Many motorcycles are now fitted with disc brakes; these have advantages of simplicity and fade resistance but can be dangerously inconsistent when wet. Using a simple braking distance measurement technique a number of possible solutions to this problem have been examined, including the use of various disc and pad materials and treatments to them. None was found to be effective apart from the use of sintered metal pads which gave substantially consistent results, wet or dry. A wet brake test which would eliminate unsatisfactory installations has been proposed as part of the European type approval system and some suggested test methods and parameters have been examined; the importance of the choice of realistic levels of braking and brake watering rates in identifying unsatisfactory materials is highlighted. (Author/publisher)
Abstract