Originally Posted by gmacrider
The other day a co-worker's bike was stolen from a rack in front of our building in broad daylight. She showed me her U-Lock, it had been twisted like a pretzel until it broke (I guess they didn't know a bic pen would be a lot easier).
How could theives do this in broad daylight on a busy downtown sidewalk? What kind of tool would they use that could twist up a U-lock like that?
On a Wal-Mart quality U-lock, the "pretzel" technique can work in just five seconds. That technique will work in under two minutes on some "premium" priced U-locks. The speed and effectiveness of leverage attacks is why a crook is never going to waste an hour down on his hands and knees going through a box of pens, looking for the "correct" size pen that MIGHT work on one of a zillion models of U-locks made over the past three decades.
The "pretzel" technique will NOT work when a compact OnGuard U-lock is attached around the rear wheel of the bike (just behind the seat tube) and around a sturdy steel post. Not enough room to insert effective tools and generate the leverage needed.
And, the pretzel technique will not work against the Kryptonite New York lock. If the NYL is attached to the seat tube, a leverage attack will mangle the seat tube, but leave the NYL in "like new" condition. Another reason you should NEVER attach a sturdy U-lock around the frame itself. After a "leverage" attack, your bike will still attached to the rack, but you will need a new frame.