A double bridle, also called a full bridle or Weymouth bridle, is a bridle that has two bits and four reins (sometimes called "double reins"). One bit is the bradoon (or bridoon), is a modified snaffle bit that is smaller in diameter and has smaller bit rings than a traditional snaffle, and it is adjusted so that it sits above and behind the other bit, a curb bit. Another term for this combination of curb and snaffle bit is a "bit and bradoon," where the word "bit" in this particular context refers to the curb.
Double bridles are most commonly associated with dressage and certain horse show classes where formal tack, attire and turnout is standard. They are required for upper level FEI dressage tests (Prix St. Georges (PSG), Intermediare, and Grand Prix), and are optional at the USDF third and fourth level. They are also permitted in the dressage phase of eventing at the Intermediate or Advanced levels, although not required. (In eventing, even at the advanced level, snaffle bridles are still the norm.)
Double bridles are fairly common for horse show purposes in Australia, and in the United Kingdom for show hunters, but are less common at shows in the United States, except for Saddle seat, show hack, and upper level Dressage competition. Additionally, ladies riding side saddle traditionally use a double bridle. Double bridles used to be seen on show hunters in the United States, but that trend has waned with most now using a snaffle.
Double bridles are rarely used by show jumping riders and eventers in the stadium and cross-country phases. The double bridle is still sometimes used by cavalry and police horses.
While the snaffle bridle is more common, the double bridle, in the hands of an experienced rider, is able to transmit more nuanced commands and obtain more sophisticated responses from the horse. Thus, for advanced forms of riding, it is preferred.
