As a cop on a bike, she quit doughnuts, lost 12 pounds, built muscle tone, made hundreds of arrests. Her response time has never been faster.
Late Thursday afternoon, a man tried to shake down a parking lot attendant near 10th and Arch, in Chinatown. The attendant, Darrin Gardiner, distracted the would-be robber, reached for his mace and scared the man away. He called the police, and within three minutes Sperber - with her partner, Ray Felder - had pedaled to the scene.
"Pretty quick," said Gardiner, who bikes to work himself.
Sperber was not impressed with herself. She makes an arrest, she's happy. This one got away.
Often they don't. Sperber estimated that as a biking police officer she has
assisted on or made more than 300 arrests. Many of her pinches are of people selling fake drugs and fake jewelry.
"Lot of flimflam in Center City," said Sperber, a 30-year-old South Philadelphia native who now lives in the Northeast.
She bikes with a .38-caliber Smith & Wesson revolver attached to her waist by a nylon holster, obscured by her windbreaker. "Sometimes the bad guys don't even know we're cops until we're on top of them," she said.
There are 10 biking police officers; seven work throughout Center City and three work South Street specifically. They owe their existence, said William Schmid, a lieutenant in the Center City district, to the CoreStates Pro Cycling Championship, which showed police administrators how fast and effective a bicycle is for transportation.
The bikes, worth about $500 each, were donated to the Police Department by Bike Line, a chain of cycling stores.
"The cop on a bike legitimizes other bikers," Schmid said. For years, he explained, many motorists showed little regard for bicyclists. Now that there are bicyclists in a position to hand out citations and make arrests, bicyclists in general are being taken more seriously.
Sperber will put between 12 and 25 miles on her bike per shift, she said, much of it down alleys that can't accommodate cars and shouldn't accommodate officers working foot beats.
"I've dodged a lot of rats going down alleys," Sperber said. "A cop would be stupid to walk through them."
Some of the things Sperber did as a kid, while biking around the Stella Maris Parish with her friends on $50 bikes from Kmart, she now does for a living: "You know, jumping curbs, power slides."
A power slide occurs when a bicyclist going full speed hits the brakes hard. The bike screeches to a halt and the back tire slides out 90 degrees so that the bike stops perpendicular to its original direction. This move, Sperber said, is very useful when chasing a running law-breaker.
The crook is running from sirens. He doesn't see the innocent-looking bicyclist coming at him. The cop gets within a few yards of the bad guy, goes into a power slide and trips the guy up. Instant barricade.
Cop: Police! Freeze! You're under arrest!
Bad guy: All right, all right, but could you get the bike off me? Chain's getting grease all over my coat.
"Works great," Sperber said.
Two of the biking officers are serious bikers in their non-work life: Dan Dutch and Joe McCabe ride in bicycle marathons, and recently went from Philadelphia to Atlantic City and back to Philadelphia in a day, 126 miles.
Now that she has built up so much leg strength and stamina, Sperber finds that she enjoys biking on her days off, and she often goes to Fairmount Park or Pennypack Park or up to New Hope.
"My job gave me a hobby and it gave me a sport," she said. "When I go on vacation I take a bike with me. Statistically, cops are supposed to die at 57. I'm hoping to beat that."