Riding a bike can be fun, great exercise, and, if you live in a city conducive to it, a great mode of transportation.
According to author Scott Bennett who lives in Vancouver BC, Canada, a city with a high bike theft rate, he “wanted to have some peace of mind that if a thief with an angle grinder were to cut through my U-lock I could still catch them.” He’s had a lock cut before (only his girlfriend’s bike was stolen, his was left behind!), and is determined not to let his new bike disappear.
To this end, he decided to design a system where if the bike is stolen, it will send a GPS signal back to him, helping to catch the culprit. This is cleverly accomplished by using the wire as a conductor; when cut it triggers the Arduino processor to start sending out distress text messages via a GSM shield. The assembly is stored in a small bag below the seat which a thief would hopefully assume contained only, say, a spare inner tube.
One disadvantage of this design is that you have to buy a phone plan, but there are prepaid options available that won’t cost you an arm, leg, or bike to maintain. It’s a small price to pay to secure a bicycle that could easily cost into the thousands of dollars.
One last note: Seriously people, use your angle grinders only for good, not for bike thievery!