Bit fitted with cheeks and a curb chain which lies in the chin groove. Operates on the leverage principle acting on the lower jaw. In a double bridle, the curb bit is used in conjunction with a bridoon, or snaffle bit.

A curb bit is a type of bit used for riding horses that uses leverage. It includes the pelham bit and the Weymouth curb along with the traditional "curb bit" used mainly by Western riders.