Motocross Monster. The 520MX boasts our highest rated tensile strength among non-sealed chains at 8,930 lbs. Perfect for the beating that chains take during tough, off-road races.Championship Quality. Trusted by the 2019 AMA SX Champion, Cooper Webb, and the Red Bull KTM Factory team, as well as 6X AMA ATV Pro MX Champion, Chad Wienen, the 520MX wins championships!Podium Performance. Utilizing our SDH pin treatment, with an extremely hard chromium carbide surface layer and a softer inner core, the 520MX is able to absorb shock loads without stretching and landing you on the box!