Motorcycle engineers continue to evolve two-wheeled technology with an ever-increasing smorgasbord of electronic rider aids to bolster safety and performance (cornering-ABS, traction control, adaptive cruise control, etc.). One of the latest electronic explorations comes from Yamaha.
The Japanese company is experimenting with an innovative electronic power steering system, currently in the prototype stage. Yamaha’s Electric Power Steering (EPS) is different from traditional power steering systems seen in automobiles and trucks.
The EPS uses a magnetostrictive torque sensor to measure rider input to the handlebar. It transmits that data to the system’s control board and determines the amount of assistance.
An actuator bolted directly to the motorcycle’s headstock translates the information and adds or reduces assistance (friction) through a geared shaft mated to the steering stem, applying appropriate force to aid steering depending on speed and rider input. The degree of influence the system initiates is directly dependent on how much physical force the rider is putting into the handlebar.
In addition to inputting alternating degrees of influence to ease turning at various speeds, the EPS sensors provide additional functionality as a steering damper at higher speeds. The system can differentiate between rider input and road influences, such as abject or uneven forces exerted against the wheels, and make adjustments accordingly.
All the while, the EPS retains a natural feel—and also reduces rider fatigue. It’s all part of the brave new world technology is bringing to motorcycles.
Easier and Safer Riding
The EPS is part of Yamaha’s Transforming Mobility Initiative, which stems from its research and development program aiming to address a variety of mobility-related societal issues. This reflects the company’s goal of generating broader appeal. The introduction of power steering to two-wheel machines potentially makes them more accessible to more people due to the increased ease of riding and added safety.
The new EPS system is currently being tested on the YZ450FM and YZ250F racing machines in the All Japan Motocross Championship, collecting data for application to other disciplines. Power steering as a viable option for motorcycles presents yet another rider aid that can add to safety and manageability—especially with larger, heavier motorcycles. Although motocross is serving as the system’s test bed, the advantages of electronic power steering on street motorcycles of all sizes and models is obvious, especially as it makes riding more enjoyable.
Power steering had a huge impact on the auto industry and is now the norm on virtually all cars, trucks, and four-wheeled vehicles. Similarly, the motorcycle industry and riders now embrace ABS, despite a great deal of negative skepticism in the years following its introduction.
It is perhaps only a matter of time before electric power steering becomes standard equipment on all new motorcycles, as well.