Alfred Sempten , Roof Top Tent On Any Car submitted an answer on "STEPPED SHAFT SECTION DIAMETER 56*61 (KEYWAY 16*4*50) SPUR GEAR RADIAL3000,TANGENTIAL3000 + 1 SECTION WITH DIAMETER 60*65 (KEYWAY 18*4*50) HELICAL GEAR AXIAL7000RADIAL7400TANGENTIAL7800 JUSTIFY LOAD" Posted Tuesday, September 28, 2021 at 11:51 AM I have always been excited about an opportunity to spend a night camping in the forest, but the Backtrax roof top tent has completely changed my concept of the perfect adventure. I have always been excited about an opportunity to spend a night camping in the forest, but the Backtrax roof top tent has completely changed my concept of the perfect adventure.