The secret of Trak’s high automation and incredibly quick fitting is to be found in the supporting universal joint, consisting of chain tensioning arms. These arms rotate around their axis without any friction and their position allows them to apply a high flexible force on the guides, resulting from a better combination of shape and flexibility of the material. The combined action of the force applied across the rubber, generated by the arms and by the centrifugal force applied to the moving tyre, automatically moves the chain to the most suitable position.