RK's XRE series chains are the successor to XSO chains. Compared to XSO, XRE series chains feature a 20% longer wearlife. XRE chains include XW-sealing rings which provide two lubrication pools which help protect against high-speed abrasion and prevent dirt and debris from penetrating the inner rollers / bushings of the chain. XRE series chains are available in 520, 525 and 530 pitch. XRE's features create a perfect balance between high tensile strength and light weight while maximizing wearlife. Tensile strength: 8,200 pounds. Max cc racing: 800cc street and off-road. Max horsepower: 130 HP. Weight: 3.44 pounds per 100 links. Max chain width: 21.7 mm. Masterlink included: Rivet (Clip type sold separately).