Thieves are eyeing bicycles as big business, leading to a recent spike in thefts of pricey bikes concentrated in a particular grouping of Manhattan neighborhoods.

And while bike thefts have been consistently increasing over the past decade, grand larcenies are going up at a significantly higher rate, indicating that thieves are targeting high-priced rides, experts said.

Bucking the city's overall crime trend, these grand larcenies are highly saturated in neighborhoods like the West Village, East Village and the Flatiron District, according to NYPD statistics obtained through a Freedom of Information Law request.

"This kind of crime is one we refer to as victim precipitated," said Joseph Giacalone, a retired NYPD detective who lectures at John Jay College of Criminal Justice. "Like anything else, if you leave out the opportunity for someone to commit the crime they're going to do it. People get sloppy with their own stuff. They say this is the safest city in the world and they start to believe you."

So far this year, there have been 559 grand larcenies of bikes as of Oct. 26, an increase of about 64% from the same period last year, according to police statistics.

These grand larcenies have a typical minimum value of $1,000.

More than 30% of these types of grand larcenies are centered in four precincts, which include neighborhoods like the West Village, NoHo and Stuyvesant Town, according to the most recently available precinct breakdowns from the NYPD as of Aug. 31.

In the 10th Precinct, which includes Chelsea and the High Line, there were 31 grand larcenies of bikes in the first eight months of this year, a 210% increase from the same period last year.

This increase has defied the citywide trend for all grand larcenies in Police Commissioner Bill Bratton's first year. Grand larcenies in general have decreased by 3.2% as of Oct. 26 when comparing 2013 with this year, according to NYPD statistics.

And bike thefts in total are on the rise. Citywide, there were 4,134 bikes stolen as of Oct. 26, an increase of about 10.5% from the same time period last year, according to the police statistics. And bike thefts have been consistently going up, increasing by more than 183% from 2003 to 2013.

While there may not be one simple reason for the increase, experts point to a coalescing number of factors common in these neighborhoods: a more tourist-centric population, the ease with which thieves can blend in, the noise factor to mask their efforts, and the increasingly high demand for these bikes.

The NYPD did not respond to requests for comment on this story.

Biking has become increasingly popular in New York over the past several years as the city has pushed for more access.

The city's Department of Transportation installed more than 213 miles of bike lanes between 2009 and 2013. More than 48 additional miles are planned this year, a DOT spokesman said.

"Bikes are good money. Everybody wants one," said Hal Ruzal, a mechanic at Bicycle Habitat in SoHo and a longtime bike expert. "It's very easy to come around those neighborhoods with a van, make a lot of noise -- there's a lot of people -- and steal a lot of bikes.

"People are coming here from towns where bikes don't get stolen," Ruzal added. "They buy an expensive bike and they get stolen. Thieves know what to look for."

In fact, many people feel so safe in the city that they don't even lock up their bikes, Giacalone said. Arielle Milkman, 24, was visiting a friend in the West Village in 2011 when she left her pink bike unlocked behind the building. She was upstairs for a few hours working on classwork while a thief made off with her primary mode of transportation, she said.

"It wasn't a very smart thing to do anyway because it's New York," Milkman said. "I sort of kicked myself for not being hyper vigilant."

Milkman, who was living in Bushwick at the time and now lives in Washington, D.C., searched in vain for a used bike on Craigslist for a few weeks before resigning herself to buying a new bike.

She did not report the theft to police, believing they couldn't do much about it. Instead, she bought a lock. "I am much more vigilant every time I have things stolen in the city," Milkman said.

Bike thefts often go unreported to the police, making the issue harder to combat, said Caroline Samponaro, deputy director of Transportation Alternatives, an advocacy group for bicycles, walking and public transportation.

"People don't always report that their bike was stolen because they don't always feel comfortable that anything can be done about it," Samponaro said. "Knowing how to solve the problem means knowing the extent of the problem."

More secure bike parking is a great first step, she said.

"There's lots of solutions," Samponaro added. "I think we just need more of it."