Yamaha Unveils AWD and Electric Power Steering for Concept E-Bikes

‘All-wheel drive’ for motorcycles is not a new idea – but motorcycle expert Yamaha now looks to extend the concept to the bicycle world.

The Y-01W AWD is Yamaha’s concept bicycle promoting 2-wheel drive. (Yamaha)

If driving all four wheels of an automobile has advantages, it seems sensible that driving both wheels of a motorcycle or bicycle also would offer certain performance and/or stability enhancements. Two-wheel drive for motorcycles has been attempted numerous times by many manufacturers — albeit with few genuine production-run examples — but it took the comparatively recent advent of electric assist to make the 2WD concept possible for pedal bicycles, or e-bikes.

Hub motor drives the Y-01W AWD’s front wheel. (Yamaha)

Yamaha revealed in mid-October leading up to the 2023 Tokyo Mobility Show a 2WD concept bicycle called the Y-O1W AWD. It is targeted at the expanding “gravel bike” segment, featuring models more offroad-capable than a conventional road bicycle but less dirt- and trail-ready than a full-blown mountain bike. For electric mountain bikes (eMTBs), the company also intends to reveal a prototype electric power-steering (EPS) system.

Hub motor for front drive

Yamaha, which in 20004 marketed one of history’s handful of production 2-wheel-drive motorcycle models with its WR450F 2-Trac, offered on its website previewing its products for the 2023 Tokyo Mobility Show  a few scant details for the Y-O1W AWD concept bicycle. “This adventure eBike combines a center-mounted electric motor and a hub motor at the front for two-wheel drive,” the company said. “Coordinated electronic control of the two motors, twin batteries enabling long-distance rides, wide tires and more give the Y-01W AWD excellent off-road performance and it is a concept model that points to the many potential spheres of riding open to eBikes,” Yamaha continued.

There is no indication regarding whether Yamaha intends to bring the Y-01W AWD to production, but the company does have an established lineup of ebikes, including those in the gravel-bike segment as well as the electric mountain-bike (e-MTB) market, where 2WD presumably might provide a significant boost to performance and reduction of rider fatigue.

The Y-00Z MTB concept’s small electric power-steering motor housed on the bike’s steering head. (Yamaha)
The “split drive” layout for the Y-00Z MTB’s driveline. (Yamaha)

To now, e-bikes have been the most prominent application for hub motors, which also are proposed for 4-wheeled vehicles given the design and propulsion-arrangement flexibility they present. The preponderance of current e-bikes use hub motors, but at the rear wheel only. The use of bicycle rear-wheel hub-motor layouts has been preferred for its comparative simplicity and adaptability to existing bicycle models, as well as for cost advantages.

Yamaha’s short-lived 2-wheel-drive WR450F 2-Trac used an Ohlins-developed hydraulic drive to power the front wheel, highlighting the primary challenge of nearly all 2-wheel-drive motorcycles prior to the electrification revolution: how to connect the power from an internal-combustion engine to a front wheel suspended away from the engine itself and that must remain free to steer and accommodate radical suspension movement.

Philadelphia, Pennsylvania-based Christini Technologies currently offers AWD motorcycles and conversions. Rochester, New Hampshire’s Rokon, which made its first 2WD motorcycle in 1958 also currently makes 2-wheel drive motorcycles and claims to be “the world’s original and longest producing manufacturer of all wheel drive motorcycles.”

EPS – for bicycles?

Although a mountain-bike might seem a more natural fit for all-wheel drive, Yamaha instead chose its Y-00Z MTB mountain-bike concept to showcase a prototype electric power-steering system. (Yamaha)

In addition to the 2WD Y-01W AWD, Yamaha also said it will display at the Tokyo Mobility Show its Y-00Z MTB, a somewhat conventionally styled eMTB fitted with an electric power-steering system. The Y-00Z MTB is equipped with a center-mounted or “mid-drive” motor but not a front hub motor.

Yamaha said the EPS borrows from technology developed for its existing e-bikes. “Based on a “Yamaha Motor Off-Road DNA” concept, this is a technical showcase of what is possible with eMTB technologies,” Yamaha said. “It combines a split arrangement for the drive unit with an Electric Power Steering (EPS) system employing a magnetostrictive torque sensor proven on our PAS line of electrically power-assisted bicycles,” the company continued, adding, “The result is both excellent handling and stability in off-road riding.”

The “split arrangement for the drive unit” refers to a small drive sprocket from the motor positioned above the pedal sprocket rather than integral with it. The company did not elaborate on what advantage this layout may provide.