Narrow wide profileprevents chain drops and need for chain tensioner fully compatible with rear clutch mechsfor ultimate in single ring performance throw the new rotor qx1 mtb q rings on your rex single speed cranks youll be using the same chain ring set up that led christoph sauser to victory at the cross country marathon world championships the qx1 has an increased ovality of 125 to help you accelerate better feel less muscle fatigue experience smoother torque and better grip off r