BMW Electric Motorcycle

[Hugh Janus]

BMW is working on an electric motorcycle with a motor that appears to be from the CE-04. (BMW/)

BMW has been at the forefront of the electric two-wheeler movement for years—the C-Evolution scooter debuted more than a decade ago—but despite several concepts and running prototypes we’ve yet to see the company adopt battery power for a full-on motorcycle rather than a scooter.

Now that looks like it could change, with patent applications emerging that show a small electric bike that appears to be built using a combination of existing components including powertrain elements from BMW’s latest electric scooter, the CE-04. They’re repositioned and neatly packaged into a bike the size of the G 310 roadster, with an innovative arrangement for the motor. It’s positioned at around a 45-degree angle, with the motor’s shaft running longitudinally rather than the more common transverse arrangement. That means the motor can be relatively large but remains narrow enough to fit between the rider’s legs.

BMW’s patent shows a unique angle for the motor’s placement in the chassis and with the shaft running longitudinally. (BMW/)

The battery is also at an angle, running parallel to the motor and just ahead of it, roughly where you might expect the cylinder bank of a conventional, transverse internal combustion engine would sit. The frame isn’t shown in BMW’s patents, but since the G 310–series bikes actually have an unusual reverse-cylinder engine—tilted backward rather than forward—the electric model seen here won’t be able to carry over the stock G 310 chassis.

Most of the components, including the battery pack itself, the motor, and the electronics, mounted in two units—one attached to the motor, the other slung underneath it—all look very much like they’re from the CE-04, but shuffled to fit a completely different type of bike. On the CE-04, the battery is mounted horizontally in the floor, with the motor transversely mounted behind it and the control electronics stacked under the rider’s seat. That makes for a long, low arrangement that’s ideal for a scooter but unsuited to a more conventional motorcycle. Here, by moving the parts around and tilting them at an angle, the wheelbase can be far shorter and the center of gravity raised, a recipe for significantly sharper handling.

If, as it appears, the battery and motor are from the CE-04, then the performance would also be in line with that model. That means a peak power of 42 hp and 46 lb.-ft. of torque. On the scooter, the top speed is electronically limited to 75 mph, but that might not apply to a larger-wheeled bike like the one seen here, and range is rated at around 80 miles between charges.

The biggest difference introduced by the new layout is the motor position and orientation. Turned from transverse to longitudinal mounting, the motor drives through a new reduction gearbox with a bevel gear to take drive to the front sprocket. A belt final drive then transfers the power to the rear wheel, reducing maintenance and noise compared to a chain drive.

BMW’s new layout still retains some valuable storage space, too, as the fuel tank area is left clear to be used as a trunk—clearly big enough to store a helmet, if the patent drawings are representative of the bike’s real proportions. Like the G-series single-cylinder bikes, there’s also scope to make several different models based on the same components. The patent sketches show a larger-diameter front wheel than rear, suggesting a “GS” style adventure model, while using the headlight and seat from the “R” roadster. A full-faired bike, similar to the G 310 RR, might actually make even more sense, with aerodynamic advantages to squeeze the most range possible from the battery.

Source

[Buckster]