A Plug-in Motorcycle

Brammo's Enertia puts bikers on the grid

3 min read

As one of us--the heavier one--approached the first major hill on a test ride of Brammo Motorsports' new Enertia electric motorcycle, we were doubtful that this light, elegantly designed bike could haul a 109-kilogram (240-pound) rider up the incline. We shouldn't have worried: it effortlessly propelled him to the top of Portland, Ore.'s West Hills.

Thanks to the central positioning of the batteries and motor, the Enertia handled the winding roads with ease, and its wide rear tire kept the wheels on the ground even when accelerating through turns. It rode and handled predictably and comfortably. The suspension was somewhat stiffer than that of most gasoline-fueled bikes, yet it took bumps, potholes, and railroad tracks in downtown Portland without trouble.

One thing was missing--the roar of the engine. The ride was surprisingly peaceful without it. We attracted curious glances from pedestrians, drivers, and bicyclists, who expected a growling hog but instead saw a stealthy tiger.

To stretch battery life, the bike is preset to draw only 150 amperes, or 60 percent of the maximum power. That gives it more than enough spunk to navigate busy traffic. The motor develops 20 kilowatts (roughly 26 horsepower), but according to Brian Wismann, the Enertia's design director, what really matters for an electric vehicle is torque--of which the Enertia's motor produces 46 newton meters (34 foot-pounds). By comparison, a 250-cubic-centimeter gas-fueled motorcycle typically provides about 28 Nm (20 ft-lbf). That means the Enertia takes off, accelerates, and rides just like a gas-fueled motorcycle.

Craig Bramscher, a veteran of several small Web-related companies, founded Brammo in 2002 to pursue his interest in specialty vehicles. In 2005, he secured a license to build the Ariel Atom, a British sports car notable for having almost no body panels--just its naked exoskeletal chassis. Soon he began looking to build an electric vehicle, but the need to minimize weight brought a change in plans. He elected to build a motorcycle--including the motor, drive train, suspension, and carbon-fiber body--from the ground up. Today most electric motorcycles are mere conversions of gas models.

Given the bike's range of 75 kilometers on a charge and a top speed of 80 km/h, Brammo is positioning the Enertia as a commuter vehicle for what it calls the new urban consumer--25 to 44 years old, interested in green products, living within 40 km of an urban center, and crucially, not necessarily a current motorcycle rider.

Those people will have to fork over US $15 000 for one of the first preproduction Enertias. (A comparable gasoline-fueled 250-cc sports motorcycle can be had for $4000 to $5500.) The price is likely to drop as production ramps up, and as a green machine, it will qualify for tax rebates in some states.

Anyway, what you save in gas may finally offset the extra initial cost. A 250-cc bike can go about 300 km on a tank of gas, which in the United States costs $7 or more, but the Enertia can go as far on four charges, totaling just $1.30. That cuts the energy cost by three-quarters. (Of course, it won't be so convenient, because each charge takes about 3 hours.)

The power source is an array of six lithium-phosphate cells from Valence Technologies, of Austin, Texas, which also supplies the battery-management system to balance the current draw from each of the batteries. Bramscher says Valence's system is the best he's seen--and supersafe to boot. ”You can cut these batteries in half with a chainsaw, and they will not ignite,” he says.

The designers and engineers kept the bike simple and unintimidating for novice riders. There is no clutch; the only controls are the throttle and the hand and foot brakes.

Instead of a gas cap, there's a lid that conceals the charging port, which works off 110-volt household current. Closer to the rider is the power button, and mounted above the handlebar is a small flat-panel display showing speed, the remaining charge, and how much carbon you avoided pumping into the atmosphere by taking the Enertia instead of a car.

Brammo is taking orders for delivery by the second quarter of 2008. By then the bike will also have a port that will allow owners to use their laptops to reprogram the performance characteristics of their Enertias, download ride telemetry, and more.

”We're going to let you download to the bike, change the throttle map, and alter the power settings,” Wismann says. ”Some hardcore motorcyclists want every bit of power available to them. We're going to give them the chance to fiddle with it.” More power to the motor, of course, will come at the expense of range.

In the second half of 2008, Brammo will introduce a production version of its first model, priced at $12 000. A second model will follow, carrying both a rider and a passenger. With greater battery density and a more muscular motor, it should have a top speed of about 120 km/h, fast enough--and powerful enough--for highway driving. Sure, the Enertia is green and efficient. But it's also a fun ride.

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