The difference between a cob bridle or a full, or horse- size bridle is simply that cob sizes are smaller. These bridles are used in the English disciplines, so these terms aren't necessarily used for Western bridles. Just because your horse generally wears a cob or full-size bridle doesn't mean you can just order a new one online or pick one off the rack at the tack shop. Different manufacturers use various sizing, so you must measure your horse and measure the bridle.
Cob is a British term, not used as much in the United States. It isn't a specific breed, but a type. Equines requiring cob-sized bridles are usually large ponies or small horse, ranging in size from 14 to 15 hands, with 14.2 hands the dividing line between pony and horse.
Certain breeds, such as the Morgan or the the actual Welsh Cob, Section D, will generally wear cob bridles. A cob-sized bridle might also suit a small thoroughbred or other breed that usually wears a horse-sized bridle, depending on the size of the animal's head. A cob type with a smaller head might need a pony-sized bridle.
Measuring the Head
If you're simply replacing your old, well-fitting bridle, bring it with you to the tack store for a size comparison. If you're dealing with a new horse, measure his head with a fabric tape.
- Figure the appropriate length of the crownpiece by measuring from the edge of your horse's mouth, over his poll, to the same point on the other side.
- Measure the throatlatch from the back of one ear, under the throat, to the back of the opposite ear.
- Measure for his noseband by placing the tape 1 inch beneath his cheekbones and measuring his circumference of his muzzle at that point.
- Measure the browband from the back of his ear to his forehead and around to the opposite ear.
The Nunn Finer Co. lists several different bridles in cob and horse sizes. Two bridles list the same size for crown and cheek pieces for cobs -- 12 inches and 9 inches, respectively. The equivalent horse sizes are 13 inches and 10 inches. However, one bridle states that the cob size cavesson, or noseband, is 23 inches at the nose and 27 inches at the poll, while the other cavesson is 27 inches at nose and 33 inches at the poll. That's nearly identical to the horse size for the brand, which has the same nose size but is 34 inches at the poll.
Ask the sales representative at your tack store which brands run small or large. Even if your horse generally fits fine into standard horse-size bridles, a cob size of a particular brand may fill the bill. Cob bridles are often a bit less expensive because they are smaller.