As a high-school football player, Craig Bramscher’s teammates called him “Brammo.” The nickname followed him as he built a personal fortune in the dot-com 1990s. Bramscher eventually became enamored with EVs and in 2002 launched Brammo Inc., an Oregon-based manufacturer of the Enertia battery-electric motorcycle.
There is a growing list of emergent electric-motorcycle makers, many bringing impressive design and engineering solutions. Besides Brammo, the roster includes California-based Zero Motorcycles, and Portland, Oregon's Moto Czysz, whose latest electric bike won the zero-emissions motorcycle race at the 2010 Isle of Man TT. A number of established makers, including KTM and Honda, have shown concepts. All face the same hurdles (cost, battery range, charging time, and mass acceptance) as car and truck EV producers.
Like the automakers, the electric-bike OEMs offer a strong clean-and-green appeal. And in the case of bikes designed for off-road riding and racing, the electric models are noiseless—a major plus at a time when off-road riding areas are being closed in some areas due to engine noise.
The foundation of the Enertia’s vehicle architecture is a twin-spar extruded aluminum main frame. Fitted compactly within the frame loop are the powertrain—a brushless, permanent-magnet AC electric machine rated at 17 peak hp (12.6 kW) and 44 lb•ft (60 N•m), a Valence 3.1 kW•h lithium-iron-phosphate battery pack, and the on-board charging module.
The Enertia’s chassis components are off-the-shelf items sourced from respected suppliers and tuned specifically for the application. Suspension is from Marzocchi (inverted-type forks) and Elka (rear monoshock). The brakes are by Brembo, their rotors mounted on cast-aluminum wheels designed in-house by Brammo. The bike’s molded-plastic body panels contain high recycled PET content, Bramscher said.
The Enertia weighs 329 lb (150 kg); most of its mass is located low in the machine—the e-motor is located at the bottom of the frame spars, at the swinging-arm pivot. The motor drives the rear wheel by conventional roller chain, which may produce (along with the Avon tires) the bike’s only operational noise.
While AEI has yet to sample the Enertia, motorcycle-media road testers report performance that would be acceptable in urban use or limited local commuting. Independent testing has shown the bike’s range on a single charge is approximately 30 miles, about 10 miles less than Brammo’s max-range claim.
An LCD display mounted on the upper fork crown alerts the rider when it’s time to start looking for a 110-V charging outlet.
Minimum state of charge is calibrated at 20%, with the control software providing a bit of slow-riding reserve power. Recharging time from minimum SOC is three to four hours, at 110 V. The Enertia’s 2010 retail price is $7995, which like automotive EVs can be lowered via various state tax incentives and a U.S. federal tax credit.