Zero Dirt bike

When the Zero X wheeled onto the dirt track at Lake Elsinore, the Colgate-white motocross bike looked positively virginal next to the belching, candy-colored models that leaped from mound to mound around it.

Not surprisingly, the Zero X drew a lot of attention.

Two-stroke? Four-stroke? That wasn't the question riders were asking after watching the electric dirt bike roll around the track a few times and do everything a traditional, gas-powered motocrosser could do, minus the noise and pollution. No. The biggest questions were: "What is it?" and "Where can I get one?"

The Zero X is a big deal for a lot of reasons, the biggest being that it's actually in production. Unlike so many other electric vehicles that are bandied about in the media, it isn't a prototype. It's been on the market since April.

Nor is it an electric retrofit of a gutted, formerly gas-powered machine. Its 300-plus component parts were engineered from the ground up, sourced from manufacturers around the globe and assembled into fully functioning motorcycles in a facility in Northern California.

The $7, 450 motorcycle was designed by aeronautical engineer Neal Saiki, whose mountain bikes have won design awards.

Saiki came up with the idea for his electric motorcycle in 2003, after participating in a NASA think tank project analyzing transportation solutions for the U.S.

"It was really obvious that electric was the right choice for the United States. It makes so much more sense than hydrogen and other technologies, " he said. "The military's had extremely high-powered electric vehicles for quite a long time, and it was just a matter of time before they came down to the [private] sector."

He set to work on the X, then incorporated Zero Motorcycles Inc. in 2006. To get the company off the ground, Saiki and his wife sold both of their homes and brought in investors such as Gene Banman, a former top manager at computer maker Sun Microsystems Inc. and now Zero's chief executive.

The company, based in the Santa Cruz area, has 31 employees, has shipped 40 bikes since April and has back orders for an additional 60.

Among his customers is Google Inc. founder Larry Page, who bought three Zero X bikes.

Zero is setting up a second production line to meet demand. Saiki anticipates selling 500 motorcycles next year, both for the dirt and the street. He figures to be doing $100 million in business by 2011.

"I don't expect a lot of competition, " the 41-year-old Saiki said. "It takes a lot of sophistication to get a manufacturing operation started."

The motocross category is, in many ways, the perfect application for an electric power plant because motocross bikes are ridden for only a few dozen miles at a time and battery-powered motors are typically limited in their range.

The whisper-quiet operation in the hills also won't offend nearby residents.

Electric motors are pure torque machines, which is what a motocross bike needs to launch into jumps and power out of corners. The Zero X can get to its top speed of 57 mph in about four seconds.

One potential downside to an electric application in a dirt bike is the weight of the batteries, a problem Saiki chose to tackle with a feather-light, aircraft-grade aluminum frame and lithium ion batteries.

Those batteries have a greater power-to-weight ratio than the nickel metal hydride devices used in the Toyota Prius and the Vectrix scooter.