Originally Posted by
CliffordK
The lock appears to be around the chain+chainring. You would get about 1/2 crank revolution before experiencing "chain suck". Of course, with a freewheel/freehub, you could pedal 1/2 revolution, then backpedal 1/2 revolution, and repeat.
Certainly not the bike security method to end all bike security methods! But easy enough to put the bike in low gear and orient the lock so that 1/2 of that 1/2 rotation is the cranks turning through top dead center/bottom dead center.
Horses for courses. Down at the public library in my quiet town you'll find unlocked bikes. A little pocketable padlock like this would make your bike the most secure one in the rack.