EK Chain 525 ZVX3 Series ZX-Ring Chain - 120 Links - Purple 525ZVX3-120APTheZVX3 series easily surpasses every other brand with a tensile strength of 11,100lbs. Adopted new ZX ring and last 15% longer than ZVX series Improved stiffness and weight (4. 85 100lbs.) For up to 1300cc Tensile Strength of 9400lbs. for 520 Chains Tensile Strength of 10,300lbs. for 525 Chains Tensile Strength of 11,100lbs. for 530 Chains