(CNN) -- From city suburbs to crowded urban centers, small-wheeled folding bicycles are finding a new credibility. Once dismissed as novelty toys or stash-in-the-trunk conveniences, they now are being seen as a way to get everyone on a bike.
Yet when it comes to folders -- as they are known -- the difference between a $350 entry-level model and a $3,500 customized version goes far beyond the price tag.
"Cheap, unreliable and under-satisfying bikes, folding bikes and electric-assist bikes may get people into and out of bicycle commuting quickly," says Peter Reich, inventor and designer of the Swift Folder bicycle.
"[But] well-built bikes bought by informed, dedicated commuters (not trend-seekers or fitness-obsessors) will continue to build a good foundation for 'normalized' bike commuting."
Reich has built about 520 custom folding bikes to order in his solo shop in Brooklyn, New York, while the large-scale manufacturer Xootr has sold thousands of Swifts since their partnership began in 2005.
Michael McGettigan owns the Trophy bike shop in Philadelphia and estimates the market for folding bikes as "iPod-sized."
"iPods made music very easily portable," he explains. "The new wave of better folders like Xootrs, Bromptons and Bike Fridays make people portable.
"Folders are an intelligent response to the fact that the regular world puts a lot of barriers into the way of using a bike," McGettigan continues, "like 'you can't bring a bike in here, you can't do this, you can't do that...' A folder is only a bike when you need it. The rest of the time it's a parcel."
As for his own square-folding Brompton -- an esteemed British brand -- he covers it under a soft black shroud and then brings it into restaurants, checks it into museums and uses the handicapped stall when he's in the bathroom en route.
McGettigan owns nine bikes, but 50 percent of the time he uses one of his two folders.
David Lam is the passionate owner of bfold folding-bicycle shop in New York.
For the past seven years he has observed three major types of customers for folding bikes: casual but curious cyclists attracted to the unique design; serious but frustrated cyclists who rarely get to take their expensive road bike out of the garage; and, most unfortunately, people who just had their bike stolen.
Currently only 1 percent of New York City commuters are cyclists, according to Transportation Alternatives' Director of Bicycle Advocacy Caroline Samponaro, who claims this percentage represents that of most big cities in the U.S.
However, the Big Apple has seen a 28 percent increase in the number of cyclists since 2008 to reach a current total of 201,000 daily riders.
This growth in cyclists in New York is tied to the creation of 322 kilometers of bike lanes in the past three years, says Samponaro, making the famously walkable metropolis also the most bikeable in the U.S.
New York City buses are now required to accommodate folding bikes, while another law requires all commercial buildings to either allow bicycles to enter the building or to provide a secure and sheltered alternative. The "Bikes in Buildings" law was passed in December 2009, following requests from some 300 tenants, and in response to the number one reason given by people for not cycling to work: no place to park their bike.
According to Brompton's Ross Hawkins, there are a number of big challenges to mainstreaming the folding bikes.
"[They are] disproving many of the myths and stigma surrounding small wheels; showing individuals that sharing a road with other vehicles is not as dangerous as perceived; showing that through good clothing choice, cycling does not always leave you drenched in rain or sweat," he told CNN.
Today, following a manufacturing boom in the 1980s, more than a hundred brands of folding bicycles worldwide compete for a growing market of small-wheeled cyclists.
But if the mass-marketed Dahon claims 60 percent of the U.S. folding-bike market, according to research by The Folding Cyclist, there is plenty of space in the market for other higher-end folding-bike manufacturers.
Quality folders come from German-designed Birdy, award-winning Strida and tiny-wheeled CarryMe. Brompton has earned an international cult status with quality British craftsmanship and a perfected one-size-fits-all design in a range of customizable colors.
From the other side of the Atlantic, Bike Friday is earning a reputation in making custom-fit folding bikes.
So how do folders fit into the world?
In fast-developing countries such as China, bicycles are seen as the lowest common denominator of urban mobility. In lower-density regions such as North America and Australia, biking is a primarily recreational activity. Northern Europe remains the traditional stronghold of urban cycling. Taiwan and Japan cultivate a growing proportion of folding bikes.
Many see small-wheeled bicycles as upping the ante for both style and convenience. When the bicycle becomes a practical prosthesis, anyone can morph from a public transit commuter to a folding cyclist to an empowered pedestrian. Then again, you don't even have to be a commuter to love riding a finely crafted, fully engineered bicycle with fashionably small wheels.