This paper describes a method for detecting the change in the conditions and behaviors of motorcycles from the motion data acquired by simplified measurement systems that estimate the dynamics of ride-type interfaces. In this method, motorcycle motion data, such as the acceleration and angular velocities, are determined using a microcontroller. Then, the changes in the conditions and behaviors of the vehicles, such as turning off the engine, beginning to run the engine, and braking, are detected by using the singular spectrum transformation of the motion data. Experimental results obtained with real motorcycles show the feasibility of the method.