High-Performance Yamaha Electric in Development

[Hugh Janus]

New patents show that Yamaha is working on an electric sportbike and trying to maximize how it utilizes space inside the frame, while also managing weight. (Yamaha/)

New designs revealed in Yamaha patent applications show that the company is working on ideas for a relatively high-performance electric motorcycle with a focus on maximizing the space for batteries and minimizing weight.

There have been plenty of false dawns when it comes to the idea of electric sportbikes from major ICE motorcycle manufacturers. There was a flurry of exciting electric concepts more than a decade ago, including Honda’s RC-E that was unveiled back in 2011, and Yamaha’s PES1 and PES2 from 2013 and 2015, respectively, but so far such machines have remained conspicuously absent from showrooms. That’s despite genuine intentions to accelerate electric-motorcycle plans. As far back as 2013, Yamaha’s official plan (published in its annual report at the end of that year) was to launch “EV sports motorcycles” inspired by the PES1 concept within two years. That document was later edited to change the two-year time frame to “in the near future” when it was clear the two-year schedule wasn’t viable, but it’s been more than a decade now and there’s still no electric sportbike in Yamaha’s range.

Related: Honda, KTM, Piaggio, and Yamaha Form Electric Battery Consortium

Yamaha showed its PES2 electric concept all the way back in 2013. <i>Yamaha</i>

Does that mean the idea has been dropped altogether? It appears not, as a new Yamaha patent application reveals that work is underway on an electric bike that’s clearly much more focused on performance than any of the company’s existing battery-powered models.

The patent shows a sportbike with a conventional-looking chassis combining a trellis-style front frame with a swingarm pivot that appears to be aluminum, but it wraps around a huge, finned case that contains batteries and electronics rather than a combustion engine. The design is clearly intended to maximize battery space, as the electric motor is mounted as far back as possible, driving the front sprocket via a reduction gearbox. The motor position means the rear suspension needs an unusually high shock unit to clear it.

This illustration shows a fully faired sportbike-style machine in the patent applications. (Yamaha/)

However, the focus of the patent is the battery case. While some high-performance electric motorcycles use liquid-cooled batteries, the Yamaha design opts for air-cooling in the pursuit of simplicity and reduced weight. Just as there are arguments for and against liquid- or air-cooling in combustion engines, the same applies to EV batteries. EV batteries are sensitive to temperature, operating best within a narrow range—often requiring heating when they’re cold or cooling when they’re hot to maximize their potential. Liquid-cooling helps keep them in that sweet spot, but at the expense of requiring arrays of radiators, pipework, pumps, and sensors. Air-cooling, meanwhile, has the benefit of reducing weight, cost, and complexity, and with future generations of batteries expected to be able to cope with a broader spread of temperature, it could make more sense—particularly on motorcycles where space and weight are at a premium.

The focus of the new patent is the battery case and batteries and how they are laid out. (Yamaha/)

Yamaha’s design simplifies the battery case, using a large central casting and tub-shaped upper and lower sections. It’s a design that’s intended to minimize the number of seams, reducing the opportunities for water ingress. Inside, there are four platforms, each carrying two battery modules. The sides and bottom of the battery case are finned for cooling, as are the undersides of each of the internal platforms. Those fins increase the surface area for cooling but also add more rigidity without increasing the weight.

Inside the top section, the bike’s control electronics and battery management system sit on top of the upper battery modules, while the inverter that changes the battery’s DC output to AC to feed the electric motor hangs underneath in the bike’s belly. The on-board charger sits under the seat.

How powerful would a bike like this be? That’s unknown, but Yamaha already has its own in-house EV powertrain business, supplying motors from 35kW (47 hp) to 350kW (470 hp) to external customers. With well over a decade of largely unseen development on electric bikes under its belt, it seems likely that Yamaha—like several of its rivals—is now simply waiting for the right market conditions to enter the arena for large, high-performance EVs.

Source

[YamaHead]

It'll be interesting to see how much this beast weighs....