Link for inverted tooth chain with optimized shape for increased strength

A chain and sprocket drive system comprising:

• a sprocket;
• and
• an inverted tooth chain assembly configured to mesh with the sprocket, the inverted tooth chain assembly including at least two rows of links,
• each of the links having two teeth, a pair of outer flanks, first and second inner flanks, a crotch located between the first and second inner flanks, a first transition point arranged between the first inner flank and a first end region of the crotch, and a second transition point arranged between the second inner flank and a second end region of the crotch, wherein a crotch surface defined between the first transition point and the second transition point has a profile with a varying radius of curvature, the profile of the crotch surface has a smaller radius of curvature at the first and second end regions and a larger radius of curvature at a medial region between the first and second end regions.