In San Francisco, where bike theft has gone up a reported 70% since 2006, a bike that can't be stolen seems like a pipe dream. Now three Chilean engineering students say they they've cracked the code, and have a working prototype of what they're calling "The World's First Unstealable Bike."

Designers Juan José Monsalve, Andrés Roi, and Cristóbal Cabello say on their Yerka Project website that their prototype bike "looks like a traditional bike to the naked eye, but it’s the safest bicycle you’ll find" because "we decided to make a lock out of the frame" so "the only way to steal it is to break the lock, which implies breaking the bike."

Having trouble getting your head around the concept? Then check out the video below, which illustrates a seductively simple locking process: in short, the bike's down tube opens to wrap around a bike rack or pole or whatever, then the seat is pulled off and inserted through the open halves of the tube to complete the "lock."

Is this the solution to everyone's bike theft woes? Will the SFPDBikeTheft twitter account fall into disuse? Treehugger's not so sure, saying "any lock can be picked and the bike stolen," and noting a comment elsewhere that said that "one good kick on that seatpost and it will be dented, making the bike unrideable for the owner." And then there's the issue of the wheels and saddle: CNET points out, this prototype leaves those vulnerable.

And there's also the fact that, so far, the bike is just a prototype, with, it appears, no roadmap for production. According to their site, "this project cannot be done without your help," which is typically where one sees the link to Kickstarter or the like, but the Yerka guys just ask you to take a quick bike theft survey and to give them your email address so they can "let you know as soon as they're available."

Hey, in a city where even folks who've found their stolen, registered bike reportedly can't get SFPD to help them retrieve it, surely there's someone who can help these guys fix their concept's flaws and bring it to market. Anyone?

[Yerka Project]