Bicycle manufacturers Giant, Raleigh and Trek are expected in the coming weeks to roll out three-speed bikes that feature chip-controlled, gear shift systems.

The technology, called "Coasting," was built by Shimano, a bike-component maker for 80 years.
The system works the same way on each of the bikes. A dynamo is fitted on the front hub that gauges the revolutions of the wheel. It sends this information to a computer chip housed near the pedals on most of the bikes.
From there, the chip, which controls the planetary gears located on the back hub, determines whether to shift up or down. All the chip needs to make its determination is for a rider to pedal four or five times, according to Shannon Bryant, Coasting project coordinator for Shimano.
Coasting isn't designed for high performance, such as road racing or mountain biking. (See related story on the Coasting technology).
"It's not intended for even inclement weather," Bryant said. "This technology is for casual use or social riding...somebody who wants to tool around town."
The biking industry is mired in a slump. The sector happily rode a wave of popularity in the 1980s and '90s when mountain biking and road racing were the rage, but sales in recent years have been flat, said Bryant. Like a lot of companies targeting outdoor sports, Shimano is trying to tap new technologies in an effort to win back the 161 million Americans who haven't ridden a bicycle since they were children.
Recent surveys conducted by Shimano, headquartered in Japan, found that many Americans equate biking with road racing, Armstrong, unflattering cycling shorts and sticky sweat.
Asked whether Armstrong, the retired road-racing professional and seven-time Tour de France champion, inspired them to get on a bike, Americans said "no," according to Bryant.
"Bicycling got kind of elitist," Bryant said. "Our surveys showed people didn't necessarily want fitness or competition. They told us they loved riding as kids and would ride as adults if they could do it again in a carefree way."
Bryant said that Shimano has plans to continue developing the Coasting technology.
Another perk that Coasting provides is that the dynamo powers not only the computer chip but can also run the headlamp so owners won't ever need batteries.
The bikes debuting on Thursday will sell for between $450 and $700, Bryant said.