The Challenge SMSR stands tall amongst the crowd. Packed full of attention to detail, the Challenge SMSR delivers performance in the harshest of applications. Shaft mounted drives remove the need for couplings, mounting plinths and have virtually infinitely variable ratios due to the belt drive. They are also incredibly simple to fit. * Includes complete torque arm assembly * Fully interchangeable with other manufacturers * Production line manufacturing guarantees tolerances and consistent quality. * Gears produced on German manufactured hobbing centres to achieve the highest quality helical gear components. * Pinions; 8620 steel * Gears; 20MnCr5 steel * All gears are ground * Final heat treatment includes gas carburising to a depth of 1mm then grinding to DIN class 6. * Castings crack tested * All units test run for 30 minutes prior to final quality control checks. * Full traceability guaranteed with unique Challenge serial number. * Backstops also available. * Bushings coming soon.