the upper bar with its back straps that connect the breeching to the collar, and the two rump bars with their trace rings. The two additional dees are used, for example, to attach a manure bag.

The breastplate has two rings for attaching the breeching straps and two additional rings for a manure bag.

Detail of how the trace is fastened to the trace carrier when the horse is not hitched to the carriage.

The Standing Martingale


The breeching martingale is the key component of American-style breeching. It is attached to the collar and is used to support the shaft and connect the breeching (via the breeching straps) to the shaft.

Here you can see the two breeching straps fastened to the ring of the lower martingale strap, and the girth passing through the loop provided for this purpose.

Martingale Adjustment

The martingale is correctly adjusted if:

  • The shaft is low enough so that the lower strap of the martingale does not rub against the horse’s chest.
  • The shaft yoke must be in front of the projection line of the shafts.

Guide Spreaders.


When driving in pairs, rein spacers allow for more precise action on the bit.

The dotted lines in the drawing below represent the reins passing through the spacers.

The spreaders can be attached to the upper ring of the splints.

Above, the guides are “Italian-style”.

When pulling in a flexible manner (agricultural work or logging), the shaft spreaders can be placed on the croup.