Power transmission chain and power transmission system

A power transmission chain, comprising:

• a plurality of links each including front and rear inserting portions;
• and
• a plurality of first pins inserted into the front and rear inserting portions and a plurality of second pins inserted into the front and rear inserting portions, the first pins and the second pins being aligned for connecting together the links that are aligned in a chain width direction so that the front inserting portion of a first one of the links corresponds to the rear inserting portion of a second one of the links,
• wherein the links are configured to bend relative to each other in a length direction by relative rolling contact motions of the first and second pins,
• wherein the links include two types of links, a link L1 having a small pitch length and a link L2 having a larger pitch length than the pitch length of the link L1, and the first pins include two types of pins, a pin P1 having a rolling contact surface with a large radius of curvature and a pin P2 having a rolling contact surface with a smaller radius of curvature than the radius of curvature of the pin P1, and
• wherein, with respect to either only the front inserting portions of the links or only the rear inserting portions of the links, the links and the pins are arranged so that only the second one of the links having one of a combination of the link L1 and the pin P2, and a combination of the link L1 and the pin P1 comes immediately after the first one of the links having a combination of the link L1 and the pin P2 in a chain traveling direction.