Mission Has Most Stolen Bikes in Bay Area

A recent analysis of Craigslist postings that describe lost bikes shows that the Mission district has the highest rate of bike theft in the Bay Area.

Engineer and self-proclaimed bike commuter and data geek Phillip Yip, 30, decided to analyze bike theft patterns after running into multiple stolen bike ads during his own search to buy a bicycle.

“I’m usually looking for bikes online, for myself or for friends, and I end up searching on Craigslist,” Yip said. He soon realized that many of the ads were not posted by people selling their bikes, but by those hoping to find their stolen bikes.

“People are pleading to get their bikes back,” he said.

The analysis uses information compiled over a span of three months, between July 2 and October 17 of this year. To collect, archive and organize his data, Yip used various features of Google, including Reader.

“I had Google archive a search for stolen bikes on Craigslist,” he said. He then searched for keywords in ads, including a search of the ad’s title, the location of the incident, and the time the ad was posted to the site.

After compiling the desired information, Yip played with different methods of graphing it. In the end, he used Adobe Illustrator to make it look “pretty.”

According to Yip’s research, out of 633 total bikes reported stolen, 224 posts were from San Francisco and 43 of those listed the Mission or Mission District as the location. Trailing close behind with a total of 46 reported bicycle thefts was Oakland, while Emeryville, also in the East Bay, had only one bike reported stolen.

The Castro, the Financial District and Civic Center were close behind the Mission, with 16, 15 and 12 stolen bike reports, respectively.

Yip’s data also shows that black is the color most frequently referred to in the data, with white, silver and blue trailing close behind.

Why take the time to compile all this information to begin with?

“Well, I’m a bike commuter, so that’s something that’s always on my mind,” said Yip. “And a lot of friends have had their bikes stolen or parts of their bikes stolen, so it’s always something that I think about and that I dislike.”

Yip has not had his bike stolen during the four years he’s lived in the East Bay. He says it might be because he has a “less attractive bike,” with some paint chipped off. But he also knows that nothing ensures a bike’s safety.

“I definitely know people that, you go out and you lock it up and you think it’s safe, and then you’re stranded.”

Next up on Yip’s to-do list? Figuring out how bikes are stolen, and what other things factor into the theft of a bicycle.

“I’m really interested in how it was actually stolen. That’s going to be a little harder,” he said. “I guess I’ll go through some descriptions of some of the postings and see if there are patterns that emerge, and go through listings that contain “lock” or “put” or “garage,” or something like that.”

His next infographic is due out in a few weeks. For now, Yip hopes his research can help prevent future bike thefts.

“I’m just hoping [to get] more information out there about how this sort of thing happens and how to have people avoid it happening in the future. And it’s fun to geek out on data.”