They say: “Modern and unique, yet reassuringly familiar.”
We say: “Gears and a clutch make a real electric motorcycle.”
The most common criticism of electric bikes is that they don’t feel like “real motorcycles.” The magic-carpet character of a silent, vibration-free motor with a tabletop-flat torque curve is novel and even exhilarating, but especially for experienced motorcyclists this can seem dull compared to a screaming, slightly unpredictable gas engine. There’s also the fact that every eBike built to date has been single-speed, eliminating the skill required for—and the autonomy that results from—shifting gears. It’s just not the same.
Electric vehicles don’t need transmissions. Because torque in an electric motor is a function of current and not rotational speed, there’s little need to manipulate engine rpm to build or control power. Max torque is essentially available from zero rpm, and power output is controlled digitally by the motor controller to make it tractable. Single-speed drivetrains also save the considerable cost and complexity of having to design, engineer, and manufacture a transmission.
That’s not to suggest, however, that an eBike wouldn’t benefit from a gearbox. A single ratio inherently compromises acceleration or top speed—you can’t optimize for both at the same time. There’s an efficiency cost, too. Then there’s the riding experience—shifting gears makes a bike more dynamic, more fun…more motorcycle. So when Brammo set to work designing the Empulse, its most ambitious electric motorcycle yet, adding a six-speed transmission was a priority. The Empulse would not only offer performance parity with an internal combustion engine (ICE) bike, it would deliver a similar riding experience, too.
A top speed over 100 mph and useful range approaching 100 miles puts the Brammo on parity with the latest Zero models and closes the gap to ICE bikes. The Empulse looks like a proper motorcycle, too, with an aggressive streetfighter design that accurately transmits the Empulse’s performance potential. “We didn’t want to style a superbike replica and then have the performance let buyers down,” says Brammo Director of Product Development, Brian Wismann. “We wanted it to look like what it is—an honest, fun, urban streetfighter.”
I rode the Empulse shortly after attending the Triumph Street Triple R press launch last November, and commented on how similar the two bikes felt. This wasn’t coincidental, Wismann explained—Brammo actually benchmarked the Street Triple prior to designing the Empulse, and the ergonomics and chassis geometry are very similar. The major differences are the Empulse’s slightly longer wheelbase to make room for all that battery, and a slightly lower, narrower handlebar.
I spent a half-day riding the Empulse around San Francisco, subjecting it to steep hills, repeated full-throttle launches in stop-and-go traffic, and some spirited sport riding around Twin Peaks—exactly the mixed-urban usage that Brammo intends for this bike. It was the perfect real-world test of the Empulse’s performance claims, and an excellent opportunity to see how adding a transmission enhances the eBike experience.
First things first: You don’t use the Empulse transmission like you would a conventional motorcycle’s. The clutch is needed only to shift gears—and shifting gears is completely optional. Because the electric motor delivers such a broad spread of torque, it’s possible to ride the Empulse smoothly, at least in an urban setting, in any gear. The only difference is the rate of acceleration. Establishing forward movement is still a twist-and-go affair—there’s no need to use the clutch coming to or leaving from a stop.
I find this problematic at first. I simply can’t break the habit of pulling in the clutch at every stop and then slipping it as I pull away, which only causes the engine to spin up without creating forward motion. Wismann is actually pleased to hear I had so much trouble: “That only tells me that we accomplished our goal of making it feel like a real motorcycle!”
Once I finally learn to ignore the lever and just twist the throttle, I’m fairly amazed at how hard the Empulse jumps off the line. Brammo claims 60 lb.-ft. of torque at the peak, but the term “peak” isn’t applicable here. The torque output is digitally restricted until 4500 rpm, when it enters what Brammo refers to as a “continuous power region” where the curve remains essentially flat, without peaking or falling, right to the 8200-rpm redline. This makes the Empulse feels like it accelerates significantly harder, and for significantly longer, than any ICE bike with a similar torque output. It might only have a 100-mph top speed, but it feels like it gets there as quickly as any superbike.
Utilizing the six-speed gearbox only enhances acceleration, despite slightly notchy shift action. And since peak motor efficiency occurs between 5000 and 6000 rpm, multiple gear ratios make it easier to keep the Empulse operating at maximum efficiency over a wider range of speeds, to help maximize range. The Empulse is rated at 438 MPGe (miles-per-gallon gasoline equivalent), which translates to a claimed range of 121 city/56 highway/77 combined. I rode just more than 40 aggressive miles in San Francisco’s challenging, mixed-urban environs and returned to Scuderia West with 40 percent of the battery charge remaining. Still worried about being left for dead? All Empulse buyers will receive a free two-year roadside assistance membership with Motorcycle Towing Services (MTS).
With aggressive geometry and high-end running gear from Marchesini, Marzocchi, Sachs, and Brembo, the Empulse is fun and easy to ride fast. Steering is neutral and predictable, and the suspension is firm and perfectly balanced despite the fork and shock being sourced from different firms. Things only got twisted in the most technical corners, where you were reminded the Empulse weighs a stout 470 pounds (claimed). The weight distribution feels biased toward the front, as it takes some effort to initiate tight turns and it can occasionally be hard to stop the bike from turning without adding a bit of throttle.
Overall, the Empulse R is a remarkably fun bike that finally combines the futuristic, TIE-fighter appeal of electric propulsion with the dynamic excitement and interaction of a traditional ICE bike. And the future is now: The first customer Empulse was delivered December of last year, and at press time the company was building 10 bikes per day in its existing Ashland, OR, facility; a new, 100,000 square-foot production facility opening in mid-2013 in nearby Talent, OR, is expected to allow the firm to deliver 2000 bikes this year, Wismann says.