Timepiece barrel with improved transmission of force

A timepiece barrel, including at least one mainspring cooperating at the inner end thereof with a core pivoting about a pivot axis, and at the outer end thereof with an inner track of a barrel drum by means of a resilient sliding bridle, wherein said inner track and said resilient sliding bridle are each of non-circular shape, and nest one inside the other in the free state of said resilient sliding bridle, and are arranged such that at least one outwardly radially projecting raised portion comprised in said resilient sliding bridle is abuttingly engaged with at least one inwardly radially projecting sill comprised in said inner track when the torque applied to said resilient sliding bridle is less than a torque limit value, and wherein at least one said raised portion of said resilient sliding bridle is subjected to a radial constriction when the torque applied to said resilient sliding bridle is greater than said torque limit value, to allow said raised portion to pass over said sill and to allow said bridle to travel angularly under the effect of said torque until the next encounter between one said sill and one said raised portion, wherein said resilient sliding bridle forms a closed contour and includes a plurality of said raised portions.