Europe, with a more robust cycling culture, is somewhat higher with 1.2 million bikes sold in a year. But those numbers are expected to rise, with 150,000 annual sales expected in the US and more than 2 million in the EU by 2014 as more people turn to cycling as car commutes become increasingly troublesome.

"For most of these people, taking a car to work is no longer an option," says Ludwig Meier, marketing director for Messe Friedrichshafen, co-organizer of the Eurobike Show, the world's largest bike tradeshow.

"Fuel costs aside, heavy traffic and a lack of parking spaces in downtown areas make the last leg of a car commute the most difficult. So, many people are parking outside of the city and using e-bikes for the last part of their journey," he says.

Meier, who visited China for the second annual Asiabike 2012 expo in Nanjing in late July, says consumers find e-bikes a better option than traditional bicycles because of the little exertion required.

"It would probably not look good for a banker or businessman to show up to work covered in sweat," he says.

With fuel prices in the US and Europe climbing steadily upward, it also saves money.

But it's not just commuters taking to the powered pedals. In addition to those looking for an environmentally friendly way to conduct day-to-day chores, the bikes have also hit a note with elderly riders, who use the power assistance to overcome steep hills and rough terrain.

"The people now buying e-bikes in Europe and the US fall into two classes - those who are focused only on the price of the bikes and those going after quality and style," Meier says.

Similar to electric scooters, which are growing in popularity, e-bikes in the US are limited to speeds of 15 miles per hour and in the EU to 25 kilometers an hour.

Though regulations vary from state to state and from country to country, the limited power and speed of the bikes allow them to be classified as non-motor vehicles, often requiring no license or registration.

China's early edge in the e-bike industry is due in large part to the government setting the sector's development as one of official technology goals in 1991. Chinese companies discovered new ways to create cheap, effective components, and the technology took off.

Between 1991 and 2001, annual sales in China went from 100,000 to a million, and have been climbing at a faster rate since. Cashing in on the demand, more than 2,500 Chinese companies were manufacturing e-bikes by 2006.

One of the oldest companies, Jonway Group, established in 1986, is among scores of companies now pursuing Western clients as it pushes to establish its brand early in the market.

Its main factory, housed among dozens of other e-vehicle manufacturing plants in the small coastal city of Taizhou in Zhejiang province, where a large portion of China's electric bikes and scooters are made, churns out hundreds of electric vehicles daily.

Of the 50,000 vehicles it will produce this year, 10 percent will be sold in Europe and the US, says Liang Yulin, sales manager at Jonway Group's electric vehicle division.

Europe takes up most of its overseas sales, he says, but as the US shows more interest, he expects exports to grow quickly due to the relatively easier export regulations there.