Curb chains or straps have no effect on a true snaffle because there is no leverage to act upon. English riders do not add any type of curb strap or curb chain to a snaffle bit. While some riders in western disciplines do add a curb strap to the rings, it is merely a "hobble" for the rings, has no leverage effect and is there only as a safety feature to prevent the rings from being pulled through the mouth of the horse, should the animal gape open its mouth in an attempt to avoid the bit, an outcome prevented in an English bridle by the presence of a cavesson noseband.