As part of its Transforming Mobility initiative Yamaha Motor Co Japan has developed a motorcycle electric power steering system (EPS). This rider aid, currently in prototype testing stage, is aimed at improving motorcycle stability and agility.

Differing from systems in use in automobiles and other four-wheeled vehicles, the Yamaha EPS uses a magnetostrictive torque sensor. This allows the system to function as a steering damper at high speeds while simultaneously acting as assisted steering at low speeds.

For the rider, benefits are increased stability and improved agility while reducing rider fatigue, thereby raising the fun, safety and comfort factor. The actuator in the EPS converts electric signals into physical movement using a torque sensor giving it two distinct functions.

When functioning as a steering damper, EPS counteracts outside forces sent to the handlebars from changes in the road surface, reducing unwanted handlebar movement at high speed. The assisted steering feature comes into play at low speeds, complementing handlebar inputs in line with the rider’s intentions.

The system is designed to provide active intervention in the motorcycle steering while still feeling natural for the rider. EPOS is being tested the Yamaha YZ450FMs and YZ250F racing motorcycles competing in the All Japan Motocross Championship as part of its real world testing, with data gathered used to develop EPS that will eventually be installed in production motorcycles.