CT16 is used both in the front and rear of the 800r/800rr series. they will wear over time and it is advisable to change these as needed. some slop in the CVD is good for low grip conditions as it will create more grip, but slop is not advisable in high grip tracks as the car will not be as free, leading to excessing drive train bind and in turn unwanted grip which is especially noticeable through corners.