If you've ever been riding down the street and had your pants cuff ripped asunder, there may be a revolution at hand.

Trek Bicycle is part of a movement to bury the finger-pinching, pants-munching, rust-prone sprocket and chain, and usher in an era of belt-driven bikes that might have the inventors of the self-propelled transportation Schwinning in their graves.

Wisconsin-based Trek is introducing two models this holiday season that are chainless, instead using technology most often found in things like motorcycles and snowmobiles. While some smaller custom bike makers have used them before, Trek is the first to use the technology for mass-produced bicycles.

The nation's largest domestic bike manufacturer is hoping to capitalize on a new group of urban pedal-pushers who are trading their cars for a more low-tech way to get around because of gas prices as well as health and environmental concerns.

The U.S. bicycle industry was a $5.4 billion industry in 2007, including the retail value of bicycles, related parts, and accessories through all channels of distribution, according to research funded by the National Sporting Goods Association. More than 43 million Americans age 7 and older were estimated to have ridden a bike six times or more in 2005, the industry group said.

“People are really finding bicycles to be a very simple solution to some very complex problems that they face every day,” said Eric Bjorling, Trek's lifestyle brand manager. “Anything we can do in our design to really help them and help them live that lifestyle is probably better for both the consumers and us.”

Bjorling said the new belts are a low-maintenance solution to a chain, which has roughly 3,000 parts including all the links and connectors.

Aside from the whisper-quiet ride, the lighter and longer-lasting carbon-fiber composite belts won't rust, can't be cut, won't stretch or slip and won't leave grease marks around your ankles. A guard over the belt-drive and the construction of the system makes getting your pants stuck an unlikely scenario, Bjorling said.

One version of the chainless bike, called the District ($930), is a single-speed, complete with a silver body, orange accents and brown leather seat and handles. The other, called the Soho ($990), is an eight-speed bike that uses an internal hub to adjust the speed rather than gears.

Bicycles have come along way from the “boneshakers back in the 19th century,” said Orin Starn, a professor at Duke University who teaches a course on the anthropology of sports. Some companies have used direct drive or drive shaft bikes that provide some of the same benefits as Trek's chainless bikes, but those models have yet to replace the age-old chain.

“Certainly for the last 40 or 50 years we have this iconic image of the traditional bicycle that includes the chain,” Starn said. “We've seen this evolution in different styles and stuff, but the chain has been a cultural constant.”

Bjorling admits chain-driven bikes are still efficient, but said an urban rider won't have to worry about greasing or cleaning the chain. The belt can be cleaned with a normal cleaning agent and rag, and the bike sprocket is designed to push through any snow, dirt or grime. And one belt will typically last three years - the life span of three chains.

How riders will take to the new bikes remains to be seen, since they are not out for sale yet. The District model will go on sale in December, followed the next month by the Soho. There may be those in the biking community that may take issue with swapping bike chains with newer technology.

“Bike purists are going to take a look at it and say Ôoh, you know it's another option to a chain,'” Bjorling said. “Are we going to see a ton of people switching from a chain to a belt drive? I think in some urban environments yes, but it's definitely not the coffin that's gonna bury the chain.”

Over the years there have been many changes in the bike industry, specifically materials that have made products lighter and stronger, said David Oakley, a manager at Agee's Bicycles, which has been in business in Richmond since 1910.

While some may question the chainless bikes, Oakley pointed to the initial skepticism, and eventual success, of mountain bikes.

“We all know that putting gears on a beach cruiser to be able to ride back up the hill turned out to be a pretty good thing,” Oakley joked of the bike industry's most popular segment.

Oakley said there's a general excitement behind the new technology, but cautioned that the notion may not ring everyone's bell.