Locking your bike up to an immovable object is obviously the best way of keeping it from being stolen while parked, but what if you're just making a quick stop? Well, you really should still lock it to something, although Seattle-based inventor Mark Waldin thinks his Quick Stop Bike Lock may suffice when needed.
Installed on the steering tube beneath the handlebar stem, it disengages the bars from the front wheel when locked. This means that if anyone should try riding away on the bike, the handlebars will just flop uselessly from side to side, making the bicycle unrideable.
Additionally, if anyone tries picking up the bike and running off with it, an IMU (inertial measurement unit) within the Quick Stop will detect that they're doing so. The Bluetooth-equipped lock will subsequently alert the user via an iOS/Android app on their smartphone – that app will also alert them if they wander too far from their bike.
A replaceable lithium-ion coin cell battery should be good for a claimed two years of use.
Although different in form, the Stemlock from French manufacturer IXOW worked on the same principle (minus the app). It appears to no longer be in production, although the company does now make the non-lockable Stempark, which lets space-conscious users turn their handlebars sideways when the bike is parked in tight quarters.
The Quick Stop Bike Lock is made from machined aluminum and brass, weighs 470 g (1 lb) and adds 44 mm (1.75 inches) to a bike's handlebar height. It's presently on Kickstarter, with a pledge of US$60 getting you one – when and if they reach production, that is. The planned retail price is $88.
Sources: Kickstarter, Quick Stop