LINCOLN PARK — On a sunny Wednesday morning as moms, kids and workers walked along Halsted Street, a bike thief worked in plain sight.

It was as easy as lifting a tow zone sign right out of its base, slipping the U-lock off the metal pole and riding off with the lock still attached to the frame of the bike.

Couldn't have been more than 10 seconds.

"He had the pole in his hand when I saw him, and he had it up in the air," said Kathy McInerney, a 24-year-old Lincoln Park resident. "He threw it back down into the [base], and he just hopped right on [the bike and went] down Lill."

McInerney called the cops and gave them a description of the hooded thief, but he was long gone.

A "sucker pole" sits near Halsted and Lill streets in Lincoln Park, where a thief recently made off with a bike that had been locked to it. View Full Caption DNAinfo/Paul Biasco

The bike was attached to a "sucker pole," according to Howard Kaplan, founder of the Chicago Stolen Bike Registry.

Thieves will remove the bolts that secure street sign poles to their bases, allowing them to easily lift the poles out of the base later. Unsuspecting riders don't notice the missing bolts, and lock their bikes to the poles, falsely thinking they'll be secure.

The theft, like many in Chicago, was likely an easy one for the thief, Kaplan said, but even if the pole had been properly screwed into the base, those bikes also are an easy get.

"There's so many instances of people pulling poles out of the ground or unbolting them," said Kaplan, a 50-year-old Little Village resident. "It almost doesn't matter if the poles are bolted down anymore."

Some thieves are using power tools to quickly unscrew the lone bolt holding down the poles to make off with bikes whose owners often have nowhere else to lock them.

In the last year, the Chicago Stolen Bike Registry has recorded 90 thefts in instances where the bicycle was locked to a street sign. Another 180 bikes were swiped from metal poles, pipes and fences, according to the website's statistics.

From Nov. 1, 2011, to Nov. 1, 2012, 94 bikes that were locked to street signs were stolen, and 158 that were locked to a pole, pipe or fence were stolen. From 2010 to 2011, there were 82 bikes stolen from street signs and 125 from poles, signs or fences.

Those numbers are all Kaplan and his team can go by, as the Chicago Police Department does not keep specific data on bike thefts.

Kaplan estimated that only about 10 percent of the city's stolen bike victims take the time to log onto stolenbike.org and report the thefts, let alone know about the site.

"If we get seven reports on a day, there's probably 70 or 80 or 90 citywide," he said.

At Bike Lane Chicago on Milwaukee in Logan Square, the mechanics have begun to notice a pattern of thieves in the neighborhood.

A crew of high school-age kids travel their usual routes keeping an eye out for certain "sucker poles," according to Bike Lanes' staff.

"These kids know where these poles are," said Joe Wisniewski, a mechanic at the shop. "They ride their route, see a bike there, and it's quick."

The packs of four or five kids ride the streets, not only looking for complete bikes, but also high-end parts — Brooks saddles in particular — which go for around $150, according to Wisniewski.

There is even an online marketplace for the crews to get rid of the stolen goods quick, Facebook.

The group "Chicago Bike Sellers" has nearly 3,000 members, and in a 24-hour period this month, there were more than 120 posts from sellers.

One user advertised handle bars for sale in two listings with the description "offer up" and "any offer," while others included a full, fixed-gear bike with the description "Need this gone ASAP."

There are single wheels, pedals, frames and even bike lights going for dirt cheap compared to retail prices or even prices on Craigslist.

Late Thursday morning, one Facebook user posted a listing of a Brooks saddle for $25 "delivery ASAP."

A few posters pointed out that the saddle was "obviously stolen," and the seller replied "every brooks on this page is basically stolen, so who gives a f**k."

"What pisses me off the most is the arrogance of it all," said Adam Glenn, co-owner of Bike Lane Chicago. The sellers "are so stupid about it, and no one is doing anything about it."

Glenn realized how quickly those bikes sell firsthand.

His girlfriend's Logan Square apartment was broken into this summer, and a week later a co-worker sent her a photo of the $1,000 bike for sale on the Facebook group.

Glenn was out of town at the time, and police said the only way to take action would be to set up a sting. By the time he got back in town, the bike had been sold.

The police are aware of the group, Glenn said, but are unable to obtain arrest warrants off Facebook posts.

"I think the police think, 'Oh it's a $200 bike, I'm not gonna waste my time on there,'" he said.

The neighborhood even has a famous "sucker pole" of its own in front of Go Tavern, 3219 W Armitage Ave., according to the Bike Lane guys.

Two years ago the group behind the stolen bike registry filed a Freedom of Information Act request with the city to see if there was an official number of stolen bikes for the previous year.

The answer they received was vague, somewhere between 5,000 and 7,000, according to Kevin Conway, an administrator for the registry.

Over the last two or three years, Kaplan and his website have seen a jump in the number of bike thefts citywide.

The site saw a 40 percent rise in reported stolen bikes from 2011 to 2012.

"It's a pretty big one-year jump," Conway said. "I don’t know if that’s more people riding bikes, more people having bikes stolen, or more of an awareness on peoples' part of Chicago’s stolen bike registry."

One major reason for a perceived rise in thefts is the lack of places to park a bike, leaving many cyclists with no option other than the dreaded pole.

Before the city's infamous parking meter deal replaced nearly all 36,000 meters — along with their securely fastened poles — bike rack deserts did not exist.

"People used to be able to use parking meters, and from one day to next, they are all gone," Kaplan said.

There are 14,500 bicycle racks in Chicago, along with 13 on-street bike corrals, according to city data, and more are scheduled to be rolled out. Groups such as the Lincoln Park Chamber of Commerce have shelled out cash to install racks in their neighborhood.

The question of whether to lock to a pole or not, even for a quick stop, recently was a subject of hot debate on the Chicagocentric online bike community, The Chainlink.

"Pretty much anything you read anywhere about where and how to lock your bike, they discourage locking your bike to a sign," said Kevin Conway.

McInerney, who witnessed the theft Wednesday, said the dangers of locking a bike to a pole had never crossed her mind.

"He was quick. He did everything so quick, it looked like he knew exactly what he was doing," she said.

Even after seeing the theft, McInerney said she doesn't know what's she's going to do when she bikes in certain areas of the neighborhood.

"There's hardly any racks," she said. "Where else do you lock them?"

While the number of stolen bikes has increased in recent years, according to the stolen bike registry data, Kaplan said police have begun to show a greater concern.

"I think they are just realizing it's getting out of control and are wanting to do something about it," he said.

The staff at Bike Lane are doing their part by running serial numbers on anything that looks suspicious through both The Stolen Bike Registry and bikeindex.org.

Most of the time it's obvious, Glenn said.

A high schooler wearing sneakers will roll in a $1,500 bike with pedals that require special shoes to clip into and ask the mechanics to take the pedals off because he doesn't know what they are.

Other times, a bike will be three times too big for whomever brings it in.

"I had a guy come in with a $5,000 bike, and I couldn't do anything about it because it wasn't in the registry," Wisniewski said.

While Wisniewski was unsuccessful in recovering that stolen bike, just this year, Glenn has recovered four or five stolen bikes that people have brought into the store for either a tuneup or to have parts swapped out.

He said once a stolen serial number or description of the bike shows up in the registry, the staff will confront the customer with a choice of waiting for the police or getting out.

Nine out of 10 times they leave.

The Bike Lane staff recommends cyclists make distinguishing marks on their parts, such as branding a saddle, to make recovery of stolen goods an easier process.

One thing that everyone can agree on is it's worth the extra block or two or three to find a proper rack.