Dynamic belt tensioner for Triumph Classic This new belt tensioner has been designed to maintain a light but constant pressure in the belt compensating the swingarm movement and absorbing and discharging each load on the spring, ensuring a considerable reduction in stress and lower load on the wheel and gearbox bearings as well as reducing the risk of a premature breaking of the belt. The belt tensioner does not require maintenance. Product for: Triumph Bonneville 2001-2015 Triumph Scrambler 2006-2016 Triumph Thruxton 2004-2015 Fast and easy to assemble. Ready for assembly and complete with instructions.