System weigth? Diameter rotors? Did you bleed the brakes? Possibly brake pads glazed. How did you use the rear brake?I bought the CANYON striven underdog with DB8 brakes as I wanted my bike black not green. The first 3 rides the brakes worked ok but not good as you have to push very hard in order to get an acceptable brake performance. Yesterday I was the first time in the alps in Grindelwald and I had a horrible experience during a long down ride.... 1st you get spasms in fingers and arms when you have to squeeze the brakes. After 2/3 of the down ride my back brake lost completely the pressure and I was lucky that on the right side was only gras as I turned right with 50 Km/h and jumped off the bike... nothing haamppend to me beside some minor blessings... the brake pressure was completely soft for 1/2 hour and came back partially again. It is a brandnew bike with brandnew brakes. This brake is dangerous and not constrcuted for Enduro or Downhill EMTB.... I will exchange my DB 8 brakes against Shimano, Magura or Acura... need first to study the latest test. SRAM DB 8 is dangerous and you risk ur life with it.