Quantifying Engine Braking for Various Common Street Motorcycles 2020-01-0880

Motorcycle engine braking will be measured in each forward gear for a cross-section of typical street motorcycles. Using GPS data acquisition and video, curves will be developed showing deceleration relative to engine speed, ground speed, distance, and time. Motorcycle characteristics will include low, middle, and high displacement sport, V-twin two-cylinder cruiser, single-cylinder adventure, three-cylinder, and shaft-driven. Motorcycles will be accelerated to approximately 70 mph when achievable in the respective gear, and throttle will be abruptly closed. The motorcycles will cruise unbraked until 15 to 30 kilometers per hour. For control, each motorcycle will be accelerated to the test speed and shifted to neutral to measure combined wind and rolling resistance. Tests will be performed on level ground and in opposing compass directions to account for wind. The data acquired will give more insight to what extent engine braking is a factor for accident reconstruction. Further, it will show the variability between frictional losses for different types of motorcycle powertrains and drivetrains.